Reason Foundation - Authors > Joel Schwartz

Burying Evidence

info@reason.org (Joel Schwartz) — Tue, 16 Jan 2007 00:00:00 EST

Introduction

In Digging Up Trouble: The Health Risks of Construction Pollution in California, the Union of Concerned Scientists (UCS) claims air pollution from construction vehicles is killing more than 1,100 Californians each year, sending similar numbers to the hospital, and sickening hundreds of thousands more.[1] UCS estimates the economic toll at more than $9 billion per year. Fortunately, these claims have little to do with reality. UCS exaggerates harm from air pollution by excluding contrary evidence and ignoring weaknesses in studies that support its predetermined conclusions.

According to UCS, the harm from construction emissions results mainly from two air pollutants: particulate matter (PM) and ozone. PM can be directly emitted (e.g., diesel smoke) or formed in the atmosphere from gaseous emissions (e.g., nitrogen oxides (NOx) can be converted to particulate nitrate). The California Air Resources Board (CARB) estimates that construction equipment contributes 3 percent of statewide direct fine particulate matter (PM_2.5) emissions and 28 percent of PM_2.5 emissions from diesel vehicles specifically.[2] Ozone is not directly emitted, but is formed in the atmosphere through reactions of NOx and volatile organic compounds (VOC) in the presence of sunlight. CARB estimates that construction equipment contributed 11 percent of statewide NOx emissions and 5 percent of VOC in 2005.[3]

Construction equipment is thus a significant contributor to total air pollutant emissions. Nevertheless, the actual harm from these emissions is far lower than UCS claims:

Laboratory studies indicate that current, historically low levels of air pollution are at worst a minor factor in people�s health.[4] Health researchers have been unable to kill laboratory animals even with particulate matter at concentrations many times greater than the most polluted California air. Laboratory studies with human volunteers, including asthmatics, have not found harm from PM_2.5 even at concentrations a few times greater than the highest real-world levels. This is true even for components of PM, such as diesel soot, that would be expected to have the highest toxicity. UCS does not mention or include any of this evidence in its report.
Instead, UCS bases its health claims on the results from a much weaker type of study design called an "observational" epidemiology study. Observational studies work with non-randomly selected subjects and non-randomly assigned pollution exposures and then use statistical techniques to try to remove the biases inherent in non-random data. Unfortunately, a range of evidence shows that observational studies are unreliable and tend to create an appearance of risk where no risk in fact exists. UCS does not mention the weaknesses in its chosen form of evidence. Furthermore, even with their inherent biases, many observational studies have not found any harm associated with air pollution, yet UCS omits this contrary evidence from its analysis as well.
UCS assumes that NOx emissions from construction equipment increase ozone, but in fact NOx emissions reduce ozone. A range of air pollution research has shown that when the ratio of VOC to NOx in air is relatively low�a condition typical in California�s metropolitan areas�reducing NOx increases ozone, and vice versa. The key evidence is that total NOx levels decline substantially on weekends, mainly due to reductions in the use of diesel trucks and construction equipment, but ozone levels rise.
UCS exaggerates Californians� exposure to air pollution. For example, UCS claims "more than 90 percent of Californians live in areas that do not comply with the federal ozone standard." The real percentage is only one-third of what UCS claims. UCS generated its exaggerated value by counting "clean" areas as "dirty." For example, even though 99 percent of people in San Diego County live in areas that comply with the federal 8-hour ozone standard, UCS counts all 3 million San Diegans as living in an area that violates the standard. Thus, in addition to exaggerating the harm from any given level of air pollution, UCS also exaggerates the air pollution levels themselves.

At high enough concentrations diesel exhaust can be an unpleasant and aggravating nuisance. But this is a far cry from UCS�s accusation that more than a thousand people are killed each year or that hundreds of thousands suffer serious harm from construction-related emissions.

UCS has vilified the Bush administration, sometimes with good reason, for manipulating scientific research for political purposes, and has even created a whole campaign and Web site to expose and condemn the politicization of science. Yet, in Digging Up Trouble UCS itself puts on a clinic in the selective use of scientific evidence to reach predetermined conclusions and support extra-scientific political goals.[5] The remainder of this commentary provides a more detailed critique of UCS�s misleading account of the health effects of current, historically low air pollution levels.[6]

Evaluating the Real Risks

UCS attributes 98 percent of the harm from construction emissions to premature deaths supposedly caused by PM_2.5 and ozone.[7] But these deaths are statistical figments rather than real harm from air pollution.

UCS implicitly attributes about 40 percent of the air pollution-related deaths from construction equipment to nitrate PM caused by NOx emissions.[8] However, laboratory research on animals and human volunteers indicates that nitrates are not toxic, even at levels many times greater than ever occur in the most polluted California air.[9] UCS assumes all particulate matter has the same health effects, regardless of composition, and does not mention any of the evidence showing that nitrate PM is not harmful. Right off the bat these data reduce UCS�s death claim by 40 percent.

UCS attributes another 10 percent of deaths to ozone caused by NOx and VOC emissions.[10] But emissions from construction equipment actually cause a net decrease in ozone. The reason is that when there is a low ratio of VOC to NOx in air, NOx becomes a net ozone destroyer. Under this circumstance, reducing NOx actually increases ozone.[11] This is the situation in much of California and has been for at least a decade. For example, in the Los Angeles region, NOx levels are about 25 percent to 40 percent lower on Sundays than on weekdays, but ozone levels are 20 percent to 50 percent higher.[12] Even though weekends account for only 29 percent of all days of the year, nearly 50 percent of 8-hour ozone exceedance days in the Los Angeles metro area occur on weekends. San Diego and the San Francisco Bay Area similarly have lower NOx and higher ozone on weekends.

NOx levels drop so much on weekends because diesel vehicles�such as construction equipment�are a large source of NOx and these vehicles are much less active on weekends.[13] The evidence suggests that NOx reductions are the cause of the increase in weekend ozone levels.[14] Thus, regardless of the health effects of ozone, construction emissions reduce ozone. Knock off another 10 percent of the deaths and health costs UCS claims for construction emissions. Despite its claim to be a group of scientists that bases its claims on scientific research, UCS does not mention any of the substantial scientific literature on the role of NOx emissions in reducing ozone levels in California.

Diesel smoke is more noxious than nitrate PM, as anyone who has ever stood near the exhaust pipe of an old school or transit bus can attest. Yet, even diesel smoke and PM_2.5 in general show little evidence for harm at the relatively low exposure levels that occur in the real world today. For example, two separate Health Effects Institute (HEI) studies exposed both healthy and asthmatic human volunteers to 100 µg/m³ of diesel particulate matter (DPM) and 200 µg/m³ of Los Angeles-area PM_2.5 for 2 hours while they exercised.[15]

Both of these are high exposures when compared with PM_2.5 levels people out in the real world experience. Recent measurements next to one of the busiest freeways in Los Angeles found that black carbon, a major component of diesel smoke, never exceeded 10 µg/m³ and averaged 5.4 µg/m³.[16] In terms of total PM_2.5, even Riverside, California, which has the highest PM_2.5 levels in the United States, never reaches 200 µg/m³ of total PM_2.5 and only rarely exceeds even 100 µg/m³. Despite the relatively high particulate exposure levels in the HEI study, the researchers did not find changes in symptoms or lung function in either the healthy or asthmatic subjects.

Animal studies can use much higher PM levels than studies with human volunteers. Yet diesel soot and ambient PM_2.5 do not cause premature death in animals until concentrations reach levels tens to hundreds of times greater than would ever be experienced in ambient air.[17] As a recent review concluded:

It remains the case that no form of ambient PM�other than viruses, bacteria, and biochemical antigens�has been shown, experimentally or clinically, to cause disease or death at concentrations remotely close to US ambient levels.

[18]

Thus, the weight of the evidence from controlled studies with animals and human volunteers suggests that PM is unlikely to cause premature death or other serious health effects at levels found in real-world air. UCS does not mention any of these research results or even imply that there is any evidence at all against the claims it makes in Digging Up Trouble.

The studies discussed above randomly assigned subjects to "treatment" and "control" groups. Random assignment ensures that the treatment and control groups differ only in whether they are exposed to air pollution. Thus, any observed health effects can be more confidently attributed to air pollution and not to other unrelated factors. This type of study is the "gold standard" for sorting out whether a given factor�for example, a new drug, a change of diet, an air pollutant, etc.�really affects health.

Like UCS, other environmental activists, as well as government regulators, have ignored the evidence from controlled studies. Instead, they cite results from a much weaker type of study design called an "observational" study. Observational studies work with non-randomly selected subjects and non-randomly assigned pollution exposures and then use statistical methods to try to remove the biases inherent in non-random data. Most epidemiological studies you read about in the newspaper�studies that assess the effects of diet or health habits on risk of cancer or heart disease, for example�are of this non-randomized, observational sort.

The output of an observational epidemiology study is a correlation between some factor, say air pollution levels or dietary fat, and a health outcome, such as death, atherosclerosis, or an asthma attack. But unlike controlled laboratory studies, which produce direct evidence for cause-effect relationships, the evidence from observational studies is indirect. The implicit assumption in an observational study is that after researchers have controlled for all known sources of bias, any residual correlation between, say, air pollution and risk of death represents a genuine causal connection. However, several lines of evidence indicate that this assumption is false, and that observational studies instead tend to turn up false indications of risk.

Publication Bias and Data Mining

First, it is nearly impossible to control for all of the biases inherent in non-random data, because most of these biases are either unmeasured or unknown. Second, phenomena known as "publication bias" and "data mining" exaggerate the apparent size of any given health effect reported in the epidemiologic literature and encourage researchers to "find" what they are looking for.

Publication bias refers to the tendency of researchers to seek publication of, and for scientific journals to accept for publication, mainly those studies that find a statistically significant effect, while not publishing studies that do not find an effect. As a result, the real effect of any particular air pollutant, diet, medical intervention, etc., is smaller than the studies in the scientific literature would na�vely lead one to believe.

Data mining refers to the risk that observational studies can become statistical fishing expeditions that turn up chance correlations, rather than real causal relationships. Think of the statistical models that researchers use to control for bias in observational studies as having lots of "dials" or "knobs" that the researchers can turn in order to "tune" the statistical model until it fits the observations. Within the presumed uncertainties in the data and methods, researchers tend to turn these knobs and dials in ways that maximize the effects they "expect" or "hope" to find, and are more likely to seek publication of studies that find the expected effect.

Researchers have been aware of these problems for a long time.[19] Here is a recent caution on publication bias from a group of air pollution epidemiologists:

Publication bias arises because there are more rewards for publishing positive or at least statistically significant findings. It is a common if not universal problem in our research culture�In the field of air pollution epidemiology, the question of publication bias has only recently begun to be formally addressed.

[20]

Air pollution epidemiologists have also noted that it is common for researchers to selectively report results for statistical models that maximize the apparent risks of air pollution, rather than the full ensemble of results of their statistical modeling:

Estimation of very weak associations in the presence of measurement error and strong confounding is inherently challenging. In this situation, prudent epidemiologists should recognize that residual bias can dominate their results. Because the possible mechanisms of action and their latencies are uncertain, the biologically correct models are unknown. This model selection problem is exacerbated by the common practice of screening multiple analyses and then selectively reporting only a few important results.[21] (emphasis added)

each study can generate a large number of results for various outcomes, pollutants and lags and there is quite possibly bias in the process of choosing amongst them for inclusion in a paper.

[22]

Publication bias and data mining are not merely speculative concerns. They are serious problems in air pollution epidemiology and health research in general. In just the last few years much conventional medical wisdom that was based on observational epidemiology studies has been tested and overturned by randomized controlled trials that eliminate the biases inherent in observational studies.[23] Spurious results from observational studies have become such a pervasive problem in the medical literature that health researchers have been creating new journals specifically designed to combat publication bias and data mining.[24] A number of epidemiologists believe that observational epidemiology methods are not even capable of providing reliable evaluations of health risks, especially when the putative risks are relatively small, as they are for air pollution.[25]

Epidemiologists have also provided direct evidence that observational studies of air pollution and health are generating false indications of risk.[26] Furthermore, the key observational studies that regulators and activists use to justify their air pollution health claims suffer from spurious and biologically implausible results.

For example, UCS cites two research reports from the American Cancer Society (ACS) study of particulate matter and mortality as the evidence for premature death from long-term exposure to PM_2.5.[27] But these same two reports concluded that PM_2.5 appeared to kill men but not women, those who said they were moderately active but not those who said they were either very active or sedentary, and those with no more than a high school degree but not those with at least some college-level education. These biologically implausible outcomes suggest that the ACS results reflect uncontrolled statistical biases rather than real harm from pollution.

The Health Effects Institute (HEI) performed sensitivity analyses on the ACS data that provided additional evidence that its results were merely statistical artifacts. For example, when migration rates into and out of various cities over time were added to the ACS statistical model relating PM_2.5 and risk of death, the apparent effect of PM_2.5 disappeared.[28] Cities that lost population during the 1980s�Midwest "rust belt" cities�also had higher PM_2.5 levels. People left these cities, which were in economic decline, in search of work in more economically dynamic parts of the country. But people who work and have the wherewithal to migrate also tend to be healthier than the average person. Hence, what appeared to be an effect of PM_2.5 was actually the result of relatively healthier people leaving cities with higher-than-average pollution levels. Migration was just one of several confounding factors that diminished or erased the apparent harm from PM_2.5 but were not accounted for by the ACS researchers. Incidentally, UCS ignores two other major studies that did not find any harm from long-term PM_2.5 exposure.[29]

Another HEI effort, the National Morbidity, Mortality and Air Pollution Study (NMMAPS), reported that in about one-third of the 90 cities evaluated, higher levels of particulate matter and ozone were associated with lower risks of premature death.[30] How could air pollution kill people in some cities but save them in others? More likely both effects are the spurious result of uncontrolled statistical biases.

Not the Whole Truth

Digging Up Trouble includes many more examples of UCS exaggerating or cherry-picking the evidence. For example, UCS claims "as much as 10 to 20 percent of all summertime hospital visits and admissions for respiratory illness are associated with ozone�"[31] But not even CARB or EPA claim anywhere near this large a health burden from ozone and UCS claims to base its health effects estimates on the same studies that CARB and EPA use.[32] When CARB adopted a tougher ozone standard for California, agency staff estimated that eliminating virtually all human-caused ozone in the state would reduce asthma-related emergency-room visits by 1.75 percent and respiratory hospital admissions by 1.2 percent.[33] EPA scientists estimated similarly small health benefits from reducing ozone.[34] Compared to the regulators' estimates, UCS overstates the harm from ozone by at least a factor of six.

But even the small impact of ozone claimed by CARB and EPA is still an exaggeration of the real harm, because both agencies ignored contrary evidence. For example, when assessing the potential benefits of a tougher ozone standard, CARB�s staff omitted a study in California�s Central Valley that found that higher ozone was associated with a lower rate of hospital visits.[35] CARB was certainly aware of the existence of this study, because CARB funded and published it.

According to Digging Up Trouble PM_2.5 also contributes to respiratory hospital visits and asthma symptoms.[36] But UCS ignores a study of several hundred asthmatic children in Connecticut that did not find any association between PM_2.5 and asthma symptoms.[37]

The two studies just cited, the Central Valley study and the Connecticut study, are signal examples of how the overall evidence in the research literature is far more equivocal than advocates make it appear. The Central Valley study reported harm from PM, but not ozone. The Connecticut study reported harm from ozone, but not PM. Regulators and activists mention only the PM results from the Central Valley study and only the ozone results from the Connecticut study, creating an appearance of consistency and robustness in the research base that does not in fact exist.

Data from California and elsewhere in the United States also show that hospital visits for asthma attacks are lowest in July and August�the months when ozone concentrations are at their highest.[38] UCS ignores this evidence as well.

UCS claims that ozone from construction emissions causes more than 300,000 school absence days each year.[39] As shown above, construction emissions actually reduce ozone. Regardless, UCS was selective in choosing its evidence on whether higher ozone is associated with an increase in school absences. UCS cites a CARB health effects report as the source its claims of school absences due to ozone.[40] CARB in turn cites Gilliland et al. (2001), which used data from CARB�s Children�s Health Study (CHS), a long-term study of thousands of California children living in communities with a wide range of pollution levels.[41]

CARB and UCS ignored the biological implausibility of the results in Gilliland et al. For example, an absence from school on a given day appeared to be due mainly to ozone levels from one or two weeks ago, rather than ozone levels during the previous few days. Spending more time outdoors, which would have increased ozone exposures, was paradoxically associated with fewer school absences. Particulate matter was associated with a large increase in non-illness-related absences, but not with absences due to illness. Taken as a whole, the study�s results are not credible and are an additional example of the problems with observational studies.

UCS and CARB also fail to mention that two other studies have been published using the exact same CHS dataset, but did not find an association between ozone and school absences.[42] This is another example not only of UCS�s selective use of evidence to support its pre-determined conclusions, but also of the unreliability of observational studies for assessing health risks, since three different studies using the same data came up with three different results.[43]

Overexposure

In addition to exaggerating the health effects of any given level of air pollution, UCS creates a false appearance that elevated air pollution is more widespread than it really is. According to UCS "more than 90 percent of Californians live in areas that do not comply with the federal ozone standard." This is one of those claims that contains a technical grain of truth, but that leads readers to draw conclusions that are false.

EPA and CARB classify entire regions as "non-attainment" areas under the Clean Air Act even if only a single pollution monitor in the region violates a federal pollution standard. This makes sense from a regulatory perspective, because emissions in one part of a region can affect pollution levels in other parts. But UCS�s implication here is that more than 90 percent of Californians actually breathe air that does not comply with the federal ozone standard. This claim is high by about a factor of three.

For example, San Diego County violates the federal 8-hour ozone standard, but only at a single rural monitoring site in the town of Alpine. The other 99 percent of San Diego County�s 3 million residents breathe air that meets the 8-hour standard, but UCS still counts all of them as breathing air that violates the standard. Even about 65 percent of Los Angeles County�s 10 million residents breathe air that complies with the 8-hour standard, as does everyone in the San Francisco Bay Area. Overall, about 30 percent of Californians live in areas that violate the federal 8-hour ozone standard�just one-third of what UCS claims.

Conclusion

In summarizing its case for harm from air pollution UCS states:

Numerous epidemiological studies tracking thousands of individuals have linked PM exposure to premature death as well as cardiovascular and respiratory illnesses. Similar studies have been carried out for exposure to ozone pollution�The health effects quantified in this report are based on peer-reviewed epidemiological studies used by both the EPA and CARB to evaluate the benefits of reducing air pollution. These studies establish a statistically significant relationship between exposure to PM and ozone and increased incidences of specific health endpoints�The uncertainty in these estimates is quantified by presenting results as both a mean estimate of the number of incidences and a range of estimates representing the 95 percent confidence interval.

[44]

This statement has the appearance of a weight-of-the-evidence scientific review, but it is misleading and disingenuous. First, UCS fails to mention the existence of a large body of evidence that contradicts its claims. Second, UCS implies that peer review provides quality assurance. But despite being peer reviewed, a large fraction of published epidemiology studies have little to do with reality.[45]

Third, UCS creates the false impression that the statistical certainty measure used�the 95 percent confidence interval�represents the real uncertainty in the estimates of air pollution�s health effects derived in Digging Up Trouble. But the 95 percent confidence interval is a measure of real uncertainty only if the study subjects have been randomly selected and randomly assigned to pollution exposures, neither of which are the case in the studies UCS uses for its health effects claims. The 95 percent confidence interval isn�t meaningful unless the biases created by non-random data, data mining, and publication bias have been removed.

At high enough concentrations, diesel exhaust can be an unpleasant and aggravating nuisance. But this is a far cry from UCS�s accusation that more than a thousand people are killed each year or that hundreds of thousands suffer serious harm from construction-related air emissions. The weight of the evidence suggests that air pollution at current, historically low levels is a minor factor in people�s health.[46]

According to its Web site, UCS "stands out among nonprofit organizations as the reliable source for independent scientific analysis."[47] UCS also leads a "scientific integrity" campaign devoted to opposing the manipulation of scientific research results for political ends. However, in Digging Up Trouble UCS selects and structures information to create the appearance of scientific support for its apparently predetermined conclusions about the health risks of air pollution from construction vehicles. The report fails to live up to UCS's own standards.

Joel Schwartz is a Visiting Fellow with the American Enterprise Institute.

Endnotes

[1] Union of Concerned Scientists, Digging Up Trouble: The Health Risks of Construction Pollution in California (Berkeley, CA: December 2006), http://www.ucsusa.org/assets/documents/clean_vehicles/Digging-up-Trouble.pdf.

[2] These percentages include only exhaust emissions. CARB also estimates that dust kicked up by "construction and demolition" accounted for about 5 percent of direct PM_2.5 emissions. Presumably some of these emissions are due to the movement of construction equipment on unpaved surfaces. It doesn�t appear that UCS included these emissions in its estimates. 2005 is the year for which UCS estimated the health impacts of air pollution from construction equipment. California Air Resources Board, "Forecasted Emissions by Summary Category," last updated February 2, 2006, http://www.arb.ca.gov/app/emsinv/ccos/fcemssumcat_cc214.php; California Air Resources Board, "California Off-Road Diesel Fueled Equipment Inventory," October 2006, http://www.arb.ca.gov/msprog/ordiesel/documents/tier_distribution_table.pdf.

[3] Ibid.

[4] Air pollution has been dropping for as long as we�ve been measuring it�which means since the early or mid 1900s in some cases. California and national air pollution emissions and ambient concentrations are at historic lows and continue to decline. For summary national trends in air pollution levels from 1980-2005, see www.epa.gov/airtrends and click on any of the pollutants for a trend graph. For California ozone and PM₁₀ trend data, see http://www.arb.ca.gov/adam/cgi-bin/db2www/polltrendsb.d2w/start. For California air toxics (i.e., benzene, 1,3-butadiene) trend data, see http://www.arb.ca.gov/adam/toxics/toxics.html. Some areas, including Los Angeles and Pittsburgh, have data going back to the early- or mid-20th Century. See, for example, C. I. Davidson, "Air Pollution in Pittsburgh: A Historical Perspective," Journal of the Air Pollution Control Association 29 (1979): pp. 1035-41; J. H. Ludwig, G. B. Morgan and T. B. McMullen, "Trends in Urban Air Quality," EOS 51 (1970): pp. 468-75; H. W. Ellsaesser, "Trends in Air Pollution in the United States," in The State of Humanity, ed. J. L. Simon (Malden, MA: Blackwell, 1995), pp. 491-502.

[5] For more detailed discussions of popular portrayals of evidence on air pollution levels and health effects, see, for example, J. Schwartz, Air Quality: Much Worse on Paper Than in Reality (Washington, DC: American Enterprise Institute, May 2005), http://www.aei.org/docLib/20050602_EPOMay_Junenewg%282%29.pdf; J. Schwartz, Air Pollution and Health: Do Popular Portrayals Reflect the Scientific Evidence? (Washington, DC: American Enterprise Institute, May 2006), http://www.joelschwartz.com/pdfs/AirPoll_Health_EPO_0506.pdf; J. Schwartz, "Air Pollution: Why Is Public Perception So Different from Reality?" Environmental Progress 25 (2006): pp. 291-97.

[6] See note 4 for summary information on air pollution trends.

[7] UCS claims construction-related air pollution causes $9.14 billion per year in harm, of which $8.94 billion represents premature death.

[8] UCS doesn�t make this explicit. However, Digging Up Trouble cites CARB�s health-effects report on goods movement in California as the source for its air pollution death claims. CARB attributes 40 percent of premature deaths to nitrate PM specifically. The percentage breakdown for construction equipment might be a few percentage points higher or lower than for goods movement. There�s no easy way to know for sure, because Digging Up Trouble provides only cursory information on the methodology used to derive its estimates, and does not provide any quantitative breakdowns of its results beyond the summary estimates of total health effects from all construction-related air pollution. In the absence of these details, I use CARB�s goods-movement results as a reasonable ballpark breakdown of the fraction of all health effects contributed by the various components of construction-related air pollution. See California Air Resources Board, Quantification of the Health Impacts and Economic Valuation of Air Pollution from Ports and Goods Movement in California (Sacramento, CA: March 21, 2006), http://www.arb.ca.gov/planning/gmerp/march21plan/appendix_a.pdf, p. A-75.

[9] L. C. Green and S. R. Armstrong, "Particulate Matter in Ambient Air and Mortality: Toxicologic Perspectives," Regulatory Toxicology and Pharmacology 38 (2003): pp. 326-35; M. T. Kleinman, W. S. Linn, R. M. Bailey et al., "Effect of Ammonium Nitrate Aerosol on Human Respiratory Function and Symptoms," Environmental Research 21 (1980): pp. 317-26; R. B. Schlesinger and F. Cassee, "Atmospheric Secondary Inorganic Particulate Matter: The Toxicological Perspective as a Basis for Health Effects Risk Assessment," Inhalation Toxicology 15 (2003): pp. 197-235; M. J. Utell, A. J. Swinburne, R. W. Hyde et al., "Airway Reactivity to Nitrates in Normal and Mild Asthmatic Subjects," Journal of Applied Physiology 46 (1979): pp. 189-96.

[10] See note 8 for how this estimate was derived.

[11] J. H. Seinfeld, "Urban Air Pollution: State of the Science," Science 243 (1989): pp. 745-52.

[12] Based on hourly ozone and NOx monitoring data for 1997�2001 downloaded from the California Air Resources Board�s Web site, http://www.arb.ca.gov/aqd/aqdcd/aqdcddld.htm.

[13] C. L. Blanchard and S. J. Tannenbaum, "Differences between Weekday and Weekend Air Pollutant Levels in Southern California," Journal of the Air & Waste Management Association 53 (2003): pp. 816-28; E. M. Fujita, D. E. Campbell, B. Zielinska et al., "Diurnal and Weekday Variations in the Source Contributions of Ozone Precursors in California�s South Coast Air Basin," Journal of the Air & Waste Management Association 53 (2003): pp. 844-63; R. A. Harley, L. C. Marr, J. K. Lehner et al., "Changes in Motor Vehicle Emissions on Diurnal to Decadal Time Scales and Effects on Atmospheric Composition," Environmental Science and Technology 39 (2005): pp. 5356-62.

[14] Blanchard and Tannenbaum, "Differences between Weekday and Weekend Air Pollutant Levels in Southern California"; C. L. Blanchard and S. J. Tannenbaum, "Weekday/Weekend Differences in Ambient Air Pollutant Concentrations in Atlanta and the Southeastern United States," Journal of the Air & Waste Management Association 56 (2006): pp. 271-84; E. M. Fujita, W. R. Stockwell, D. E. Campbell et al., "Evolution of the Magnitude and Spatial Extent of the Weekend Ozone Effect in California�s South Coast Air Basin 1981-2000," Journal of the Air & Waste Management Association 53 (2003): pp. 864-75; Harley, Marr, Lehner et al., "Changes in Motor Vehicle Emissions on Diurnal to Decadal Time Scales and Effects on Atmospheric Composition"; D. R. Lawson, "The Weekend Effect�the Weekly Ambient Emissions Control Experiment," Environmental Manager (July 2003): pp. 17-25; L. C. Marr and R. A. Harley, "Modeling the Effect of Weekday-Weekend Differences in Motor Vehicle Emissions on Photochemical Air Pollution in Central California," Environmental Science & Technology 36 (2002): pp. 4099-106; L. C. Marr and R. A. Harley, "Spectral Analysis of Weekday-Weekend Differences in Ambient Ozone, Nitrogen Oxide, and Non-Methane Hydrocarbon Time Series in California," Atmospheric Environment 36 (2002): pp. 2327-35; B. K. Pun and C. Seigneur, "Day-of-Week Behavior of Atmospheric Ozone in Three U.S. Cities," Journal of the Air & Waste Management Association 53 (2003): pp. 789-801; R. Torres-Jardon and T. C. Keener, "Evaluation of Ozone-Nitrogen Oxides-Volatile Organic Compound Sensitivity of Cincinnati, Ohio," Journal of the Air & Waste Management Association 56 (2006): pp. 322-33.

[15] H. Gong, Jr., C. Sioutas and W. S. Linn, "Controlled Exposures of Healthy and Asthmatic Volunteers to Concentrated Ambient Particles in Metropolitan Los Angeles" (Boston: Health Effects Institute, 2003); S. T. Holgate, T. Sandstrom, A. J. Frew et al., Health Effects of Acute Exposure to Air Pollution. Part I: Healthy and Asthmatic Subjects Exposed to Diesel Exhaust (Boston: Health Effects Institute, 2003).

[16] Y. Zhu, W. C. Hinds, S. Kim et al., "Concentration and Size Distribution of Ultrafine Particles near a Major Highway," Journal of the Air and Waste Management Association 52 (2002): pp. 1032-42.

[17] Green and Armstrong, "Particulate Matter in Ambient Air and Mortality: Toxicologic Perspectives"; S. H. Moolgavkar, "A Review and Critique of the EPA�s Rationale for a Fine Particle Standard," Regulatory Toxicology and Pharmacology 42 (2005): pp. 123-44.

[18] Green and Armstrong, Ibid.

[19] Publication bias is a well-documented problem in a range of disciplines. See, for example, Victor M. Montori, Marek Smieja and Gordon H. Guyatt, "Publication Bias: A Brief Review for Clinicians," Mayo Clinic Proceedings 75 (2000): pp. 1284-88; Alison Thornton and Peter Lee, "Publication Bias in Meta-Analysis: Its Causes and Consequences," Journal of Clinical Epidemiology 53 (2000): pp. 207-16.

[20] H. Anderson, R. Atkinson, J. Peacock et al., Meta-Analysis of Time-Series Studies and Panel Studies of Particulate Matter (PM) and Ozone (World Health Organization, 2004), www.euro.who.int/document/e82792.pdf.

[21] T. Lumley and L. Sheppard, "Time Series Analyses of Air Pollution and Health: Straining at Gnats and Swallowing Camels?" Epidemiology 14 (2003): pp. 13-14.

[22] Anderson et al., Meta-Analysis of Time-Series Studies and Panel Studies of Particulate Matter (PM) and Ozone.

[23] For example, hormone replacement therapy and Vitamin A turned out not to reduce risk of cardiovascular disease, following a low-fat diet turned out not to reduce risk of heart disease or colorectal and breast cancer, and calcium supplements didn�t reduce the risk of osteoporosis. S. A. Beresford, K. C. Johnson, C. Ritenbaugh et al., "Low-Fat Dietary Pattern and Risk of Colorectal Cancer: The Women�s Health Initiative Randomized Controlled Dietary Modification Trial," Journal of the American Medical Association 295 (2006): pp. 643-54; B. V. Howard, L. Van Horn, J. Hsia et al., "Low-Fat Dietary Pattern and Risk of Cardiovascular Disease: The Women�s Health Initiative Randomized Controlled Dietary Modification Trial," Journal of the American Medical Association 295 (2006): pp. 655-66; G. Kolata, "Big Study Finds No Clear Benefit of Calcium Pills," New York Times, Feburary 16, 2006; Moolgavkar, "A Review and Critique of the EPA�s Rationale for a Fine Particle Standard"; R. L. Prentice, B. Caan, R. T. Chlebowski et al., "Low-Fat Dietary Pattern and Risk of Invasive Breast Cancer: The Women�s Health Initiative Randomized Controlled Dietary Modification Trial," Journal of the American Medical Association 295 (2006): pp. 629-42; G. D. Smith, "Reflections on the Limitations to Epidemiology," Journal of Clinical Epidemiology 54 (2001): pp. 325-31; G. Taubes, "Epidemiology Faces Its Limits," Science 269 (1995): pp. 164-69.

[24] Sharon Begley, "New Journals Bet 'Negative Results' Save Time, Money," The Wall Street Journal, September 15, 2006, p. B1, http://online.wsj.com/article/SB115827169620563571-email.html.

[25] J. P. Ioannidis, "Why Most Published Research Findings Are False," PLoS Med 2 (2005): e124, http://medicine.plosjournals.org/archive/1549-1676/2/8/pdf/10.1371_journal.pmed.0020124-L.pdf; Smith, "Reflections on the Limitations to Epidemiology"; Taubes, "Epidemiology Faces Its Limits."

[26] Anderson, Atkinson, Peacock et al., Meta-Analysis of Time-Series Studies and Panel Studies of Particulate Matter (PM) and Ozone (; M. L. Bell, F. Dominici and J. M. Samet, "A Meta-Analysis of Time-Series Studies of Ozone and Mortality with Comparison to the National Morbidity, Mortality, and Air Pollution Study," Epidemiology 16 (2005): pp. 436-45; K. Ito, "Associations of Particulate Matter Components with Daily Mortality and Morbidity in Detroit," in Revised Analyses of Time-Series Studies of Air Pollution and Health (Boston: Health Effects Institute, 2003); W. R. Keatinge and G. C. Donaldson, "Heat Acclimatization and Sunshine Cause False Indications of Mortality Due to Ozone," Environmental Research 100 (2006): pp. 387-93; G. Koop and L. Tole, "Measuring the Health Effects of Air Pollution: To What Extent Can We Really Say That People Are Dying from Bad Air?" Journal of Environmental Economics and Management 47 (2004): pp. 30-54.

[27] D. Krewski, R. T. Burnett, M. S. Goldberg et al., Reanalysis of the Harvard Six Cities Study and the American Cancer Society Study of Particulate Air Pollution and Mortality (Boston: Health Effects Institute, July 2000); C. A. Pope, 3rd, R. T. Burnett, M. J. Thun et al., "Lung Cancer, Cardiopulmonary Mortality, and Long-Term Exposure to Fine Particulate Air Pollution," Journal of the American Medical Association 287 (2002): pp. 1132-41.

[28] Krewski, Burnett, Goldberg et al., Reanalysis of the Harvard Six Cities Study and the American Cancer Society Study.

[29] J. E. Enstrom, "Fine Particulate Air Pollution and Total Mortality among Elderly Californians, 1973-2002," Inhalation Toxicology 17 (2005): pp. 803-16; F. W. Lipfert, H. M. Perry, J. P. Miller et al., "The Washington University-EPRI Veterans� Cohort Mortality Study," Inhalation Toxicology 12 (suppl. 4) (2000): pp. 41-73.

[30] M. L. Bell, A. McDermott, S. L. Zeger et al., "Ozone and Short-Term Mortality in 95 US Urban Communities, pp. 1987-2000," Journal of the American Medical Association 292 (2004): pp. 2372-8; F. Dominici, A. McDermott, M. Daniels et al., Revised Analyses of the National Morbidity, Mortality, and Air Pollution Study (Boston: Health Effects Institute, May 2003).

[31] UCS, p. 7.

[32] See UCS, p. 25. UCS says its health effects estimates are derived from health studies cited in the following reports from CARB and EPA: California Air Resources Board, Appendix A. Quantification of the Health Impacts and Economic Valuation of Air Pollution from Ports and Goods Movement in California (Sacramento: March 21, 2006), http://www.arb.ca.gov/planning/gmerp/march21plan/appendix_a.pdf; Environmental Protection Agency, Final Regulatory Analysis: Control of Emissions from Nonroad Diesel Engines (Washington, DC: May 2004), http://www.epa.gov/nonroad-diesel/2004fr/420r04007a.pdf.

[33] CARB�s report does not provide these percentages explicitly. Instead, in one part of its staff report CARB estimates the number of incidences of various health effects avoided by reducing ozone. Another part of the report provides estimates of the total number of incidences of each health effects. Dividing the former by the latter gives the fraction of health effects avoided by reducing ozone. I demonstrate this in J. Schwartz, Rethinking the California Air Resources Board�s Ozone Standards (Washington, DC: American Enterprise Institute, September 2005), http://www.aei.org/doclib/20050912_Schwartzwhitepaper.pdf. For CARB�s estimates, see California Air Resources Board, Review of the California Ambient Air Quality Standard for Ozone (Sacramento: March 2005), http://www.arb.ca.gov/research/aaqs/ozone-rs/ozone-final/ozone-final.htm.

[34] Once again, EPA does not provide explicit percentage changes, but the percentage changes can be calculated from data provided in a journal article by EPA�s scientists. See B. J. Hubbell, A. Hallberg, D. R. McCubbin et al., "Health-Related Benefits of Attaining the 8-Hr Ozone Standard," Environmental Health Perspectives 113 (2005): pp. 73-82; Schwartz, Rethinking the California Air Resources Board�s Ozone Standards.

[35] S. F. van den Eeden, C. P. Quesenberry, J. Shan et al., Particulate Air Pollution and Morbidity in the California Central Valley: A High Particulate Pollution Region (Sacramento: California Air Resources Board, July 2002).

[36] UCS, p. 9.

[37] J. F. Gent, E. W. Triche, T. R. Holford et al., "Association of Low-Level Ozone and Fine Particles with Respiratory Symptoms in Children with Asthma," Journal of the American Medical Association 290 (2003): pp. 1859-67.

[38] For data on asthma emergency room visits and hospitalizations by month, see, for example, Spokane Regional Health District, Asthma in Spokane County (Spokane, WA: April 2002), http://www.srhd.org/information/pubs/pdf/factsheets/AsthmaInSpokaneCounty.pdf; J. K. Stockman, N. Shaikh, J. von Behren et al., California County Asthma Hospitalization Chart Book, Data from 1998-2000 (Sacramento: California Department of Health Services, September 2003), http://www.ehib.org/cma/papers/Hosp_Cht_Book_2003.pdf; Texas Department of Health, Asthma Prevalence, Hospitalizations and Mortality � Texas, 1999-2001 (Austin: November 21, 2003), http://www.tdh.state.tx.us/cphpr/asthma/asthma.pdf; K. Tippy and N. Sonnenfeld, Asthma Status Report, Maine 2002 (Augusta, ME: Maine Bureau of Health, November 25, 2002); K. R. Wilcox and J. Hogan, An Analysis of Childhood Asthma Hospitalizations and Deaths in Michigan, 1989-1993 (Lansing, MI: Michigan Department of Community Health, undated), http://www.michigan.gov/documents/Childhood_Asthma_6549_7.pdf.

[39] UCS, p. 9.

[40] California Air Resources Board, Appendix A. Quantification of the Health Impacts and Economic Valuation of Air Pollution from Ports and Goods Movement in California.

[41] F. D. Gilliland, K. Berhane, E. B. Rappaport et al., "The Effects of Ambient Air Pollution on School Absenteeism Due to Respiratory Illnesses," Epidemiology 12 (2001): pp. 43-54.

[42] K. Berhane and D. C. Thomas, "A Two-Stage Model for Multiple Time Series Data of Counts," Biostatistics 3 (2002): pp. 21-32; V. Rondeau, K. Berhane and D. C. Thomas, "A Three-Level Model for Binary Time-Series Data: The Effects of Air Pollution on School Absences in the Southern California Children�s Health Study," Statistics in Medicine 24 (2005): pp. 1103-15.

[43] There are other reasons to conclude that the claim of a connection between ozone and school absences is not credible. For details, see pp. 28-30 in Schwartz, Rethinking the California Air Resources Board�s Ozone Standards.

[44] UCS, p. 25.

[45] Ioannidis, "Why Most Published Research Findings Are False"; Smith, "Reflections on the Limitations to Epidemiology"; Taubes, "Epidemiology Faces Its Limits"; Begley, "New Journals Bet �Negative Results� Save Time, Money."

[46] See note 4 for summary information on air pollution trends.

[47] UCS, "About UCS," http://www.ucsusa.org/ucs/about/.

Let's Pretend

info@reason.org (Joel Schwartz) — Fri, 22 Oct 2004 00:00:00 EDT

Tech Central Station

Given the choice between heaven and purgatory, which would you choose? Most rational people would choose heaven. Thus, it wasn't surprising that when given a choice between an idealized urban village and a suburban nowheresville, a survey released by Smart Growth America (SGA) and the National Association of Realtors (NAR) found that most people chose the former.

According to the press release for SGA-NAR's 2004 American Community Survey, "Asked to choose between two communities, six in ten prospective homebuyers chose a neighborhood that offered a shorter commute, sidewalks and amenities like shops, restaurants, libraries, schools and public transportation within walking distance over a sprawling community with larger lots, limited options for walking and a longer commute."

SGA and NAR were able to elicit this outcome only by presenting survey respondents with carefully structured information and choices. Respondents were given a choice between a community with one-acre lots and a 45-minute-plus commute or a mixed-use community where everything is within a few blocks of home (see Figure 1). But these aren't the choices real people face. SGA-NAR forced respondents to choose between a suburb that sounds like it's in the middle of nowhere, and an urban nirvana that doesn't exist anywhere. What's extraordinary is that they got only 60 percent of the respondents to choose the latter. Even with the deck stacked against suburbs, an amazing 40 percent of Americans apparently find suburban purgatory superior to urban heaven.

Figure 1. Survey Respondents Had to Choose One of these Two Hypothetical Communities

Source: SGA-NAR, 2004 American Community Survey, p. 4.

What's misleading about these choices? First, few homes are on the large lots imagined by SGA. According to the Census Bureau, 87 percent of new single-family detached homes are built on lots of less than half an acre — the highest lot size for which the data were broken out.[1] Sixty-six percent were on less than a quarter acre. So a realistic suburb would have several times the population density implicit in the SGA-NAR survey.

Second, few Americans commute more than 45 minutes, and the longest commute times occur in the dense urban areas favored by smart growthers. The Census Bureau estimates that the average work commute takes just over 25 minutes, and only 15 percent of workers have a commute longer than 45 minutes.

Of course, a national average could be misleading. Perhaps suburbanites are the ones on the high side of that average. Though it will come as a surprise to those on an information diet high in smart growth orthodoxy, dense cities with extensive public transit systems are where commutes are longest. New York City tips the scales at an average of 38 minutes -- the highest in the U.S. Chicago comes in a distant second at 33 minutes. In contrast, sprawling areas like Atlanta, Houston, and Phoenix are right around the national average.

And it isn't just New York City as a whole that has long commutes. Even in Manhattan, a paragon of density and mixed-use urbanity, the average commute takes about 30 minutes -- 30th out of 233 urban counties ranked by the Census. Thirteen out of the worst 30 counties are in the New York metropolitan area, which consequently accounts for a substantial fraction of the roughly 19 million Americans who suffer those 45-minute-plus commutes. Commuting takes longer in denser cities, because denser cities have more traffic congestion and because traveling by transit, which is more common in denser cities, is slower than traveling by car.[2]

Perhaps more misleading than the fake choices is the vague language used to describe them. Note in Figure 1 that in the smart-growth community respondents are told what kind of housing exists in the area, but not the specific kind of housing they would actually live in. Respondents are also led to believe that everything they would want or need to do (other than work) is within walking distance.

Did people who chose the smart-growth community imagine themselves living in one of the single-family homes or in a townhouse; on a large lot or small one? Would their responses have changed if they were told they had only a 25 percent chance of living in a detached home on more than 1/10th of an acre?

When the respondents imagined all those stores and restaurants and leisure activities within walking distance, were they thinking of a random collection of such amenities, or did they assume they would have their particular favorites nearby? Would their response have changed if they knew what fraction of nearby businesses they would actually patronize, or how often they would need to drive or take transit to get to the specific places where they wanted to shop? If they had time to reflect, would anyone seriously believe there's any community where everyone can have their pasta, sushi, tapas, burritos, bagels, groceries, clothing, books, and half-caf-no-fat lattes all within a few blocks of their house? For good measure, let's add soccer practice, piano lessons, the pediatrician, and the health club.

What people say in surveys and what they actually do are two different things. The reason for the difference between "say" and "do" is that in surveys you don't have to make tradeoffs among a range of competing goals and aspirations, but in the real world you do. When it comes to housing and community, I suspect that what most people really want is something like this:

To live in a single-family home with a substantial yard, within walking distance of their favorite restaurants and stores, on a street with no traffic, and in a neighborhood with little traffic congestion.
A short commute on clear highways, but no highways near their house.
Convenient public transit that other people will use.

Since you can't have all of these things at the same time, people have to make choices and tradeoffs, and they naturally make them based on their particular values, aspirations, and financial means. In the end, most people who can afford it opt for a single-family home with a yard, travel mainly by automobile, and a commute of maybe 20 to 40 minutes on roads that are likely to be relatively congested.

One might argue that these choices are to some extent a function of public policy, rather than innate human aspirations. To be sure, policies such as minimum parking requirements encourage driving, while minimum-lot-size and other zoning requirements can discourage or prevent high-density or mixed-use housing, even when demand for such developments exists. Ideally, we could say good riddance to such meddling. But Europe's experience suggests that space, privacy, and mobility are deep-seated human desires that go well beyond these more marginal policy effects. Even with extensive public transit and five-dollar-per-gallon gasoline, per-capita driving has skyrocketed in European cities during the last few decades, and most residents of European cities live in suburbs that look very much like those in America.[3]

Rather than a program to help Americans achieve their dreams, smart growth seems to be more about helping anti-suburb activists impose their own vision on the rest of society. Smart-growth advocates wish it were otherwise, but people tend to choose a suburban, auto-based lifestyle once they and their society achieve the necessary wealth to afford it.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Notes

[1] There is great variation by region, however. In the Northeast, 68% of houses are built on less than half an acre. In the West, the figure is 95%.

[2] Based on data from the 2001 National Household Travel Survey, in metropolitan areas, the average transit commute takes 56 minutes, while the average automobile commute takes 23 minutes. Although per-capita driving decreases with increasing density, it doesn't decrease nearly enough to offset the concentration of driving into a smaller amount of land area. Peter Gordon, Bumsoo Lee, Harry W. Richardson, "Travel Trends in U.S. Cities: Explaining the 2000 Census Commuting Results" (Los Angeles: Lusk Center for Real Estate, University of Southern California, April 2004), Brian Taylor, "Rethinking Traffic Congestion," Access, Fall 2002, pp. 8-16, Wendell Cox, "How Higher Densities Make Traffic Worse," The Public Purpose, 57, 2003, http://www.publicpurpose.com/pp57-density.htm.

[3] Randall G. Holcombe and Samuel R. Staley eds., Smarter Growth: Market-Based Strategies for Land-Use Planning in the 21st Century.

Smog Hits Record Low in 2004

info@reason.org (Joel Schwartz) — Tue, 12 Oct 2004 00:00:00 EDT

2004 has had the lowest ozone smog levels since states began measuring the stuff back in the 1970s. Based on preliminary data from around the country, days exceeding EPA's tough new 8-hour ozone standard declined an average of about 50 percent below 2003, which was itself a record year.[1]

A combination of continuing emission reductions and favorable weather explains the improvements. Weather is the single largest factor affecting year-to-year variations in smog levels. All else equal, cool, wet, and windy years will have less ozone than warm, dry, and calm ones. But weather is only part of the story. During the last 30 years most of the country has had several years that were cooler and/or wetter than 2004, but never have smog levels been anywhere near this low.

The charts below will give you an idea of how extraordinary 2004 was. Figure 1 shows the average number of days per year exceeding EPA's 1-hour and 8-hour ozone standards at the nation's ozone monitoring sites from 1975 to 2003. For each standard, the chart includes the exceedance rate for all sites operating in any given year (generally about 700 to 1,200), and also for the 261 sites that operated continuously from 1983-2003. The percentages at right give the decline in the number of 8-hour and 1-hour exceedances since 1975.

Note that 2003 was the best year on record, barely edging out 2000, and that the average number of 8-hour ozone exceedances varies greatly from year to year. Annual variations in weather create the large short-term variability in smog levels, but superimposed on this is a long-term decline in ozone exceedances due to emission reductions.

Figure 1. National Trend in Days per Year Exceeding EPA's Ozone Standards, 1970-2003[2]

Figure 1 can't be extended through 2004 until all states have reported their 2004 ozone data. However, preliminary data for 2004 are available on the web for several metropolitan areas and states. Figure 2 compares 8-hour ozone exceedances in 2003 and 2004 for several of these areas. For each area, the chart gives the average number of 8-hour ozone exceedances for all monitoring locations that had data for both years. A similar figure at the end of this column provides data for the worst location in each of the areas in Figure 2.

Note the large declines almost across the board. I wasn't able to locate data for the Midwest in time for this column, but EPA's web site reports that there wasn't a single "ozone action day" in 2004 in all of Illinois, Michigan, Ohio, Wisconsin, and Minnesota, while southern Indiana (the portion in the Louisville, Kentucky metro area) had just one.[3]

Figure 2. Average Number of Days per Year Exceeding the 8-hour Ozone Standard during 2003 and 2004[4]

Overall, 8-hour ozone exceedance days declined an average of about 50 percent between 2003 and 2004, meaning that 2004 is not only the best year on record, but the best by a large margin.

You wouldn't know this from reading activists' reports on air quality, which continue to tell a deceitfully gloomy story. Dangerous Days of Summer from Environmental Defense (ED) and Danger in the Air from the Public Interest Research Group (PIRG) are the two latest entries. Neither report mentions that 2003 and 2004 were the best years in history for ozone. PIRG does mention that 2003 and 2004 were better than 2002, but attributes it all to weather.

Nevertheless, as you might expect, activists are always ready with a press release in years when air pollution rises. When ozone levels spiked upward during the hot, dry summer of 2002, a Clean Air Trust press release proclaimed "New Survey Finds Massive Smog Problem in 2002." But no activist press releases highlighted the spectacular decline in ozone levels the next year, or the record-low ozone levels of the last two years.

Other potential, but unmentioned contributors to the recent ozone improvements are a 60 percent reduction in coal-fired power plant NOx emissions during the May-September "ozone season," implemented in May 2004 under EPA's NOx SIP Call regulation, and an ongoing reduction of about eight percent per year in total automobile emissions due to fleet turnover to cleaner vehicles. Activists avoid mentioning these reductions, because they undermine their claims that urban "sprawl" increases air pollution and that power-plant emissions are increasing.

ED's Dangerous Days commits the full range of deceptions pioneered by the American Lung Association (ALA) in its annual State of the Air series, such as: inflating pollution levels, exaggerating the harm from current air pollution levels and the number of people living in areas that exceed EPA standards, downplaying positive trends, and creating the impression that there will be little or no future improvement without stringent new regulations.

For example, Dangerous Days claims the New York metro area exceeded the 8-hour ozone standard on 22 percent of summer days during 2001-2003. But the average site in the New York area exceeded the 8-hour standard on 10 percent of summer days -- less than half of ED's claim. ED's number is higher than even the worst site in the New York area (Jackson Township, NJ), which exceeded the 8-hour standard 20 percent of the summer.[5] ED likewise inflated ozone levels in all of the country's metro areas.

But Environmental Defense's ozone inflation is even worse than this, because most people in the New York area live in places with the lowest ozone levels. Monitoring sites in the five boroughs of New York City averaged 3.7 percent of summer days exceeding the 8-hour standard, or 1/6^th of ED's claim. Likewise, ED claimed Los Angeles exceeded the 8-hour standard on 50 percent of summer days. But about half of Angelenos live in areas that never exceed the 8-hour standard. ED also fails to distinguish between moderate and high ozone. Most ozone exceedances involved relatively low ozone levels. The average site in the New York metro area exceeded the higher 1-hour ozone standard on only 2 percent of summer days, compared with 10 percent for the 8-hour standard.

Dangerous Days also exaggerates the number of people who live in areas that violate EPA's air standards. According to the report, "Nearly 160 million Americans live in areas where ozone smog levels exceed national standards...Some 99 million Americans live in areas that exceed annual fine particle standards."

Both of these numbers are based on the populations of counties designated as "non-attainment" areas by EPA. But this has little to do with actual pollution levels, because EPA designates whole regions as non-attainment areas even if only a single monitoring location violates a federal standard. This makes sense for air quality planning, but not for determining air pollution exposure. Thus, 94 to 99 percent of people in San Diego, Chicago, Las Vegas, and Phoenix live in areas that meet all EPA ozone standards, but EPA counts everyone in those areas as breathing dirty air.

The claim for fine particulate matter (PM2.5) is misleadingly high for an additional reason: EPA designated some counties as PM2.5 non-attainment areas not because they exceed the PM2.5 standard, but because they are believed to contribute to violations elsewhere. All told, ED overestimates by more than a factor of two the number of people living in areas that violate EPA standards.

Dangerous Days also implies air pollution is responsible for rising asthma rates: "Asthma has increasingly gained attention as a nationwide epidemic and a symbol of the manifold health impacts of air pollution. It is the nation's fastest growing chronic disease..." Yet air pollution can't be a cause of rising asthma, because air pollution of all kinds has been falling nationwide at the same time that asthma has been rising.

Air pollution can aggravate pre-existing respiratory disease, but its impact is nothing close to what groups like ED claim. For example, when the Clinton-era EPA developed the 8-hour ozone standard, it predicted that going from full national attainment of the 1-hour standard to full national attainment of the 8-hour standard would reduce hospital admissions for asthma by 0.6 percent, despite the 8-hour standard's much greater stringency.[6] Data from around the U.S. show that asthma hospitalizations are lowest in July and August-when ozone and, in many areas PM, are highest.[7] Air pollution has gained the "national attention" referred to by ED not because of its overall importance as a cause of disease and disability, but because of its rhetorical power to generate eye-catching headlines, donations, and research funding.

PIRG's Danger in the Air makes ED's Dangerous Days look like a model of reliable analysis. To arrive at its claims about ozone exceedances, PIRG simply adds up the ozone exceedances at each monitoring location in a city or state and calls that the number of exceedances for the area. Thus, PIRG claims Colorado exceeded the 8-hour ozone standard 60 times in 2003, even though the worst location in the state had 15 exceedances, and the average location had less than four. Despite a national average of about four 8-hour ozone exceedances per year in 2003 (see Figure 1), PIRG managed to cook up 4,583 exceedances-a particularly masterful feat when you consider that there are only 365 days in a year. PIRG's method is meaningless for determining health risks or anything else about actual air pollution, but it's great for generating big, scary numbers.

I've often criticized the media for their mostly gloomy and misleading accounts of air quality issues. For example, despite the substantial decline in ozone exceedances since the 1970s (see Figure 1), in a story on ALA's State of the Air 2004 the Washington Post asserted "Ozone pollution has declined slightly over the past 30 years" (emphasis added).[8] But many reporters around the country have noticed this years' unusually low pollution levels and have let the public know about it. Even here, however, most stories gave the impression that mild weather was the sole cause, and failed to discuss the long-term decline in smog-forming emissions or to compare smog levels in 2004 with much higher smog levels in previous years that had favorable weather.

Will air pollution remain just as low next year? That depends largely on the weather. Either way, emissions will continue to decline and the long-term trend will continue downward. Regardless, environmental activists are sure to tell us the sky is falling.

Figure 3. Number of Days per Year Exceeding the 8-hour Ozone Standard at the Worst Site in Each State or Metropolitan Area during 2003 and 2004

Notes: Los Angeles-San Bernardino (LA-SB) and the San Joaquin Valley (SJV) are excluded in order to keep the vertical scale from being too compressed for the other areas. For the record, the 2003 and 2004 values at the worst sites in these areas are as follows: LA-SB, 72 and 62; SJV, 116 and 94. Arvin, the worst area in the SJV, might end up with a few additional ozone exceedances over the next couple of weeks.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

[1] Note that is a statement about nationwide average ozone levels. It doesn't mean that ozone declined everywhere in 2004 or that 2004 was the best year everywhere. Some areas experienced ozone increases in 2004, and 2004 was not necessarily a record year in all areas of the country.

[2] Results are based on analysis of hourly ozone data for 1970 through 2003 downloaded from EPA at http://www.epa.gov/ttn/airs/airsaqs/detaildata/downloadaqsdata.htm.

[3]For a list of ozone action days, in EPA's Region 5, see http://www.epa.gov/region5/air/ozoneday/pastoad.html. Days highlighted in red are ozone action days (OAD) and clicking on the date gives a map showing where the alert occurred. The only OAD occurred in on August 3, 2004. According to EPA Region 5 staff, the OAD listed for May 1, 2004 is a system test and not an actual OAD.

[4] Data sources:
http://www.epa.gov/region1/airquality/o3exceed-04.html,
http://www.tnrcc.state.tx.us/cgi-bin/monops/8hr_monthly,
http://www.marama.org/ozone/2004/index.html,
http://www.marama.org/ozone/2003/index.html,
http://www.arb.ca.gov/adam/cgi-bin/db2www/ ozonereport_annual.d2w/start,
http://www.air.dnr.state.ga.us/tmp/exceedances/,
http://www.cdphe.state.co.us/release/2004/092204b.html,
http://www.epa.gov/air/data/geosel.html,
M. J. Pitzl, "Summer's Ozone Bad Only Once," Arizona Republic, October 2, 2004, p. 3B. Data for 2004 go through September 30^th, except for California, which goes through October 5^th. Houston sometimes has a few 8-hour ozone exceedances in October. To eliminate the chance for bias, I used data only for April through September in both 2003 and 2004 when comparing ozone levels in Texas.

[5] Even this may be an overestimate. ED counted only ozone exceedances that occurred between Memorial Day and Labor Day and then divided by 99 days to get their percentage. Because of time constraints, I've counted ozone exceedances occurring at any time of the year, but I still divide by 99 days. Thus, my numbers represent an upper limit on the percentage of summer days with ozone violations. The actual percentage will be lower in some cases.

[6]Environmental Protection Agency, "National Ambient Air Quality Standards for Ozone: Proposed Decision," Federal Register, December 13, 1996, pp. 65715-65750
http://www.epa.gov/fedrgstr/EPA-AIR/1996/December/ Day-13/pr-23901.txt.html.

[7]Elevated ozone occurs mainly during the summer, because ozone formation increases with increasing sunlight and temperature. Elevated PM occurs mainly in the summer in the east and in the rural west, and in the winter in urban areas of the west. For seasonal PM data see, for example, http://www.netl.doe.gov/publications/proceedings/ 02/PM25/1.1.2Tanner_p.pdf,
http://www.epa.gov/air/airtrends/aqtrnd98/gifs/fig2-57.gif,
http://capita.wustl.edu/CAPITA/Awma98/HTTP/98_A918.htm,
http://capita.wustl.edu/CAPITA/CapitaReports/PMFineAn/ PM_vs_Tran/finalreport/BltPhx_PMvsWnd_FinalReport.html, R. A. Eldred et al., "Composition of PM2.5 and PM10 Aerosols in the Improve Network," Journal of the Air & Waste Management Association, vol. 47 (1997), pp. 194-203.

For seasonal trend in asthma symptoms and hospitalization see, for example, Spokane Regional Health District, Asthma in Spokane County (Spokane, Washington: April 2002), http://www.srhd.org/information/pubs/pdf/factsheets/ AsthmaInSpokaneCounty.pdf, K. Tippy and N. Sonnenfeld, Asthma Status Report, Maine 2002 (Augusta, Maine: Maine Bureau of Health, November 25, 2002), J. F. Gent et al., "Association of Low-Level Ozone and Fine Particles with Respiratory Symptoms in Children with Asthma," Journal of the American Medical Association, vol. 290, no. 14 (2003), pp. 1859-1867, Texas Department of Health, Asthma Prevalence, Hospitalizations and Mortality - Texas, 1999-2001 (Austin: November 21, 2003), http://www.tdh.state.tx.us/cphpr/asthma/asthma.pdf, J. K. Stockman et al., California County Asthma Hospitalization Chart Book, Data from 1998-2000 (Sacramento: California Department of Health Services, September 2003), http://www.ehib.org/cma/papers/ Hosp_Cht_Book_2003.pdf, K. R. Wilcox and J. Hogan, An Analysis of Childhood Asthma Hospitalizations and Deaths in Michigan, 1989-1993 (Lansing, Michigan: Michigan Department of Community Health, undated), http://www.michigan.gov/documents/ Childhood_Asthma_6549_7.pdf, R. L. Wahl et al., "Trends in Asthma Mortality and Hospitalization in Detroit, Michigan, 1990-1996," A Public Health Response to Asthma, Atlanta, Centers for Disease Control, February 9-11 1999, Michigan Deparment of Community Health, Epidemiology of Asthma Fact Sheet (Lansing, Michigan: January 2000), http://www.michigan.gov/documents/Asthma_factsheet_6385_7.pdf, Canadian Institute for Health Information, Asthma Hospitalizations Declining, Still Number One Cause of Hospitalizations for Children (September 26, 2001), http://secure.cihi.ca/cihiweb/dispPage.jsp? cw_page=media_26sep2001_e.

[8] D. V. Cohn, "Particles as Well as Ozone Foul Region's Air; Lung Association Report Ranks Areas among Worst in U.S.," Washington Post, April 29, 2004, p. B1

False Claim That Global Warming Will Increase Smog Levels

info@reason.org (Joel Schwartz) — Wed, 04 Aug 2004 00:00:00 EDT

"Heat Advisory," a new report from the Natural Resources Defense Council (NRDC), argues that global warming will cause increases in future ozone smog levels, because warmer temperatures favor ozone formation. NRDC claims that the number of exceedances of the 8-hour ozone standard will increase 60% as a result of global warming.

As Tech Central Station readers well know, there are reasons to be skeptical of claims of substantial human-caused warming. But even taking NRDC's warming estimates at face value, NRDC's smog claim is bogus. As the report itself states:

This research was not intended to provide realistic estimates of future ozone concentrations

NRDC used smog-forming emissions levels from the mid 1990s to predict smog levels in the 2050s and 2080s. But volatile organic compounds (VOC) and nitrogen oxides (NOx), the two smog-forming emissions, have dropped, respectively, at least 50% and 25% just in the last 10 years. So NRDC's modeling estimates don't even apply now, much less 50 or 80 years from now.

Actually, the situation is even worse than that (or better if you're not an environmental activist), because we've already taken actions that will eliminate most remaining smog-forming pollution over the next 20 years or so.

For example, starting in May 2004, EPA's "NOx SIP Call" regulation required a 60% reduction in NOx emissions from coal-fired power plants and industrial boilers during the May-September "ozone season," when compared with previous levels. Data from on-road measurements and vehicle inspection programs show automobile emissions are dropping about 10% per year as the fleet turns over to ever-cleaner models. A fleet meeting EPA standards implemented in the 2004 model year--that is, the fleet that will be on the road in 15 to 20 years--will be 90% cleaner than the current average vehicle. EPA's diesel truck regulation requires a 90% reduction in NOx and soot from diesel beginning in the 2007 model-year, a requirement that will eliminate almost all remaining diesel truck emissions by the 2020s. A similar requirement for off-road diesel equipment comes into effect in 2010. (See details on emissions requirements and their future effects here and here.)

Despite NRDC's admission that the report's smog estimates are not and are not intended to be realistic, the report's Executive Summary is a bit less circumspect:

"Researchers project under a climate change scenario that by mid-century people living in 15 cities in the eastern United States would see a 60 percent increase--from 12 to almost 20 days per summer--in the average number of days exceeding the health-based 8-hour ozone standard."

The press release on the study includes similar claims. NRDC presumably realizes that most journalists will only report this headline, and won't ever get to NRDC's self-refutation buried on page 7. But putting the qualification somewhere in the report gives NRDC plausible deniability when more diligent readers claim the report is deceptive.

Given the actual emissions reductions already achieved, along with future reductions that are already in the pipeline, whatever climate change does occur will make virtually no difference for air quality, because smog-forming emissions will be essentially eliminated long before any significant warming occurs.

Indeed, global warming or not, no claim by environmental activists is more ridiculous than the claim that air pollution will increase in the future. Since 1975, a period during which climate alarmists argue the climate has already significantly warmed, the national-average number of exceedances of the 1-hour ozone standard declined 95% (from 10 to 0.5 days per year), while the number of 8-hour ozone exceedances declined about 60% (from 14 to 6 per year). In other words, if the climate has warmed over the last 30 years, that warming hasn't prevented extraordinary improvements in air quality. (See details on pollution trends here.)

NRDC and the report's authors claim to be motivated by concerns over human health and welfare, but then go on to manufacture fake health risks from smog that won't exist in the future, while ignoring the health and welfare risks of the costs and restrictions they wish to impose on energy production and use. In NRDC's selective view of human welfare, these costs and tradeoffs simply don't exist.

NRDC also cherry picks its climate change impacts. For example, climate change models predict most warming to occur in winter and in northern latitudes, rather than in summer or southern latitudes. Since winter cold has a larger effect on mortality than summer heat, warming would be expected to reduce mortality, but NRDC simply ignores this aspect of health and climate change.

The omissions and fakery of NRDC's report would be bad enough if the report had been produced merely by NRDC's activists. But the report was written by university scientists and medical doctors, including researchers from the Johns Hopkins Bloomberg School of Public Health and Columbia's Mailman School of Public Health, as well as government scientists from NASA's Goddard Institute for Space Studies and the U.S. Department of Agriculture.

Scientists' credibility is rightly diminished when they produce deceptive studies for political activists under the color of their scientific credentials.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

More Highways, Less Pollution

info@reason.org (Joel Schwartz) — Tue, 20 Jul 2004 00:00:00 EDT

Environmental activists continue to mis-diagnose air pollution's causes and cures and to obscure or ignore positive trends in pollution emissions and ambient levels. "Highway Health Hazards," a new report from the Sierra Club, is the latest example.

Of course, all else equal, more driving means more pollution. But the U.S. has achieved large pollution reductions in spite of rapid growth in driving. For example, between 1975 and 2003 total vehicle miles driven increased by more than 110%, but the average number of 8-hour ozone exceedances per year decreased more than 60%, and the average number of 1-hour ozone exceedances per year decreased more than 90%. Average levels of fine airborne particulate matter (PM2.5) decreased more than 40%. Where 60% of the nation's monitoring locations violated the 1-hour ozone standard in the late 1970s, only 10% do so today. All other pollutants declined as well and virtually the entire nation attains federal air standards for carbon monoxide, nitrogen dioxide, and lead.

Technology is winning the war on air pollution by decreasing emissions per vehicle much more rapidly than driving is increasing. Fleet turnover to inherently cleaner vehicles ensures these improvements will continue.

You won't see any of this good news in "Highway Health Hazards." The Sierra Club instead makes the ridiculous claim that "the number of regions with unhealthy air will more than double in the next few years." And despite the fact that automobile emissions per mile are dropping by about 10% per year, while miles driven is increasing only about 2% per year, a heading in the report proclaims "More Highways, More Sprawl, More Pollution." Indeed, the report discusses increases in driving, but provides no data at all on actual trends in vehicle emissions or ambient pollution levels.

While the Sierra Club misleads the public about driving and air pollution, most of "Highway Health Hazards" is devoted to highlighting scary conclusions from cherry-picked air pollution health studies. For example, the report summarizes the American Cancer Society (ACS) study of particulate matter and mortality, which reported an association between higher PM2.5 and risk of death, but omits a study of veterans that found no such link, even though the veterans all had high blood pressure and should therefore have been more susceptible to any PM effects.¹ Also ignored is that fact that even the ACS study found no PM-mortality association for women, those with more than a high school degree, former smokers, and the moderately active -- a biologically implausible collection of results that calls the validity of the entire study into question.

The Sierra Club was also selective about what information it provided from each study it did choose. For example, the Club cites a Denver study that reported that living near busy roads was associated with higher rates of childhood leukemia, but fails to mention that the study was based on cancer incidence data collected from 1976 to 1983 and traffic data from 1990.

Compared to today, the average diesel truck emitted about six times as much soot per mile during the mid-1970s, while the average car emitted about 10 times as much volatile organic compounds (VOC). The Denver study reported that elevated cancer incidence was associated only with living near roads that carry more than 20,000 vehicles per day. So to get an equivalent amount of pollution today, you'd have to live near a road that carries at least six times as much traffic.

The Sierra Club also omits the original study's qualifications of its results. The study was not based on pollution levels, but only on traffic counts. As with all epidemiologic studies, this one is subject to statistical confounding and bias, which could create the appearance of a cause-effect relationship where none actually exists. The study authors noted "Noise, increased light exposure, or some socioeconomic factor may also help explain these results." The study was also based on relatively small samples -- only eight children with leukemia and three controls lived near roads that carried more than 20,000 vehicles per day.

An ironic feature of the Sierra Club's ostensible concern for people's health is that implementing the Club's recommendations would actually increase people's exposure to vehicle pollution. Compared to dense cities, suburbs spread driving out over a wider land area. All else equal, this means lower ambient pollution concentrations for a given total amount of driving. Of course, per-capita driving is lower in denser areas, but not by nearly enough to make up for the increase in density. Thus, despite having greater transit use, denser cities also have more traffic congestion and more concentrated vehicle emissions, as anyone who has walked the streets of Manhattan can attest.

The Sierra Club ignores the inconvenient fact that suburbs and automobile-based lifestyles are not foisted upon the public, but are voluntarily chosen. A recent study by researchers from Harvard and Tufts concluded that suburbanization has indeed improved people's overall welfare, and that as people get wealthier they are more likely to choose suburbs and to drive more. Perhaps people know more about their preferences than the Sierra Club's "experts."

The Sierra Club also doesn't seem to know much about the best ways to reduce air pollution, despite its willingness to propose sweeping and costly reorganizations of Americans' lives in the name of air pollution reduction. A wide range of pollution studies have shown that a small fraction of all cars produces most automobile pollution. For example, based on recent on-road remote sensing measurements the worst 5% of cars produce 50% of automobile VOC emissions, and the worst 10% produce 70%. Thus, policies that aim to decrease overall driving miss the target, since, even if effective, most of the effort and expense would go into reducing miles driven by the vast majority of cars that produce only a few percent of all vehicle pollution.

Land-use and transit are also ineffective as air pollution control measures. Metropolitan areas that plan to increase urban density and spend billions on transit over the next 20 years predict that all this effort will reduce future driving by at most a few percent below "business as usual." Meanwhile, we could reduce total automobile VOC emissions by as much as 40% right now and at a fraction of the cost of transit and growth management, simply by identifying and repairing or scrapping the worst few percent of the vehicle fleet. Furthermore, since the average vehicle on the road will be about 90% cleaner in 15 or 20 years, any long-term efforts to reduce driving will be irrelevant to air pollution by the time they come to fruition.

It's no surprise that the Sierra Club fails to discuss positive air pollution trends and the problems with its policy prescriptions, and ignores people's lifestyle preferences. After all, the Sierra Club's goal is to override people's individual choices and instead bend them to its collectivist vision of how people ought to live -- all for their own good, of course. As Adam Smith aptly put it more than 200 years ago "virtue is more to be feared than vice, because its excesses are not subject to the regulation of conscience."

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

1. A more detailed discussion of PM and mortality can be found here: http://www.cei.org/pdf/3452.pdf.

Toxic Activism

info@reason.org (Joel Schwartz) — Thu, 08 Jul 2004 00:00:00 EDT

According to the latest results from EPA's Toxics Release Inventory toxic releases rose 5 percent in 2002 when compared with the previous year. Environmental activists are practically jubilant, claiming this is the smoking gun showing that the Bush administration has rolled back environmental regulations and stopped enforcing the few that remain.

But reports of the death of environmental regulation are premature. The apparent increase in toxic releases results from emissions reported by a single copper smelter. The facility shut down in 2002, and dismantling it created "waste" required to be reported in the TRI. Excluding that one facility, toxic releases actually declined 3 percent in 2002.

Even if environmentalists were right about the increase in TRI emissions, they might have reflected on the fact that toxic releases increased about 10 percent between 1996 and 1997 on President Clinton's watch. But like the purported uptick in 2002, this factoid has little import for public health. TRI is actually a poor data source for making inferences about the amount of chemicals entering the environment, emission trends over time, or the risks posed to the public. On the other hand, other more comprehensive data show that emissions have been declining and that these declines will continue.

Here's why the TRI doesn't tell us what we need to know:

First, "toxic release" is misleading. Two-thirds of toxic releases in the TRI are not actually released at all, but instead represent solid or liquid waste that is either disposed of on site or by a waste processor, recycled, or burned to produce energy. The 10 percent increase in 1997 becomes a 10 percent decrease when looking only at emissions to air and to surface waters -- a more relevant measure of pollution put into the general environment. By this same measure, toxic releases decreased one percent in 2002.

Second, most chemical releases are not even reported in the TRI. Motor vehicles are not included, nor are businesses that use less than 10,000 pounds of a given chemical. Most non-manufacturing businesses are also not required to report. Some toxic chemicals are not included. For example, power plant emissions of nitrogen oxides and sulfur dioxide exceed all TRI-reported air emissions by a factor of 20, but are not included in TRI reporting.

Third, emissions estimates are notoriously inaccurate, particularly for those that don't come out of a well-defined exhaust pipe. Numerous research studies have revealed serious inaccuracies in EPA's emission inventories, even for the few chemicals that have received substantial scrutiny. The problem is likely to be worse for most TRI chemicals.

In any case, emissions have been declining for those pollution sources that have been carefully measured, including motor vehicles and power plants. Furthermore, during the last 10 years, EPA has imposed "Maximum Achievable Control Technology" standards on dozens of major industries, capping their emissions at 60 to 99 percent below previous levels.

Fourth, even for chemicals emitted into air or water, the TRI has nothing to do with people's actual exposure to potentially harmful chemicals. Many chemicals degrade rapidly in the environment or are diluted to such low concentrations that they are far below a level that could conceivably cause harm.

For example, most people probably know that hydrochloric acid (HCl) can cause serious injury. But as toxicologists like to say, "the dose makes the poison." HCl emissions are so diluted in the environment as to be inconsequential. The very highest ambient levels are 80 percent below EPA's "reference concentration," a safety level set more than 99 percent below the level expected to have deleterious effects, even for chronic exposure. Typical HCl levels range from zero to a small fraction of peak levels.

And although power plants emit large amounts of sulfur dioxide and nitrogen oxides, which aren't even included in TRI, levels of these chemicals in the environment are far below EPA's safety limits and continue to decline.

Fifth, TRI generates huge, scary numbers for the amount of chemicals released each year. Yet, the most common chemicals often pose the least risk, for example, the 600 million pounds of HCl or the 146 million pounds of methanol emitted into the air in 2002. Just these two chemicals alone account for 46 percent of all TRI air emissions. What's important is not total emissions, but the amount and toxicity of the chemicals to which people are actually exposed.

Ambient pollution levels are a far more reliable gauge of both pollution trends and potential chemical exposure. EPA and state regulators monitor many pollutants at dozens to more than a thousand sites around the United States and all types of pollution have steadily declined.

These declines will continue. Despite activist and media claims that the Clean Air Act has been gutted or rolled back, for better or worse traditional command-and-control air quality regulation is alive and well. The Bush administration has for the most part continued the policies of the Clinton administration. Indeed, the Bush EPA recently implemented regulations adopted by the Clinton administration that reduce power plant nitrogen oxides emissions by 60 percent and automobile emissions by 70 to 90 percent. EPA is also implementing regulations that require a 90 percent reduction in diesel truck emissions in 2007 and in off-road diesel equipment in 2010, along with ultra-low-sulfur diesel fuel.

These and other regulations will progressively eliminate almost all remaining air pollution during the next 20 years or so, as the vehicle fleet turns over to cleaner models and as industrial sources continue to install pollution controls. Air pollution has been solved as a long-term problem by actions we've already taken.

Despite the shortcomings of TRI and the realities of air pollution monitoring data and regulatory policy, the latest TRI data prompted the National Environment Trust to proclaim "the era of big government may be over, but the era of toxic pollution is back." NET has it exactly backwards.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

EPA's Make Work Project

info@reason.org (Joel Schwartz) — Thu, 01 Jul 2004 00:00:00 EDT

According to EPA administrator Mike Leavitt, reducing fine particulate matter is "the single most important action we can take to make our air healthier." Leavitt's proclamation accompanied EPA's determination that 243 counties, home to 100 million people, are likely to be designated in November as Clean Air Act "non-attainment" areas for fine particulate matter (PM2.5).

Environmentalists have used EPA's announcement as an opportunity to create the impression that PM2.5 levels are high and that nothing is being done to clean them up. For example, in a Reuters story on the EPA announcement, Vicki Patton of Environmental Defense declared "EPA needs to take swift action to cut the dangerous pollution from power plant smokestacks or millions of Americans will be left gasping for clean air."

Reduce power plant emissions? Done. EPA reduced oxides of nitrogen (NOx) and sulfur dioxide (SO2) from coal-fired power plants by about 30% between 1990 and 2000. The effects of these actions can be seen in the air. Ambient SO2, NOx, and sulfate PM all declined about 30 percent between 1989 and 2002. The Clean Air Act requires an additional 20% reduction in SO2 between 2000 and 2010, while EPA just implemented an additional 60% NOx reduction from coal-fired power plants during the May-September ozone season.

EPA's recently proposed Interstate Air Quality Rule would reduce power plant NOx and SO2 emissions by an additional 65% and 70%, respectively, below current requirements. Despite these reductions, activists and even some media stories continue to claim that power plant pollution has been getting worse.

Millions gasping for air? Hadn't noticed. Particulate levels in the United States are lower than at any time since the industrial revolution. PM has declined more than 80 percent since the early 1900s. PM2.5 is down 40 percent over the last 20 years and 10 percent in just the last four years. If EPA's PM2.5 standard had existed in 1980, about 80% of the nation would have exceeded it. Today, the exceedance rate is down to 18%.

While it's unfortunate that activists continue to misinform and frighten the public with extreme and ridiculous claims, the press deserves the lion's share of the blame for failing to call them on it. Like most media stories on air pollution, today's news items on the EPA PM story reported activists' claims without critical review.

Despite continued reductions in PM2.5, some areas of the country still violate EPA's PM2.5 standard. But exceeding the standard isn't nearly as bad as you might think. First, EPA has two PM2.5 standards-a 24-hour standard for short-term PM2.5 levels and annual-average standard. Virtually the entire nation-99.6% of monitoring sites-already attains the 24-hour standard, in most cases with plenty of room to spare. So non-attainment is limited almost solely to average PM2.5 levels. Second, most areas that exceed the annual standard do so by a small margin. Sixty percent of non-attainment locations could reach attainment with PM2.5 reductions of less than 10%. Another 23% of locations would need reductions of 10% to 20%.

Third, and most important, the health effects of current PM2.5 levels have been greatly exaggerated by EPA and activists. EPA's annual PM2.5 standard is based mainly on the American Cancer Society (ACS) PM study, which reported an association between PM2.5 and mortality. But some odd features of the study suggest that PM is unlikely to be responsible.

According to the ACS results, PM increased mortality in men, but not women; in those with no more than a high school degree, but not those with at least some college; in former-smokers, but not current- or never-smokers; and in those who said they were moderately active, but not the very active or the sedentary. These odd and biologically implausible variations in the ostensible effects of low-level PM suggest that the association between PM and mortality is spurious and doesn't represent a genuine cause-and-effect relationship.

Claims about low-level PM and health suffer from additional biological plausibility problems. Coal-fired power plants contribute about 25 to 50 percent of PM2.5 in the eastern half of the U.S. in form of sulfate formed from SO2 emissions. But toxicology studies with human volunteers suggest that sulfate is not toxic, even at exposures many times greater than even today's peak levels, and even in people with respiratory diseases. Indeed, ammonium sulfate, the main form of sulfate PM, is used as an inert control-that is, a substance not expected to have any health effects-in studies of the health effects of acidic aerosols, while magnesium sulfate is used therapeutically to reduce airway constriction in asthmatics. Likewise, nitrate PM, which makes up about 25 to 50 percent of PM in the western U.S., has also been without health effects in controlled studies.

EPA attributes about 90 percent of the benefits of all air pollution regulation to lives saved due to PM reductions. If PM at current levels isn't killing people, then almost all of the benefits EPA claims for clean-air regulation are bogus. This probably explains why regulators and activists have so staunchly defended PM mortality claims and ignored contrary evidence.

Even the number of people living in areas that violate the PM2.5 standard has been exaggerated. Rather than the 100 million figure reported in news stories, the true value is more like 45 million. The overestimate is due to two factors. First, EPA included many counties not because they violate the PM2.5 standard, but because EPA believes they help cause violations in other counties. This makes sense for regulatory policy, but not for determining PM exposure. Second, counties that monitor PM levels at more than one location sometimes violate the standard in one area, but comply in another, yet EPA counts all people in the county as living in areas that violate the standard. Regardless, most news stories used the 100 million figure in their headlines or first paragraph, with a few adding a qualifier near the end of the story.

Despite the weak evidence of harm from current PM2.5 levels, EPA's PM2.5 non-attainment designations will set in motion a massive Clean Air Act planning and regulation process under which each non-attainment area must develop and implement a State Implementation Plan (SIP) demonstrating attainment of federal PM2.5 standards by between 2010 and 2015. Hundreds and perhaps thousands of people around the country will spend much or all of their time developing, reviewing, and maintaining these plans.

Non-attainment areas will also have to prove to EPA that their regional transportation plans are in "conformity" with their SIPs. That is, they'll have to convince EPA that, say, adding more freeway capacity won't cause an increase in emissions above a level permitted by the SIP. A region that fails the conformity test risks losing its federal transportation funds. SIPs and Transportation Conformity also create many opportunities for the inevitable activist lawsuits that are part and parcel of the Clean Air Act process.

And it is virtually all process. Failing to have an approved SIP or to demonstrate conformity (on paper) carries far worse penalties than failing to actually clean the air. Only the former can result in loss of highway funds and other costly sanctions.

Furthermore, all of this planning is irrelevant to future air quality improvements. The actions necessary to eliminate almost all remaining air pollution have already been taken through regulations for all types of motor vehicles, for power plants, and for industrial facilities.1 PM2.5 will inevitably continue to decline even if we do nothing new.

Rather than a way to reduce pollution, the SIP and conformity processes and the plans, working groups, reports, and regulations that flow from them are mainly a system for maintaining a large cadre of professional regulators and activists and giving them the power to micromanage economic activity and individuals' private choices.

Mr. Leavitt may believe that creating PM2.5 non-attainment areas will improve public health. But EPA's action will merely unleash a new layer of Clean Air Act bureaucracy.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

1. For the details, see "New Source of Confusion," Tech Central Station, August 23, 2003.

State of the Scare, Once Again

info@reason.org (Steven Hayward) info@reason.org (Joel Schwartz) — Mon, 03 May 2004 00:00:00 EDT

The American Lung Association may be the only institution in the country that still gives out failing grades, but you have to hand it to them -- they do it with gusto. "State of the Air 2004" continues ALA's five-year tradition of inflating air pollution levels and health risks in a so-far successful effort to maintain an unwarranted climate of public fear. ALA and other activist groups' tried-and-true strategy stands on three pillars: (1) exaggerate the frequency and extent of high air pollution, (2) take modest, rare, or nonexistent health risks and turn them into serious and pervasive ones, and (3) ignore positive trends and invent negative ones.

ALA's web page asks, "are you one of the 159 million Americans breathing unhealthy air?" That's a big number -- more than half the population. There's just one problem: in many counties, only a small area actually violates the standard. For example, in Los Angeles County, 60% of residents breathe air that passes the 8-hour ozone standard; 95% in Cook County (Chicago); and 99% in San Diego County. Nevertheless, both San Diego and Cook counties earned failing grades from ALA. Indeed, when you base the estimate on actual pollution levels, you find that 97 million people live in areas that violate EPA's 8-hour ozone and/or fine particulate matter (PM2.5) standards. Still a big number (more on that below), but far less than ALA claims.

If you type in your Zip Code, ALA's helpful web site will even tell you the amount of pollution in your area. But for anyone who lives in a county with more than one pollution monitor, the numbers the ALA gives you are virtually always false. We typed in our Zip Codes and checked ALA's claim against the actual EPA data for where we live (Sacramento, CA and McLean, VA, respectively). Downtown Sacramento averaged two days per year exceeding the 8-hour ozone standard during 2000-2002, the years ALA used for its report (and one day during 2003). But ALA claimed 27.2 exceedances per year for downtown Sacramento. Likewise, McLean averaged 5.7 8-hour exceedances per year, but ALA claimed 17.7.

Is ALA just making the numbers up? Not quite, but they might as well be. Here's how ALA pads the results: Most populous counties have more than one ozone monitor, because ozone varies from place to place. For example, in Sacramento County, if ozone exceeds the 8-hour standard one day in Folsom, and the next in Sloughouse, about 15 miles away, ALA counts two days for the entire county, even though nobody experienced more than one. Sacramento County has six ozone monitors, ranging from one to nineteen 8-hour ozone exceedances per year. But it doesn't matter what Sacramento County Zip Code you type in -- you'll always get the same answer, and it will always be greater than the actual ozone levels. "State of the Air, 2004" also includes particulate matter for the first time and uses similar methods to inflate daily PM2.5 levels -- so much so that although only 0.6% of monitoring locations violate EPA's 24-hour PM2.5 standard, ALA somehow managed to squeeze 81 million Americans into that handful of locations.

So even if ALA inflates pollution levels and exaggerates the number of people living in non-attainment areas, 97 million is still a big number, right? It sure would be if that many people were being harmed by air pollution. But they're not, because ALA inflates pollution's health effects too. For example, while ALA claims exceeding 8-hour ozone standard puts most of the population in danger, EPA in 1997 concluded that going from full national attainment of the 1-hour ozone standard to full national attainment of the 8-hour standard would reduce hospital admissions for asthma attacks by 0.6%. Yet the 8-hour standard is much more stringent, with 4.5 times as many sites violating the 8-hour standard as the 1-hour.

And even a report sponsored by a coalition of environmental groups concluded that reducing all U.S. power plant emissions by 75% would reduce respiratory and cardiovascular emergencies by 0.2% to 0.6%.[1] Big pollution reductions, tiny health benefits.[2] And while activists blame air pollution for the doubling of asthma during the last two decades, Figure 1, below, should test the intestinal fortitude of even the most diehard pollution apparatchik. The figure presents national-average trends in air pollution from EPA monitoring data, and the trend in asthma prevalence from the Centers for Disease Control.[3]

Figure 1. Declining Air Pollution, Rising Asthma

Ozone: exceedance days per year
PM: micrograms per cubic meter
CO, NO2, SO2: parts per million
Asthma: rate per thousand population

But isn't any improvement in health, even a fraction of a percent, worth it? It would be if air pollution were the only risk we faced and the pollution reductions were free. In the real world we face many risks and have many aspirations, but have limited resources. In the real world, consumers ultimately pay regulatory costs through higher prices for useful goods and services. More money for pollution control means less money for everything else -- health care, housing, food, leisure, education, as well as other bigger health and safety risks. A regulation will do net good only if it confers benefits greater than the harm from its income-reducing costs.

The public's interest is in an accurate portrayal of risk. This is the only way to make informed choices on air pollution reductions versus other public and private priorities. With the health benefits exaggerated and the costs safely hidden from view, the result has been unnecessarily stringent standards and overinvestment in pollution control. Even the EPA, under President Clinton no less, implicitly reached this conclusion for ozone at least, when it concluded that the social costs of attaining the 8-hour ozone standard would be twice as great as the health benefits achieved (and outside economists believe EPA underestimated the costs of attaining the standard by at least an order of magnitude).

As if the ALA's bleak picture wasn't bad enough already, "State of the Air's" closing section begins "the Clean Air Act is seriously at risk." ALA's focus here is on New Source Review (NSR), which requires new and modified industrial facilities to install technology to meet the "lowest achievable emission rate." Activists, as well as several states' attorneys general and newspaper columnists, continue to claim that the Bush Administration's relaxation of some key NSR provisions amounts to "gutting" the Clean Air Act and will cause millions of tons more pollution emissions each year.

It's not clear how this could happen, because several other pollution reduction requirements remain in force and will eliminate most remaining industrial and vehicle pollution in coming years. Table 1 lists some of the major ones. While "State of the Air" claims power plant pollution will increase, in the real world, EPA's NOx "SIP Call" regulation -- unmentioned by ALA -- will reduce NOx from coal-fired power plants and industrial boilers by 60% just days from now.

Table 1. According to ALA "the Clean Air Act is seriously at risk." You be the judge. Here are EPA's actual regulatory requirements. None of the industry requirements is affected by any changes to New Source Review.[4]

Regulation	Requirement	Effective Date
Clean Air Act Title IV SO2 program	Phase 1 already reduced SO2 emissions from coal-fired power plants by 30% between 1995 and 2000. Phase 2 requires an additional 20% reduction between 2000 and 2010.	Phase 1, 1995 Phase 2, 2000
Clean Air Act Title IV NOx program	26% reduction in NOx emissions from coal-fired power plants between 1997 and 2002.	1997
NOx "SIP Call"	60% reduction in NOx emissions from coal-fired power plants and industrial boilers during May-September "ozone season."	May 2004
Clean Air Act Title III Standards for Hazardous Air Pollutants "HAPs"	More than 70 industry- or process-specific rules already promulgated. All rules require "maximum achievable control technology" (MACT). Reductions are typically 60%-99% for a wide range of substances, including heavy metals, organic chemicals, and particulates.	Various dates from 1994 through the next few years
"Tier 2" automobile emission standards	Decreases allowable NOx and VOC emissions by 70%-80% below "Tier 1" requirement. Extends emissions warranty requirement from 100,000 to 120,000 miles. Requires same low emissions from SUVs and pickups as for cars.	2004 model year and beyond
Heavy-duty diesel truck NOx and smoke standards	90% reduction in NOx and soot below already-implemented 2003 truck standards. 97% reduction in sulfur content of on-road diesel fuel.	2007 model year and beyond
"Tier 4" off-road diesel NOx and smoke standards (proposed rule)	90% reduction in NOx and soot below already-promulgated "Tier 1" through "Tier 3" standards. 97% reduction in sulfur content of off-road diesel fuel.	2010 model year and beyond

Perhaps the greatest failing in the sorry history of "State of the Air" and similar nonsense is not that activist organizations like ALA tell fibs about air pollution, but that journalists don't call them on it. Of course, the two go hand in hand. If the press stopped giving activists a free ride, they might clean up their act, lest they lose public credibility.

But it's even worse than that. With few exceptions, the press routinely aids and abets activists' efforts to make it seem that we've made little progress on air pollution and that the situation is only getting worse. Figure 2 compares typical activist and press quotes on air pollution with actual pollution monitoring data. Although this is the 5th installment of "State of the Air," the Washington Post apparently still hasn't passed the report along to its fact-checking department.

Figure 2. National trend in average number of days per year exceeding the 1-hour ozone standard for all sites that happened to be operating in a given year, and for all sites with continuous data from 1983 to 2003

Fortunately, air pollution affects far fewer people, far less often, and with far less severity than activists or regulators would have us believe. Now that's a story worth telling.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Steven Hayward is resident fellow at American Enterprise Institute.

Endnotes

[1] Abt Associates, The Particulate-Related Health Benefits of Reducing Power Plant Emissions, Prepared for the Clean Air Task Force, Bethesda, Maryland, 2000.

[2] The most serious health claim is that particulate matter at current levels kills tens of thousands of Americans each year. For an in-depth analysis showing why this is implausible see J. Schwartz, Particulate Air Pollution: Weighing the Risks (Competitive Enterprise Institute, April 2003).

[3] CDC changed its survey methods after 1996, so more recent data are not comparable.

[4] For references on these pollution reductions, please refer to "New Source of Confusion."

More Highways, More Pollution?

info@reason.org (Joel Schwartz) — Tue, 16 Mar 2004 00:00:00 EST

According to a new report by the Public Interest Research Group (PIRG) "building new highways will do little to alleviate traffic congestion in the long run and likely will exacerbate already severe air pollution problems in metropolitan areas across the country." PIRG asserts the only solution is to restrict how much people can drive and build more public transit.

The report, "More Highways, More Pollution," is the latest effort by anti-automobile activists to torture the data until it gives the desired confession. In fact, despite a tripling of urban driving during the last 30 years, air pollution has dropped dramatically, while areas that have more freeway lane-miles per capita have lower traffic densities.

Driving and Air Pollution

PIRG claims that building more highway capacity will increase driving and therefore air pollution. But if building highways inevitably increases air pollution, we should have seen a huge increase in air pollution during the last few decades. In fact, just the opposite occurred. While 60 percent of the nation's ozone monitors violated the 1-hour ozone standard in the late 1970s, only 10 percent do so today. Areas with the worst pollution achieved the greatest gains. For example, the San Bernardino area exceeded the 1-hour standard more than 150 times per year in the late 1970s, but only 20 to 30 times per year today.

The nation has likewise made great progress on airborne particulate matter (PM). Only a few percent of the nation's monitoring locations still violate the PM10 standard. About 20 percent violate EPA's new and much more stringent PM_2.5 standard, but PM_2.5 levels have steadily declined, dropping by about 40 percent during the last 25 years. Recent monitoring data show these declines are continuing.

Although at least 90 percent of urban carbon monoxide (CO) emissions come from motor vehicles, more than 99 percent of the U.S. has met the federal carbon monoxide (CO) standard since the early 1990s. The remaining few locations recently came into attainment.

Despite most nitrogen oxides (NOx) coming from motor vehicles, the entire U.S. has been in attainment of the nitrogen dioxide standard for more than a decade. Air toxics have also declined. Although benzene comes mainly from motor vehicles, ambient benzene levels dropped more than 70 percent around the U.S. between 1989 and 1999.

Highways and Air Pollution

PIRG reports that total miles driven in urban areas tripled between 1970 and 2002. Thus, America achieved extraordinary air pollution reductions despite vast increases in driving. These facts are lost on PIRG, which ignores past pollution trends and claims pollution is "severe" and getting worse. In PIRG's imaginary world "The experience of the last 30 years has shown that limits on tailpipe emissions -- while necessary -- are not enough to resolve the problem of vehicular air pollution. Any strategy to reduce health threats from air pollution must include a strategy to curtail the growth of vehicle travel."

Ironically, even PIRG's own numbers don't support its conclusions. For example, PIRG notes that "Vehicles are 80 to 99 percent cleaner per mile than vehicles produced in the late 1960s" (emphasis in original). Let's assume then that per-mile emissions of the average vehicle declined 90 percent since the late 1960s -- the middle of PIRG's range. If driving hadn't increased, this would have led to a 90 percent decrease in total emissions. Or put another way, if emissions equaled 1.0 in 1969, they would equal 0.1 today. Now let's add a factor of three increase in driving: 0.1 * 3 = 0.3. In other words, even with a tripling of driving, technological improvements in vehicle emissions control reduced total emissions by 70 percent.

On-road measurements show vehicle emissions are dropping about 10 percent per year due to fleet turnover. Driving is increasing only about one to 3 percent per year, for a net decline in emissions of 7 to 9 percent per year. Because more-recent vehicle models continue to start out and stay cleaner than earlier models, fleet turnover will continue to clean the air. New SUVs have been as clean as new cars for the last several years, so the popularity of larger vehicles won't affect future air quality. EPA regulations that phase in during the next few years require an additional 70 to 90 percent reduction in new-vehicle emissions from both cars and diesel trucks, ensuring that most remaining motor-vehicle pollution will be eliminated during the next 20 years or so. PIRG's fanciful claims not withstanding, technology will continue to win the battle against air pollution without the need to restrict people's travel choices.

Highways and Congestion

PIRG believes that building highways "induces" more demand for travel, eliminating any gains from extra road capacity. If people had an infinite demand for automobile travel this might be the case. But in the real world, cities with more highway lane-miles per capita actually have lower traffic densities, as shown in Figure 1.

Figure 1. Relationship between Driving and Highway Miles

Notes: Analysis by Wendell Cox, based on 1999 data from the Texas Transportation Institute for urbanized areas with more than 1 million population. Each point represents an urbanized area. Slope is statistically significant at the 99.9% level.

As transportation researcher Randal O'Toole puts it, "travel that is 'induced' by added capacity is actually travel that had been repressed or shifted by capacity shortages."[1] Between 1980 to 2000 the number of cars in the U.S. increased 50 percent, while total miles driven increased 75 percent. Yet the number of road miles increased by only about 5 percent. Recent increases in congestion aren't due to building more freeways, but are "due to more driving without a similar increase in freeways."[2]

Most Americans consider the unparalleled convenience and flexibility of the automobile to be a great benefit. Even with increasing congestion due to lagging road investments, most Americans still prefer driving to other modes of transportation. PIRG wishes it were otherwise, but getting people to use transit is no easy task. Metropolitan planning organizations, the regional agencies that draft metropolitan transportation plans, predict that even spending thousands of dollars per capita on new urban transit services -- hundreds of billions on a nationwide basis -- would at most reduce single-occupant-vehicle trips by a few percent below "business as usual." And the urban densities required to make transit viable will increase congestion, because per-capita driving decreases only modestly with increasing density.

Instead of providing infrastructure for the types of transportation Americans most desire, PIRG instead aims to end highway building and increase transit. Where the vast majority of Americans see great net benefits to automobile travel, PIRG sees only costs. Rather than pursue the "public interest," PIRG seeks to override Americans' preferences.

False Premises

PIRG's staff carefully chose and structured the data to tell the story they wanted. But even here they didn't do a very good job. PIRG used EPA's official inventory of VOC and NOx emissions for its estimates. However, these inventories have never passed a real-world validation test. For example, PIRG claims, based on EPA estimates, that 29 percent of volatile organic compound (VOC) emissions come from on-road vehicles. But real-world studies in several cities show the actual contribution ranges from about 50 to 85 percent. PIRG could have bolstered its anti-automobile case if its staff were familiar with basic air pollution science.

Indeed, PIRG didn't even bother to check its central claim that per-capita pollution emissions correlate with ambient pollution levels. They don't. As shown in Figure 2, there is no correlation between PIRG's estimate of emissions per capita and actual measured ozone levels. Several factors could explain this. First, PIRG naively used EPA's incorrect emissions inventory. Second, pollution levels vary based on differences in weather from place to place. Third, urban form affects pollution levels. Higher population density means more emissions per unit area. Suburbanization might increase driving, but it reduces the density of emissions much more. Ambient pollution levels are what matter for health. If higher per-capita emissions don't translate into higher ambient pollution levels, then PIRG's entire study is based on a false premise.

Figure 2. PIRG's Estimate of Per-Capita Motor Vehicle Emissions vs. Ozone Levels

Notes: Each point represents a single metropolitan statistical area (MSA). "NOx + VOC per capita" is for 1999 and is from the PIRG report. All MSA's with more than 1 million population are included. "Ozone exceedances" is the number of 8-hour ozone exceedances in 1999 at the worst location in each MSA. Ozone data were downloaded from EPA here.

Most people prefer auto-based lifestyles, and technology and fleet turnover are mitigating air pollution. Instead of trying to make motorists miserable, scarce transportation dollars should instead be allocated to reflect the actual relative demand for transit and auto travel. That would allow cities to provide the additional automobile infrastructure necessary to keep up with travel demand, reduce road congestion, and provide a transportation system that meets people's needs.

PIRG's report should provide grist for courses in critical thinking, but shouldn't be taken seriously as a guide for policymakers.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

[1] R. O'Toole, The Vanishing Automobile, and Other Urban Myths (Bandon, OR: Thoreau Institute, 2001).

[2] Ibid.

Smart Growth Increases Pollution Woes

info@reason.org (Joel Schwartz) info@reason.org (Wendell Cox) — Sun, 10 Aug 2003 00:00:00 EDT

A recent special report in The Californian argued that urban sprawl represents the greatest threat to the valley's air quality, and that "Smart Growth" urban planning would reduce the road congestion and air pollution caused by suburban development.

But that's misdiagnosing the problem and prescribing dangerous medicine. Technology is improving air quality more rapidly, effectively, and cheaply than can urban planning. Misnamed smart growth would actually increase gridlock and smog, while putting home ownership out of reach for more Kern County residents.

Smart growth packs more cars and more emissions into a given land area, increasing both congestion and air pollution. Average work commute times are actually highest in the densest cities.

Fortunately, technology is breaking the link between air pollution and driving. Vehicles built to current Air Resources Board requirements will be more than 90 percent cleaner over their lifetimes when compared with the average car now on the road. Thus, even if the valley's population doubles during the next 25 years, total automobile emissions will decline at least 80 percent as the fleet turns over to these 21st century vehicles.

While technology rapidly reduces valley emissions, smart growth plans will be busy raising home prices. People across the state move to the valley because it is one of the last bastions of affordable housing in California. But research shows that urban growth limits and similar smart growth measures drive up housing prices. In the Bay area, San Jose's smart growth policies helped drive up home prices an astronomical 936 percent from 1976 to 2001. And Portland, Ore., a smart growth pioneer, quickly went from being one of the most affordable to one of the least affordable cities.

Smart growth plans pack people into high-density neighborhoods. But is that what consumers and home buyers want? Developers don't force consumers to choose "sprawl" against their will. In a dynamic and competitive housing market, developers have a tremendous incentive to find out what combination of amenities will most appeal to home buyers. If people were clamoring to live in high-rise apartments or condos, developers would build them. Right now, most people, especially those in Bakersfield and the valley, want single-family homes with a bit of land in the front and back yard.

We use to call this the American Dream. Now wanting to own a home with a yard is called sprawl and is bad for us?

People should be free to choose the lifestyles they desire -- whether sprawling suburbs or high-density "mixed-use" neighborhoods and should bear the costs for their decisions. And they do. New-home buyers generally pay in the sale price for all of the road, sewer and water infrastructure for direct service to their property.

Smart growth is a dumb choice unless we want higher housing prices. Bakersfield's air quality is going to be improved by technology and getting high-polluting cars off the road, not by building high-density housing projects.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Wendell Cox is a transportation and demographics consultant and spent three terms on the Los Angeles County Transportation Commission.

Clearing the Air

info@reason.org (Joel Schwartz) — Tue, 01 Jul 2003 14:44:00 EDT

...

Reducing California's Petroleum Dependence

info@reason.org (Joel Schwartz) info@reason.org (Lynne Kiesling) — Tue, 10 Jun 2003 00:00:00 EDT

A. Introduction and Summary

The CEC/CARB AB 2076 Report (hereafter "the Report") recommends that California set goals of reducing petroleum consumption to 15% below the 2000 level by 2020, and increasing the market share of alternative fuels to 15% of demand by 2020. The Report recommends achieving these goals by mandating a doubling of average automobile fuel economy and requiring that a minimum percentage of on-road transportation fuel be derived from non-petroleum sources.

The Report asserts that reducing petroleum use is necessary to mitigate the following problems:

High and volatile gasoline prices
High security costs for protecting middle east oil supplies
Inability to refine enough petroleum in California to meet California's demand
Mitigating environmental problems such as climate change and air pollution

The Report's cost benefit analysis concludes that mandating substantial increases in vehicle fuel economy would result in billions to tens of billions of dollars in net benefits to California's citizens over the next 30 years. On the other hand, the Report concludes that mandating alternative fuel use would result in billions of dollars in net costs to California's citizens.

We have grave concerns over the Report's assumptions about the nature of the problems, what problems are in need of policy solutions, the assumptions of the cost-benefit analyses, and the recommended solutions themselves. We summarize our concerns below and discuss them in greater detail in the rest of this comment letter.

Mandating fuel efficiency improvements will impose net costs on motorists. About 70% of the benefits claimed for fuel efficiency improvements are direct benefits to motorists in the form of savings in gasoline costs. But motorists can already purchase any of a few dozen vehicle models that get more than 30 miles per gallon (mpg), and yet, on average, they choose vehicles that get a bit more than 20 miles per gallon. Motorists are aware of the level and volatility of gasoline prices and no doubt take this into account in their purchase decisions. This suggests that whatever costs and benefits the Report counts in its cost-benefit analysis, they have little to do with motorists' actual valuation of greater fuel economy vis-à-vis other automobile amenities. When automakers can offer high-mileage vehicles with a palatable combination of price and other desired amenities, motorists will choose them without any external prodding. This suggests that mandating fuel efficiency increases will impose net costs on Americans. Therefore, rather than benefiting Californians, implementing the Report's recommendations would likely make people worse off.

Reducing petroleum consumption would not reduce oil security costs. The level of U.S. expenditures to protect middle east oil supplies is a matter of debate in the research literature. But whatever the costs are, marginal reductions in petroleum use won't reduce these costs. The level of military effort that policymakers judge to be necessary to protect the oil supply and meet other U.S. geopolitical interests is likely to be independent of oil consumption over a wide range of oil consumption levels. A 15% reduction in California or even U.S. oil consumption would probably have no effect on such decisions. The estimated benefits due to decreased oil security costs should be removed from the Report's cost benefit analysis.

Implementing the Report's recommendations would worsen future air quality. Existing CARB LEV II requirements will eliminate more than 90% of current vehicle emissions during the next 20 years or so, leaving little marginal benefit to be had through additional measures. Yet by making new cars more expensive, implementing the Report's recommendations will slow the rate of new-car purchases, which would in turn slow progress on air pollution by slowing vehicle-fleet turnover.

Internalizing the environmental cost of CO₂ emissions would not change motorist behavior. The Report estimates the harm from CO₂ emissions to be $15/ton, which is equivalent to about 15 ¢/gallon. These costs could be internalized through a gasoline tax, but such a tax is probably too small to change motorists driving behavior or vehicle-purchase decisions. If internalizing the cost of CO₂ emissions wouldn't appreciably change motorists' behavior, then requiring CO₂ reductions is almost guaranteed to impose net costs on society.

The Report assumes a static petroleum market. The Report assumes no changes in the petroleum market between now and 2030. But the petroleum market is dynamic. New oil development in Russia, the Caspian Sea, and West Africa, along with ongoing reductions in oil exploration and recovery costs, are reducing OPEC's ability to control petroleum supplies. These trends will tend to reduce both the future cost and volatility of petroleum.

The Report ignores government-mandated balkanization of fuel markets as a source of gasoline-price volatility. Some and perhaps much of the volatility in gasoline prices is due to regulatory requirements on fuel composition that vary from place to place. Despite this factor being under the complete control of state and federal policymakers, the Report does not address reforming reformulated-fuel requirements as a means of reducing price volatility.

Importing gasoline from out-of-state refineries is not a problem. The Report notes that California doesn't have enough in-state refining capacity to meet its future fuel needs and dubs this a problem. This is no more a problem than the fact that Los Angeles is a net importer of food. Gasoline producers will efficiently respond to consumer demand if allowed to do so.

Governments have a poor record in picking technology winners. The Report implicitly assumes that government can pick technology and alternative fuel "winners." Political manipulation of funding choices, the need for decentralized experimentation to determine optimal approaches, the rapid evolution of technologies and processes, and the market discipline of prices and consumer preferences to drive determinations of what's worth doing, all ensure that even the best intentioned central planners will do a poor job of picking the "right" approaches. The approaches that will bring net benefits to Californians are unknown and are most likely to be realized through a decentralized, market-based discovery process.

The Report recommends mandating alternative fuels even though its own analysis indicates this would impose billions in net costs. If after considering all costs and benefits of a policy one finds a net cost, then, by definition, implementing the policy will make people worse off. Rather than make California's economy more resilient, implementing the Report's recommendation would make the state's economy more brittle by requiring consumers and businesses to adopt an energy portfolio that they would not choose on their own due to its great costs. The extra energy costs would draw resources away from other productive activities and investments, reducing the resilience of households and businesses.

Summary. Overall, the Report suffers from an errant definition of the problems that need to be solved, and claims benefits for its recommended policies that would not actually materialize. Indeed, implementing the Report's recommendations would cause net harm to California's citizens. The Report's problem definitions and cost-benefit analyses require major rethinking and revision before the Report can be considered as a sound basis for fashioning energy policy in California.

B. The Report's Cost-Benefit Analysis of Fuel-Efficiency Improvements Is Inconsistent with Motorists' Actual Assessments of Costs and Benefits

In the energy efficiency scenarios, the Report estimates that cumulative net benefits from 2002-2030 of tens billions would result from implementing the Report's recommendation for a mandated doubling of average vehicle fuel economy. But the Report's analysis doesn't appear to have real-world validity.

About 70% of the benefits claimed for reducing petroleum use come from direct savings to motorists, who would spend less to purchase fuel if their cars were more fuel efficient. But motorists already have the opportunity to purchase any of a few dozen models that get more than 30 miles per gallon (mpg), yet they choose not to do so. On average, motorists choose cars that get a little over 21 mpg. This "revealed preference" shows that, on balance, motorists value the additional amenities of low-mpg vehicles more than the extra cost of the gasoline they consume. Indeed, motorists have continued to purchase low-mpg vehicles even during the last few years of relatively high and volatile oil prices.

Motorists have told us through their purchasing decisions that, all things considered, low-mpg vehicles provide a better combination of price and amenities than high-mpg vehicles. This suggests that the Report's analysis of the net benefits of raising fuel-efficiency requirements makes false assumptions about what motorists most value, and that raising fuel efficiency requirements would actually result in net costs to California's citizens.

One might argue that technological advances will reduce the cost of improved fuel economy in the future, which will improve the cost-benefit picture. We agree that this is very likely. But that is still not an argument to require improved fuel economy. Motorists will buy high-mpg vehicles without any prompting as soon as automakers can deliver high fuel efficiency in combination with the other amenities that most motorists desire and at a palatable cost.

Indeed, the argument for mandating greater fuel efficiency rests on a logical fallacy. The call for a government mandate is predicated on the assumption that automakers are purposely withholding fuel-efficient technologies that consumers would buy if they were offered. Yet such a claim implicitly assumes that profit-seeking automakers are foolishly refusing to offer products that would help them sell more vehicles and thereby gain market share. To avoid a logical contradiction, we would have to assume that regulators and environmental activists know more about how to please motorists and make auto companies more profitable than the managers, board members, and shareholders of those companies—a highly dubious proposition.

Another argument for requiring greater fuel efficiency is based on the external costs of automobile use that are not included in the purchase price of the vehicle or the cost of gasoline. But to the extent these costs are real, the appropriate way to deal with them is by adding them to the price of fuel and/or vehicles. But this approach would probably do little to increase demand for more fuel efficient vehicles, because the marginal increase in the cost of driving would be small.

For example, using CEC's estimate of $15/ton for the environmental costs imposed by CO₂ emissions, internalizing this cost would add 15 ¢/gallon to the cost of gasoline. Adding in the Report's assumption of 12 ¢/gallon for oil security costs would bring the total tax to 27 ¢/gallon. Assuming an average vehicle life of 120,000 miles, doubling average vehicle fuel economy from about 21 mpg to about 42 mpg would amount to an incremental savings in lifetime vehicle costs of only about $700, or about $60 per year. While this isn't a trivial amount of money, it is probably too small to have much effect on vehicle purchasing decisions or driving behavior. This analysis amplifies the concern about whether mandated fuel economy increases confer net benefits. If internalizing external costs of fuel use wouldn't cause much of a change in motorist behavior, then the Report must be wrong in concluding that mandating large increases in fuel economy would confer net benefits.

Frequent, painful experience keeps motorists acutely aware of both the price and price volatility of gasoline. The average motorist's refusal to purchase high-mpg vehicles is not due to lack of knowledge of benefits. Rather, on balance, the claimed benefits of high-mpg vehicles simply don't exist yet. Motorists find low-mpg vehicles to be a better overall value. When the price-amenity equation changes, as it surely will, motorists will choose high-mpg vehicles of their own free will and the result will be net societal benefits. Mandating higher fuel efficiency would only make motorists worse off.

C. Fuel Regulations Balkanize Markets and Increase Price Volatility

Some and perhaps much of the volatility in gasoline prices is due to regulatory requirements on fuel composition that vary from place to place. In particular, California's reformulated gasoline limits flexibility in the gasoline market by making non-California gasoline less substitutable for California's reformulated gasoline. Likewise, the federal government requires the addition of oxygenates, a requirement which can now practically be met only with ethanol. This balkanization of fuel markets enables price spikes to occur and to persist. Despite these factors being under the complete control of state and federal policymakers, the Report does not address reforming reformulated-fuel requirements as a means of reducing price volatility.

CEC and CARB should commission an independent analysis of the effect of fuel regulations on gasoline-price volatility, and examine opportunities for more flexible regulations that would maintain air quality benefits while reducing the potential for supply disruptions and ensuing price spikes.

D. World Petroleum Markets Are Dynamic, but the Report Assumes A Static Market

The Report is founded on a static view of petroleum markets, one that assumes little or no change in the global oil industry over the decades covered in the analysis. In particular, likely changes in world oil markets over the next 20 years are assumed away. For example, the report ignores the development and capital investment in Russia, around the Caspian Sea, and in West Africa, as well as continually declining costs for oil exploration and recovery. As a result, almost all of the growth in oil production is occurring in non-OPEC countries. This growth reduces OPEC's market power, and threatens to reduce its market share, reducing its ability to control supply and prices.

Another important dynamic aspect of energy markets is the use of financial instruments and contracts to reduce risk and, consequently, to reduce price volatility beyond what it otherwise would have been. The report never addresses the role that financial markets (hedging, derivatives, etc.) play in reducing fuel price volatility, without the need for additional government action, regulation, or planning.

At the very least the Report should incorporate scenario analyses based on different world oil market contexts, as a test of how robust its conclusions are to the dynamics of the ever-changing global oil market.

E. Governments Have A Poor Record in Trying to Pick Technology "Winners"

In discussing the move away from petroleum-based fuels to fuel cells, the Report implicitly assumes that the government policymakers can pick technology winners, and that it can control both the rate and outcome of technology and process innovation. Governments (and corporate bureaucracies, for that matter) have a very poor track record of picking technology winners, and we have little reason to believe that the success rate in this case will be any different.

The most dramatic example of government subsidies to unsuccessful commercialization research is federal subsidies to solar thermal research during the late 1970s. In the wake of the energy crisis of the 1970s, Congress and the Carter Administration approved a large budget increase for research into thermal solar technology. Five years and massive amounts of research did not yield a commercially viable competing technology to the old photovoltaic solar cells, the technology of which had of course also advanced.

In the case of hydrogen generation, storage, and transport, fuel cells, fueling infrastructure, and so on, there are several competing technologies all innovating simultaneously. We do not know which one in each area is the most commercializable, and even if we could somehow generate a sound current ranking, a sudden discovery in one technology could upend that ranking in an instant. Technological developments in other areas could even reduce interest in fuel cells. Government-guided research runs the risk of choosing the wrong technologies.

If the government attempts to pick winners through targeted subsidies and picks wrong, then we are stuck with that bad, costly mistake. This mistake could become particularly costly once, for example, companies start building, hydrogen fueling stations, investing in a lot of fixed infrastructure in special purpose assets if it turns out that the most commercially viable way to deliver the hydrogen is not compatible with those specific assets. Such a costly policy error would lead to significant wasted investment, and if subsidized, a lot of wasted taxpayer money.

Private markets are a superior way to make decisions about technologies and funding levels. Investors use market processes to deal with such unknowns by holding diversified portfolios of venture capital. Venture capital firms do not typically sink all of their resources into one technology that they believe has the highest probability of winning – they hedge that investment by investing in other technologies, in other industries. They want to maximize their risk-adjusted profit, knowing full well that some research will result in new technologies that deliver new and/or improved benefits at lower costs to consumers, and some will not. Such a portfolio approach is a hedge against the pervasive inability to pick winners. Experience with government research suggests that its track record does not improve upon the private investment portfolio approach.

One of the arguments in favor of targeted government technology research subsidies is that such subsidies will reduce unnecessary duplication of research efforts. If there is duplication of research, that means that there is plenty of private-sector interest in the topic, so increasing government subsidies will only serve to crowd out that private investment in research that would have happened anyway. Why spend taxpayer money that way when private investors are willing to incur research costs?

One typical answer to that question is that duplicative research efforts are a wasteful dissipation of resources in the race to be "first to the finish line." That argument ignores the benefits of duplicative research. If you try to channel these efforts and guide research with an objective of minimizing duplication, you are very likely to fail, because the duplication is never perfect—even if several people are working toward the same goal, such as smaller or cheaper fuel cells, the variations in their procedures, materials, ways of approaching the problem, and just sheer luck will all lead them down different paths. This decentralized discovery process maximizes the potential benefits from research. All of that seeming duplication is not duplication at all. Instead, it maximizes the probability that someone will come up with technologies and processes of greater benefit to society. And the fact that the search is decentralized and diverse means that society doesn't have all its eggs in one basket.

Government research subsidies and those who argue for them also tend to overlook a very important part of the technology diffusion process: consumer demand. Technologies that do not meet consumer needs for practicality, convenience, carrying capacity, power, and aesthetics will fail, regardless of their scientific virtuosity or cost-effectiveness. Failure to take into account consumer demand further inhibits the ability of government to pick winners, and also points up another major difference between private investment processes and government subsidy processes.

The Report ignores the preferences of consumers, which is how it was able to manufacture benefits from mandated fuel-efficiency requirements. The costs used in the cost-benefit analysis do not include the changes to vehicles that would have to occur to make the increased fuel efficiency happen: decreased power, decreased torque, decreased size, and possibly decreased safety. These features matter to consumers, and government dictation of the features that peoples' vehicles will have would likely make consumers worse off.

It is important to remember that technological change is incremental and evolutionary, and that important features, processes and technologies can be very different from what one might have expected at the beginning of a research program. Predicting what will succeed and what will be a dead end is difficult, so any policy decisions that steer research into bureaucratically determined paths could do more harm than good.

F. Mandating Alternative Fuels will Harm Californians

Despite finding that requiring alternative fuels would cause billions of dollars in net harm to Californians, the Report recommends a mandated minimum market share of 15% for alternative fuels. The Report's rationale is that it will make California's economy more resilient. But this is a non-sequitur. If after considering all costs and benefits of a policy one finds a net cost, then, by definition, implementing the policy will make people worse off overall. Indeed, the Report's recommendation for an alternative fuels mandate is in effect an argument that we should shoot ourselves in the foot now in order to avoid the risk that we might get shot in the foot later.

Rather than make California's economy more resilient, implementing the Report's recommendation would make the state's economy more brittle by requiring consumers and businesses to adopt an energy portfolio that no one would choose on their own due to its great cost and risk. The extra energy costs would draw resources away from other productive activities and investments, reducing the resilience of households and businesses. The recommendation for an alternative fuels mandate should be removed from the report.

G. Environmental Problems

The Report identifies two major environmental problems—air pollution and global warming, which we take up in turn.

1. Air Pollution

Increasing petroleum use is not an obstacle to improved air quality

The Report states "Increasing our reliance on petroleum would…be an obstacle to improved air quality." This statement is simply false. According to the Report, gasoline consumption rose 50% in California between 1980 and 2002, yet this was a period of extraordinary improvement in California's air quality. During the 1980s, the San Bernardino area, with the worst ozone levels in the nation, exceeded the federal 1-hour ozone standard about 140 times per year. Today, Crestline—the worst location—is down to about 25 exceedances per year, while San Bernardino and Redlands average around 10 to 20. Half the population of South Coast now lives in areas that meet both the 1-hour and 8-hour ozone standards, while about 99 percent of people in the Bay Area and San Diego likewise live in areas meeting both ozone standards. Figure 1 displays the trend in 1-hour ozone exceedances at the worst monitoring location in each of California's major air basins.

Levels of all other pollutants have likewise declined substantially during the last 20 to 30 years. The vast majority of monitoring locations now comply with federal PM10 standards, and the entire state complies with standards for CO, NOx and sulfur dioxide.

Figure 1. Trend in 1-hour Ozone Exceedances at Worst Location in Each Air Basin

Source: CARB monitoring data

These declines will continue, regardless of VMT growth. Tunnel studies show that fleet-average light-duty-vehicle HC emissions in California are declining about 15% per year, while NOx is declining about 9% per year (see Figure 2). Given that VMT is increasing about 1.8% per year, this results in a net annual decline HC and NOx of 13% and 7% respectively. These trends will only continue. A fleet meeting CARB's LEV II requirements for gasoline vehicles would emit more than 90% less HC and NOx per mile of travel than the fleet currently on the road. The fleet will turn over to these vehicles during the next 20 years or so. VMT increases will have little effect on future emissions, given these large per-mile emission reductions. For example, if per-mile emissions decline 90% and VMT increases 50%, total emissions would still decline by 85%.

Thus, the long run problem of air pollution from automobiles has already been solved by existing requirements that will come to fruition during the next 20 years or so. But we still have a near-term air pollution problem. This problem would be most quickly and cheaply resolved through repair or scrappage of high-emitting vehicles. A small percentage of vehicles contributes most fleet emissions (see Figure 3). For example, remote sensing data collected in Riverside, California in 2001 show that the worst 5% of HC emitters account for more than 50% of tailpipe HC emissions. As the chart shows, the vast majority of vehicles have very low emissions, while a few have very high emissions and account for most pollution from the fleet.

This means that most vehicle emissions are not due to petroleum consumption per se, but to the small percentage of vehicles with broken emission control systems. To solve this problem, we should focus on measures to identify and either repair or scrap these high emitters. This is also only a near-term problem, as these older high emitters are slowly but surely being replaced by more recent models that stay cleaner throughout their lives.

Figure 2. Trend in Fleet-Average Emissions of California Light-Duty Vehicles, 1994-2001

Source: A. J. Kean et al., "Trends in Exhaust Emissions from In-Use California Light-Duty Vehicles, 1994-2001," (Society of Automotive Engineers, 2002).

Figure 3. VOC Emissions Distribution of Vehicles Measured by Remote Sensing in Riverside, California in 2001

HC emissions from 1,207 vehicles with 2 or more measurements, ranked from cleanest to dirtiest. Emissions are in grams of VOC emitted per gallon of fuel burned. Negative HC readings represent "real" noise in the data. Data were collected in Riverside, California in 2001 by Gary Bishop of the University of Denver. Data were downloaded from www.feat.biochem.du.edu/light_duty_vehicles.html. These vehicles are 15 years old on average, and 75 percent are at least 12 years old.

Air Pollution Reductions Beyond Current Requirements would Result in Little or No Marginal Benefit. Because current air pollution problems are being solved by existing measures, there is little or no marginal benefit to additional pollution reductions over and above those that will occur due to existing LEV II and other vehicle emission requirements. The Report implicitly acknowledges this, as its estimated air quality benefits from reduced petroleum consumption amount to about 50 cents per person per year, or one percent of all estimated benefits. These presumed benefits are also due to pollution reductions from a baseline pollution level that is already below the limits set by federal and California health standards.

Implementing the Report's Recommendations would Make Future Air Quality Worse than it Would Otherwise Be. Implementing the Report's recommendations would make new cars more expensive. As a result, people would buy fewer new cars and would hold on to existing cars longer. Since fleet turnover is the most important factor for air quality improvements, implementing the Report's recommendations would make future air quality worse than it would otherwise be. Rather than counting air pollution benefits in its cost-benefit analysis, the Report should actually conclude that implementing its recommendations would impose air quality costs.

The Report Overestimates the Health Improvements from Air Pollution Reductions. Even the small amount of health benefits attributed to additional air pollution reductions are overstated. Most of the claimed benefits are due to projected reductions in mortality due to reductions in particulate matter (PM). The Report bases its PM mortality estimate on the Health Effects Institute's (HEI) Reanalysis of the American Cancer Society (ACS) study of PM and mortality. However, residual confounding in this study makes it likely that the results are spurious. For example, the HEI/ACS study reported that PM increased mortality for men, but not women; for those with no more than a high school degree, but not those with at least some college education; for those who said they were moderately active, but not those who said they were either sedentary or very active; and for former smokers, but not current or never smokers. These results are biologically implausible and suggest that residual confounding accounts for them. The report also found no increase in mortality due to respiratory causes specifically, which is surprising given that air pollution would be expected to exert its effects through the respiratory system.

At the very least, taking the HEI/ACS results at face value, only the 25% of the population that is male and has no more than a high school degree would be expected to suffer increased mortality. The Report also ignores the results of a recent epidemiologic cohort study of veterans with high blood pressure that found no relationship between PM levels and mortality, despite that this group was expected to be particularly susceptible to air pollution's effects. These results indicate that the Report's benefit estimates for air pollution reductions are greatly overstated.

Summary. Air quality in 10 or 20 years will be far better than it is today, regardless of California's policy on petroleum consumption. Furthermore, virtually none of the purported benefits of reduced petroleum consumption are due to air quality improvements. Thus, it is at best terribly misleading for the Report to either raise alarms about future air quality, or to suggest that reduced petroleum consumption is a sensible policy for air quality improvement, when other policies would provide greater and more rapid pollution reductions and would do so without the harm that would be caused by mandated fuel efficiency improvements or mandated alternative fuel usage.

Instead, the Report should state prominently that (1) air quality is improving and will continue to improve regardless of California's petroleum consumption trends, (2) mandating higher fuel economy would slow fleet turnover by making new vehicles more expensive, thereby making future air quality worse than it would otherwise be, (3) existing requirements will eliminate almost all remaining automobile air pollution during the next 20 years or so, and (4) near-term air pollution improvement would be most quickly and cheaply achieved through repair or scrappage of high-emitting vehicles.

2. Climate change

Climate change is an analytically complex issue, and forecasts of future climate change and attendant costs are fraught with uncertainties. A detailed discussion is beyond the scope of these comments. However, even taking the Report's damage estimates from CO₂ emissions at face value, eliminating the CO₂ emissions would cost more than the estimated harm caused by the emissions. This alone guarantees that CO₂ reductions will cause net harm. A simple analysis shows why this is the case.

The Report estimates the harm from CO₂ emissions to be $15/ton, which is equivalent to about 15 ¢/gallon. These costs could be internalized through a gasoline tax, but such a tax is probably too small to change motorists driving behavior or vehicle-purchase decisions. For example, buying a 42 mpg vehicle instead of a 21 mpg vehicle would save only about $35 per year in CO₂ taxes. This means that even charging motorists the full estimated cost of all of their CO₂ emissions would likely cause hardly any reduction in CO₂ emissions. If internalizing the cost of CO₂ emissions wouldn't appreciably change motorists' behavior, then requiring CO₂ reductions is almost guaranteed to impose net costs on society.

The Report also notes "Our estimate of $15 per ton of CO₂ equivalent seems reasonable if cost of control or current market trades are any indication. $15/ton is also consistent with the finding of Friedrich and Bickel that damage estimates currently are lower than cost of control or market trades." If the damage done by a ton of CO₂ emissions is less than the cost of reducing those emissions, then reducing the emissions will cause net harm.

H. Oil Supply Risk: Marginal Reductions in Petroleum Consumption will Not Reduce Military or other Expenditures to Protect Foreign Oil Supplies

The Report includes benefits from reduced oil security costs as part of the estimated benefits of reduced petroleum consumption. As the Report notes, there is little agreement in the research literature over just what those costs are. However, whatever the costs are, the reduction in oil security costs due to marginal reductions in petroleum consumption is likely to be zero. This is because the nature and extent of U.S. military activity to protect U.S. interests in the middle east are not elastic with oil consumption. Instead, such missions depend on a range of interacting geopolitical factors of which oil is only one.

Furthermore, the level of military effort judged to be necessary is likely to be independent of oil consumption over a wide range of oil consumption levels. After all, regardless of whether the U.S. imports 20% or 30% of its oil from the middle east, the military effort necessary to ensure its availability would likely be the same. Even if the U.S. imported hardly any of its oil from the middle east, the U.S. might consider it strategically important to protect middle east oil anyway, since many of its allies would import much their oil from the middle east.

The Report bases its estimates of oil security costs on two reports—Delucchi and Murphy (1996), and Lieby et al. (1997). But Delucchi and Murphy base their estimates on the assumption that all middle east oil consumption is ended, rather than on marginal reductions. And Leiby et al. state outright that oil security costs do not necessarily vary with marginal changes in imports. Thus, the research literature cited in the Report actually doesn't support the Report's assumption that the U.S. could achieve marginal reductions in oil security cost through marginal reductions in petroleum consumption.

Ironically, reducing petroleum demand is instead likely to increase the percentage of oil imports that come from the middle east. Middle eastern countries are generally the lowest-cost suppliers, so reductions in demand would push other suppliers out of the market, increasing the middle east's market share.

Improvements in oil security account for roughly 10 to 15 percent of the Report's estimated benefits from reducing petroleum dependence. Since these benefits would not actually materialize, they should be removed from the Report's benefits ledger.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Lynne Kiesling is director of economic policy at Reason Foundation and senior lecturer in economics at Northwestern University.

Resurrection of Ethanol Mandates

info@reason.org (Joel Schwartz) — Tue, 10 Jun 2003 00:00:00 EDT

Imagine the federal government forced you to spend $180 to buy an 8-track tape player. Sounds absurd. What could be more useless in the 21st Century than an obsolete Disco-era music machine? But what if our elected officials were a bit more subtle? What if they instead forced you to pay $180 more each year for gasoline that contains an antiquated additive you don't need, and that could actually worsen air quality? That is exactly what the energy bills moving through Congress propose to do.

The Clean Air Act requires that additives known as oxygenates, such as ethanol or MTBE, be added to gasoline sold in areas that have air pollution problems. Oxygenates were thought to reduce vehicle pollution when Congress enacted the requirement in 1990. MTBE, the current additive, is being phased out because it pollutes drinking water, leaving ethanol as the only alternative that satisfies the requirements. Since most ethanol is produced from corn grown in the Midwest, regional congressmen and their agribusiness constituents fervently support the oxygenate mandate, and were responsible for getting it into the Clean Air Act in the first place.

Lost in all these political machinations is the decisive scientific evidence that ethanol doesn't perform as advertised. Both the Environmental Protection Agency and the National Academy of Sciences have issued reports showing that adding ethanol to gasoline will at best have no effect on air quality and could even make it worse. Studies show ethanol could even increase emissions of nitrogen oxides and volatile organic compounds, which are major ingredients of smog.

What's more, adding ethanol costs about five cents extra per gallon and will reduce fuel economy by about 3 percent, for an effective cost increase of 10 cents per gallon. For the average family of four this will amount to about $180 per year - say goodbye to a nice chunk of your tax cut. And if ethanol demand outstrips supply, as many energy analysts predict, motorists could suffer much bigger price increases, as much as 50 cents a gallon according to some estimates.

Despite the scientific case against the oxygenate mandate, House and Senate energy bills include provisions to replace MTBE with ethanol.

Perhaps Midwestern farmers and their powerful congressmen are too important to cross. But without a compelling policy goal, this is no longer a fight between saving money and saving the environment. Instead, the oxygenate mandate now boils down to this: agriculture interests want to make money, and they've gotten the federal government to force the rest of us to fork over cash for a product we don't need.

While oxygenates provide no environmental benefits, there are many positive ways to improve the environment that don't create unnecessary burdens for consumers. A growing number of states have experimented with innovative clean air programs that offer compliance assistance to small businesses and incentives to larger industrial facilities to achieve environmental gains beyond the minimum levels required by law. More and more states are rejecting cookie-cutter approaches and implementing their own more flexible and more carefully tailored environmental strategies.

If President Bush and members of Congress are genuinely concerned about improving air quality, they should continue to require states to meet the goals of the Clean Air Act, but give them the freedom to find the most effective ways of getting there.

President Bush has said that his administration "will ask not only what is legal, but also what is right - not just what the lawyers allow, but what the public deserves." Apparently, he thinks the public deserves to be forced to buy products they don't need for the benefit of powerful business interests. Since the President hasn't been able to stand up to the ethanol coalition and do what is right, hopefully the courts can.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

State of the Air Report

info@reason.org (Joel Schwartz) info@reason.org (Steven Hayward) — Tue, 01 Apr 2003 14:49:00 EST

On May 1, the American Lung Association (ALA) will release its annual "State of the Air" report on air pollution levels in American cities. Like previous "State of the Air" reports, the news is alarming. The ALA claims "nearly half of the US population" lives in areas with dangerous levels of air pollution. Metropolitan areas from New York to San Diego are given letter grades of "F" for air quality.

Before taking this year's ALA report at face value, reporters should ask the ALA report's authors a few questions to clarify the report's biases.

1. Is air quality in California, and the U.S. as a whole, better or worse than it was 10 years ago? Five years ago?

Discussion: Air pollution has been declining for decades. While southern California's air pollution remains the highest in the nation, southern California has made more progress than any other region. Figure 1 displays the improving trend in exceedences of the 1-hour ozone standard. National compliance with the 1-hour ozone standard went from about 50% in the early 1980s to 87% today.

About 40% of U.S. monitoring locations still exceed EPA's stringent new 8-hour ozone standard, but 8-hour ozone levels have been dropping as well. Virtually the entire nation (>99%) now meets all federal health standards for carbon monoxide, nitrogen oxides, and sulfur dioxide. More than 96% of the nation complies with PM10 standards (particulate matter under 10 micrometers in diameter), and the compliance rate is about 70% for EPA's stringent new annual PM2.5 standard. PM2.5 declined 33% between 1980 and 2000, with the most polluted areas once again achieving the greatest reductions (see Figure 2 for PM trends).

These declining trends will continue in the coming decade (see discussion of question 4 below).

2. Is every single person in each city or county with an "F" grade exposed to dangerous levels of air pollution?

[If the ALA spokesperson says "Yes" to this question, it will mean they do not know what they are talking about and reporters can stop taking notes. See discussion below.]

Follow up question: For each county, "State of the Air" lists the number of days per year exceeding the 8-hour ozone standard. How many individual monitoring locations in a given county exceeded the ozone standard that many times per year? [The correct answer is zero for almost all counties with more than one ozone monitoring site (see Figure 6 below).]

Discussion: ALA "State of the Air" reports give an entire county an "F" grade if only a single air quality monitor within a county exceeds the EPA's strict new 8-hour ozone benchmark more than 3 times per year. But in most metro areas only a few monitors ever register an exceedence. In some metro areas, only a tiny percentage of the population lives in proximity to air quality monitors that exceed the EPA standard.

For example, ALA gave San Diego an "F" for air quality, claiming that San Diego experienced 16 exceedences per year of the EPA ozone standard. In fact, only a single rural location, Alpine, exceeded the 8-hour ozone standard more than 2 times per year (see Figure 3). 99.7% of people in San Diego County breathe air that meets both the EPA 8-hour and 1-hour ozone standards. ALA greatly exaggerated ozone levels in other metro areas as well (see figures 4, 5, and 6).

This one of the ways in which ALA was able to claim half of all Americans live in areas with unhealthy levels of ozone—they simply included tens of millions of people who actually breathe clean air.

The point: One might argue that talking about the number of days smog is elevated somewhere in a region is not misleading and paints a fair picture of the nature of the regional pollution problem. But the health effects of smog depend on how often a given person is exposed. Since no one is exposed to smog anywhere near as often as the ALA claims, the public is being encouraged to vastly overestimate its risk from air pollution.

3. Does ALA believe that air that exceeds EPA's 8-hour ozone standard poses a major health risk?

Discussion: The EPA's new, stricter 8-hour ozone standard is was selected to offer protection to those people who are considered "most sensitive" to pollution, chiefly the elderly and people with respiratory ailments. Most Americans do not face significant risk from current levels of ozone. For example, the EPA projects that going from nationwide attainment of the 1-hour ozone standard to attainment of the 8-hour standard would reduce emergency room visits for asthma by 0.6 percent, even though the 8-hour standard is significantly more stringent. Comparison of air pollution levels in California counties shows that there is little relationship between air pollution levels and asthma prevalence (see Figure 7), while a recent study of California's Central Valley, funded by the California Air Resources Board, found that emergency room visits and hospitalizations for respiratory disease were lower on days with higher ozone. While no one believes ozone protects against respiratory harm, the effects of ozone at current levels are small enough that epidemiologists have difficulty detecting any change in health outcomes with changes in air pollution levels. Nevertheless, ALA claims 40% of Americans are "at risk" when air pollution exceeds the 8-hour ozone benchmark on just a few days per year.

4. Does the American Lung Association believe that, notwithstanding the decline in air pollution in the U.S. and California, air pollution is going to get worse in the future?

Discussion: ALA claims in the "State of the Air" that "the improvement in ozone levels seen in 1999-2001 is likely due to favorable weather conditions rather than significant new measures to reduce pollution," and "much air pollution cleanup has been stalled during the past five years, because the U.S. Environmental Protection Agency has failed to take steps to enforce more the more protective ozone standard adopted in 1997." (p. 3, col. 1).

In fact, the downward trend in pollution levels has been ongoing and will continue. On-road pollution measurements show emissions from gasoline vehicles are dropping by about 10 percent per year, as the fleet turns over to more recent models that start out and stay much cleaner than vehicles built years ago. Diesel truck emissions are also declining, albeit about half as fast. Although motorists are driving more miles each year and population growth means more motorists on the roads, these increases in driving are tiny compared to the large declines in vehicle emission rates and will do little to slow progress on auto pollution (see Figure 8).

Emissions from industrial sources will also continue to drop. Starting in 2004, EPA regulations require a 60 percent reduction in summertime NOx emissions from coal-fired power plants and industrial boilers—the major industrial sources of ozone-forming pollution, and a 20 percent reduction in PM-forming SO2 from power plants between now and 2010. These reductions are in addition to substantial declines in industrial NOx and SO2 emissions during the last 30 years.

Summary

Clearly "State of the Air" is designed to generate alarming headlines—and aid fundraising for the American Lung Association—rather than provide the media and the public with accurate information on air pollution. Last August Andrew Goldstein of Time magazine wrote: "Fuzzy math and scare tactics might help green groups raise money, but when they, abetted by an environmentally friendly media, overplay their hand, it invites scathing critiques. . ." (From "Too Green for Their Own Good?" Time magazine, August 26, 2002.)

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Steven F. Hayward is senior fellow in environmental studies at the Pacific Research Institute, and a resident scholar at the American Enterprise Institute.

Clearing the Air in California

adrian.moore@reason.org (Adrian Moore) info@reason.org (Joel Schwartz) — Sat, 01 Mar 2003 00:00:00 EST

California has made tremendous progress on air pollution during the last few decades, but still faces two major air quality challenges. Parts of the San Joaquin Valley and South Coast exceed federal standards for ozone and particulate matter by a large margin. Both areas are in danger of missing federal deadlines for meeting air pollution standards.

California can meet these challenges. Unfortunately, California lawmakers and regulators have often pursued unneces-sarily expensive and even counterproductive policies, while failing to exploit cost-effective pollution reduction opportunities. This brieﬁng paper summarizes the air pollution situation in the San Joaquin Valley (SJV) and South Coast (SC), recommends policies for achieving cleaner air more quickly and more cheaply than current policies, and assesses the political viability of the recommended approaches.

Why the Centers for Disease Control Hates the Suburbs

info@reason.org (Joel Schwartz) — Tue, 30 Jul 2002 00:00:00 EDT

HealthFactsandFears.com

Forget anthrax and terrorism. Public health experts have uncovered a more pernicious threat to Americans' health and safety — the suburbs. According to researchers at the Centers for Disease Control and university public health departments, developers are forcing tens of millions of unwitting Americans into dangerous suburban developments that isolate us from our neighbors, stress us out, make us fat, kill pedestrians, and fill our air with auto-generated smog.

Having declared "sprawl" a public health problem, CDC and other public health experts now want a say in how Americans live, work, and travel. Regardless of whether it's a good idea for public health advocates to have that kind of power, one would at least expect them to provide accurate information about the health implications of how we live. But surprisingly, our nation's health experts have the facts wrong on virtually every claim they make about suburban living and health.

CDC researchers fired the first salvo in the public health community's anti-suburb initiative with "Creating a Healthy Environment: The Impact of the Built Environment on Public Health." The report, paid for by Sprawl Watch, a slow-growth advocacy group, and prepared by Dr. Richard Jackson and Chris Kochtitsky of CDC, claims that suburbs force us to be sedentary, make us fat, and reduce our overall health. However, despite obesity increasing in American society, CDC's own data and other studies show suburbanites are healthier and more active than city dwellers — even after accounting for suburbanites' greater wealth and other demographic advantages.

For example, an official CDC report, "Health, United States, 2001," ironically found that suburban women are the group least likely to be obese. Furthermore, a recent study in the American Journal of Public Health concluded that city-dwellers face a greater mortality risk compared to people living in suburbs or rural areas, even after controlling for demographic differences such as age, race, sex, education, income, and marital status.[1] The same study also found that suburbanites are the most physically active group.

The Sprawl Watch report also claims suburbs make walking more dangerous. But according to the National Highway Traffic Safety Administration, the pedestrian injury rate from auto collisions dropped 50% for adults and 75% for children between 1975 and 2000, even as millions of people moved to those supposedly dangerous suburbs.

CDC's experts also err in claiming that suburbanization increases air pollution by forcing us to drive. If they'd checked actual air pollution data, they'd know that despite a 75% increase in driving between 1980 and 2000, ozone smog dropped an average of 21%, while airborne particulates declined 33%. Carbon monoxide declined 61%, all but eliminating health concerns for this pollutant.

On-road pollution measurements show that auto emissions are declining by about 10% per year, indicating that air pollution will continue to improve. Technological advances are solving auto pollution without the need to limit people's travel choices.

And rather than being forced, people drive because the automobile can't be beat for convenience and flexibility. Americans use public transit for only about 1% of all travel, and transit's share of travel has been declining for decades, even in densely populated cities with extensive public transit.

After bungling the diagnosis, the public health community has moved into even shakier territory by prescribing dangerous medicine. During a recent CDC-sponsored online conference — "Urban Sprawl: What's Health Got to Do with It?" — Dr. Jackson, along with a panel of university public health professors, recommended so-called "smart growth" policy measures to mitigate the imagined harm caused by suburban development.[2]

Smart-growth doctrine includes a suite of policies intended to increase urban population densities, limit expansion of cities, limit or stop road building, and expand public transit. Portland, Oregon comes closest to implementing the smart-growth program and was avidly promoted by the panelists during the CDC sprawl conference.

Portland actually had the greatest decline in housing affordability between 1990 and 2000 of any metropolitan area in the country, while Portland's highway congestion has become the worst among regions its size. And despite building an extensive light-rail system beginning in 1986, transit's market share for work-commute trips in Portland dropped almost 20 percent between 1980 and 2000.[3] This doesn't sound like a prescription for greater health and happiness.

Most Americans intuitively realize something the experts apparently don't: In our search for the good life, we must all make tradeoffs among a range of values and desires — a larger home and yard, safer neighborhoods, proximity to friends and family, commute time to work, better schools, leisure time, and more. We weigh these options based on our individual tastes and financial means. And for most of us, the outcome of this balancing act includes a preference for a single-family home and travel by car. Given suburbanites' greater health, they seem to know more than the experts about what's in their best interests.

When thinking about why suburbs are so common, public health officials have mixed up cause and effect. People don't live in suburbs because of greedy developers or careless planners. Developers build suburbs because people demand them.

In a dynamic and competitive housing market, developers have a tremendous incentive to find out what combination of amenities will most appeal to homebuyers. If people were clamoring to live in high-rise apartments or condos, developers would build them. Like their customers, developers weigh their options and put together the best package they can, given what they believe their potential customers most value and would be willing to pay.

It's easy to understand why the public health community is so mixed up. They've put knee-jerk anti-suburb ideology ahead of rigorous health research. If health experts really want to improve our lives, they must return to their core mission of protecting Americans from genuine health threats.

We'll always need dedicated health professionals' advice on how our choices might affect our health. But we also deserve a public health community that cares about us enough to respect our choices.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

[1] J. S. House et al, "Excess mortality among urban residents: how much, for whom, and why?" American Journal of Public Health, December 2000, pp. 1898-1904.

[2] CDC and the University of North Carolina School of Public Health, "Urban Sprawl: What's Health Got to Do with It?" — An archived video of the conference can be viewed on the Web here.

[3] The data for Portland, as well as a wealth of other data on transportation and land use, can be found at www.demographia.com.

Extended Producer Responsibility

info@reason.org (Joel Schwartz) info@reason.org (Dana Joel Gattuso) — Sat, 01 Jun 2002 00:00:00 EDT

Executive Summary

Environmental policymakers have increasingly turned their attention to the environmental impacts of products. One concept—extended producer responsibility (EPR)—has captured the hearts of policymakers globally. Variations on this concept have surfaced, but EPR policies generally impose a fee that is paid by manufacturers for targeted products, and establish specific "take-back" goals for each targeted material or product. EPR rests on the idea that if manufacturers pay for the post-consumer impacts of products, they will design them differently to reduce waste. But other opportunities to more fully include environmental values into product-design decisions exist, and their lack of realization should not be deemed “market failure,” but rather a natural consequence of the complexity of the design, production, and distribution of good and services, the physical impossibility of vigorously pursuing all values simultaneously, and the continual emergence of new values.

Most proponents of EPR assume that current product-design practices deter efficient resource use and don’t adequately mitigate environmental impacts. Yet product-design trends belie this assertion. Manufacturers are moving toward reduced material-use per unit of output, reduced energy use in making and delivering each product, and improved product performance—including environmental performance.

It is not clear that EPR programs accelerate or enhance this process for several reasons. First, the various goals of EPR programs are not necessarily compatible. For example, fees set to reflect recycling costs and thus encourage “design for recyclability” may discourage source reduction and use of lighter and more durable modern materials such as laminates, composites, and plastics. Second, there is no intrinsically right fee level for EPR programs. Packaging fees among European nations vary as much as 35-fold for identical products. Fee setting is generally a political, rather than a scientific or economic exercise. Resulting fees give manufacturers confusing and conflicting signals about which design goals to pursue. To date, EPR has been most frequently applied to packaging and electronics. There is no single model of EPR, so evaluating just a few experiences is at best only suggestive.

What does the record to date show? Germany’s celebrated take-back program for packaging has a mixed record, with high costs for performance achieved. Under its Green Dot EPR program, Germany exceeded its waste-recovery targets. But over same time period, with no EPR system in place, the U.S. experienced even greater reductions in total packaging used per unit of output. Canadian packaging manufacturers, who set a voluntary reduction target of 50 percent in packaging sent for disposal, achieved that goal four years ahead of schedule with no EPR and at lower costs than Germany. The Netherlands also had a voluntary approach to packaging reductions under which packaging consumption declined 6 to 15 percent per year initially, dropping to 1.5 percent in later years. Overall reductions in packaging materials were greater in the Netherlands than in Germany.

Effects of mandatory electronics take-back programs are either undocumented or ambiguous. If European Union (EU) EPR directives for electronics steer manufacturers away from plastics, EPR could reverse trends toward more lightweight materials use, increasing shipping costs and energy use. For some electronics products, EPR programs actually generate high costs with minimal or no gains in recycling or other environmental amenities.

Though mandated programs may generate costs with few environmental (or other product-value) gains, some voluntary programs are also emerging. These voluntary programs face several challenges that include: 1) finding mechanisms to attract customer participation; 2) establishing cost-effective collection and return networks for discarded products; 3) identifying markets and uses for returned products and materials; and 4) achieving cooperation where multiple firms are involved.

The performance of voluntary EPR programs depends on program design and the nature of the production and consumption marketplace within which the program operates. Voluntary take-back programs appear to have emerged when one or more of the following characteristics dominate: 1) a high risk of improper disposal and associated liabilities; 2) a high value associated with the discarded product; 3) relatively low-frequency, high-value transactions between a manufacturer and consumer; 4) relatively close or ongoing relationship between the customer and manufacturer; and/or 5) high-end products for which environmental goals may enhance customer loyalty.

The failure of voluntary EPR programs to emerge in some instances is not evidence of market failure. It is an indication that manufacturers anticipate more costs than benefits to their consumers from these programs, and that some barriers (for example, disadvantageous tax treatment for leased rather than purchased products) may inhibit introduction of take-back programs. If benefits from EPR in a particular situation appear likely to accrue, those potential benefits represent an entrepreneurial opportunity that will, over time, attract investment.

Industrial ecology—market-driven innovations to add economic value through investing in environmental improvements to products and manufacturing processes—offers a more comprehensive framework than EPR for achieving environmental benefits. It involves a systematic search by manufacturers for opportunities to reduce environmental impacts as a source for cutting costs or increasing customer benefits.

Four factors are driving the trend toward industrial ecology. First is consumers’ increasing concern for nature and environmental values. Second is the emergence of “smart” technologies that make possible new relationships between manufacturers and suppliers and between customers and consumers, and that heighten prospects for replacing production equipment with “knowledge equipment” (for example, use of tractormounted computers to allow for highly tailored and efficient fertilizer application). Third is increasing affluence, which is correlated worldwide with increased environmental investment. And fourth is production dynamics, in which companies, having tapped the “low-hanging fruit” of savings available from improving labor productivity and energy efficiency, are now looking for competitive advantage in smaller, dispersed opportunities such as pollution prevention and waste exchanges.

Industrial ecology transcends the common assumption that environmental investments undermine economic performance. But industrial ecology does not rest on the expectation that all waste reduction and pollution prevention will yield bottom-line benefits. Instead, industrial ecology is best understood as a discovery system—a way of organizing information and framing problems.

Mandated EPR programs override this discovery process, forcing creation of take-back schemes within a regulatory framework that prescribes institutional arrangements. Like earlier environmental regulations that prescribed technological responses, such mandates stifle innovative market processes, impose uniform procedures for diverse circumstances, and necessitate the acquisition and reporting of large amounts of implementation and compliance data without guaranteeing tangible environmental benefits.

Low-level Chemical Exposure Unlikely to Disrupt Endocrine System

info@reason.org (Joel Schwartz) — Mon, 01 Apr 2002 00:00:00 EST

Executive Summary

A. The Debate over Hormonally Active Chemicals

The endocrine system, a system of glands and the hormones they release, regulates the development of a fetus in the womb, sexual development and reproductive function, maturation of the brain and nervous system, and energy metabolism. Some researchers have postulated that a range of natural and synthetic chemicals in the environment could damage or disrupt human and animal endocrine systems at exposure levels much lower than what previous studies and regulatory agencies have determined to be dangerous or toxic. Proponents of this hypothesis have dubbed the implicated chemicals “endocrine disruptors.”

Many chemicals can exert toxic effects at high levels of exposure. Regulatory agencies set exposure limits for chemicals intended to protect even sensitive people from adverse effects due to chemical exposure, and few people are ever exposed to chemicals at levels above these safety limits. But proponents of additional regulatory safeguards believe that hormonally active chemicals could cause harm even at very low exposure levels. They observe that:

The endocrine system can be affected by very small amounts of certain foreign chemicals—much less than the levels tested in traditional laboratory animal toxicity studies;
There is evidence that some hormonally active chemicals can circumvent the normal defenses of developing organisms; and
The environmental persistence of some of these chemicals gives them more time to do damage.

Studies in the early 1990s raised concerns over whether synthetic chemicals were causing widespread harm through endocrine disruption. Researchers in Europe published a study reporting that average human sperm counts had declined by more than 40 percent between 1938 and 1990. Other researchers reported that male alligators in a pesticide-contaminated Florida lake had abnormally small penises and reduced fertility. A breast cancer study reported that a group of women with breast cancer had higher average levels of the insecticide DDT in their bodies than a group of otherwise similar women without breast cancer. More recently, researchers have reported that some chemicals can cause changes in the size and structure of reproductive organs in laboratory animals at doses well below regulatory safety limits and near the range of typical human exposures.

However, a number of other scientists are skeptical of the extent to which endocrine disruption plays a significant role in human and wildlife health. They agree that adverse endocrine effects have been demonstrated for several synthetic chemicals in laboratory settings, and are likely to have occurred in a number of human poisoning incidents and in wildlife habitats with high contamination levels. However, these researchers question the existence and importance of health effects from the relatively low exposures to chemicals typical of the everyday environment. They raise the following objections:

Inherent biases in human sperm count studies make them unsuitable for evaluating actual spermcount trends. Furthermore, long-term data from farm animals show no change in sperm counts over time;
Studies of the relationship between DDT and other organochlorine chemicals and breast cancer have been inconsistent, with most studies finding no effect;
Although some researchers have found endocrine effects in laboratory animals with very low doses of chemicals, other laboratories have not been able to duplicate these results; and,
Even if these low-dose effects exist, it’s not clear that they should be considered harmful, because the effects are subtle, and “natural” variations in diet, stress, and other factors can cause similar effects.

Typical chemical exposures in humans are generally hundreds to thousands of times lower than exposures considered worrisome based on traditional toxicity studies. The practical importance of endocrine disruption thus depends on whether very low exposures to commonly used chemicals can cause significant harm.

B. Identifying and Studying Hormonally Active Chemicals

Aside from the body’s own hormones, chemicals with hormonal activity fall into three broad classes: (1) synthetic chemicals used in industry, agriculture, and consumer products; (2) synthetic chemicals used as pharmaceutical drugs; and (3) natural chemicals found in many foods, particularly soy.

The U.S. Environmental Protection Agency (EPA) sets regulatory safety limits for synthetic chemicals that are at least 100 times less than the highest dose found to be without adverse health effects in laboratory animals. EPA uses these conservative safety limits due to the uncertainty in whether humans are more sensitive than laboratory animals to certain toxic effects, and because humans vary in their sensitivity to toxic effects. Human exposures are substantially lower than regulatory safety limits. The key question then for assessing the risk of endocrine disruption is whether chemicals could cause adverse health effects at exposures below regulatory safety limits, and within the range of typical human exposures.

Scientists have developed a number of tests, or “assays” for hormonal activity. For example, relativepotency assays determine the ability of a given foreign chemical to mimic one or more effects of a particular hormone. These tests show that while some pharmaceutical hormones are as potent as natural hormones, industrial and consumer-product chemicals are generally hundreds to thousands of times weaker than natural hormones.

C. Risks from Chemicals with Hormonal Activity

Scores of laboratory animal studies have confirmed that high doses of hormonally active environmental chemicals—that is, doses much greater than everyday environmental exposure levels—can cause a range of adverse effects. There is also limited evidence in humans of such effects due to chemical accidents and use of some pharmaceutical drugs. For example, diethylstilbestrol (DES), a synthetic estrogen roughly as potent as estradiol, was given to several million pregnant women between 1947 and 1971 in the mistaken belief that it reduced the risk of miscarriage. DES caused high rates of infertility in daughters and increased rates of undescended or abnormal testes in sons of DES-treated women.

Although these studies show hormonally active chemicals can harm a developing fetus, it is not clear if these results can be generalized to endocrine disruption by exposures to chemicals at the low levels found in the everyday environment. Both dose and potency determine toxicity, and the doses in these studies were far greater than exposures to chemicals at the low levels found in the everyday envrionment. Furthermore, DES is thousands of times more potent in its hormonal effects when compared to hormonally active environmental chemicals. The practical risk of endocrine disruption for human and wildlife health instead centers on the potential for adverse effects at doses well below regulatory safety limits, including exposures that could be encountered in everyday life.

Several researchers have studied low-dose effects of hormonally active chemicals, but with mixed results. For example, some researchers have found that the industrial chemical bisphenol A (BPA) increases mouse prostate gland weight at doses well below the lowest dose at which BPA had previously been found to have a physiological effect, and near the estimated “worst-case” human exposure level. However, other researchers were unable to duplicate these results. Similar discrepancies have occurred in laboratory animal tests of other chemicals.

Because of the controversy regarding low-dose effects, EPA and the National Institute of Environmental Health Sciences convened an independent expert panel to re-analyze data from 49 low-dose studies. The expert panel concluded that endocrine effects have been demonstrated for a number of chemicals at doses below their previously determined no-effect levels. Only BPA had any effects at doses near the range of human exposure. However, because the BPA effects could not be duplicated by some laboratories, the panel concluded that it is not clear whether the apparent low-dose effects of BPA represent a general property of the chemical. Because of the subtlety of the effects, the panel also concluded that it is not clear whether low-dose effects should be considered “adverse,” or merely biological changes that can’t be assigned a value label such as “bad” or “good.” For example, natural factors such as variation in diet, stress, and hormone levels during pregnancy appear to have as much influence on study results as low doses of the chemicals being tested.

Laboratory studies provide information on the types of chemical effects that are plausible at given dose levels. The next step is to go out into the world and see if there is evidence for actual endocrine disruption or other harmful chemical effects in humans or wildlife at typical chemical exposure levels. Epidemiological studies attempt to determine if particular health outcomes, such as cancer, endocrine disruption, or asthma, are associated with particular risk factors, such as diet, genetics, smoking, or exposure to environmental pollution. Although epidemiological studies are an important part of risk assessment, they are not as definitive as laboratory studies, because the subjects are not randomly assigned to “treatment” and “control” groups, introducing the potential for bias in study results.

Neurological Effects. Laboratory animal studies have found that exposure to a group of chemicals called polychlorinated biphenyls (PCBs) in the womb can cause later learning and behavioral disorders. Although the biochemical mechanisms for these effects are unknown, some researchers have suggested endocrine disruption, as well as alterations in neurotransmitters (the chemical signaling mechanism in the brain and nervous system) as possible factors.

Five studies have assessed whether humans are adversely affected by exposure to PCBs and a number of other persistent chemicals at the relatively low levels encountered in the everyday environment. Some of these studies have found that children who had higher PCB exposures in the womb performed more poorly on tests of intellectual and neurological development. Where effects were observed, children in the top 5 to 20 percent of PCB exposure generally performed up to several percent worse than less-exposed children on one or more neurological tests.

The results from these studies are inconsistent regarding the type and timing of observed health effects. For example, the Lake Michigan study found declines in test performance in school-age children while the North Carolina study did not, even though the PCB exposures were similar. Effects sometimes also appeared and then disappeared, or vice versa, among the same group of children assessed at different ages. Where effects were observed, they were relatively subtle—only a few percent in most cases. One of the studies also found that the association of higher PCB exposure with lower test performance disappeared for children who were breastfed. Thus the extent to which low-level PCB exposure has permanent negative effects on children’s development remains unclear, but appears at worst to be relatively small.

Another factor to consider in assessing current risk from PCBs is that the children in these studies were born roughly 8 to 20 years ago. PCB exposure, as well as exposure to other persistent chemicals in the environment, has declined substantially during the last 20 years, and continues to decrease. Thus, whatever the effects of these chemicals on children born in the past, current effects are now lower and will likely continue to decline.

Male Reproductive Health. In 1992, researchers in Denmark published an analysis concluding that human sperm counts had declined by more than 40 percent between 1938 and 1990. However, other researchers have argued that the samples of men who elect to donate semen are never representative of the general population, and that the degree of bias can vary in different directions at different times and in different places. For example, a study in Australia found that average sperm counts varied by more than a factor of two among five separate groups of sperm donors recruited by the same doctors, at the same hospital, using the same recruitment methods.

Farm animals provide a check on human sperm-count studies, both because humans and farm animals are likely exposed to most of the same chemicals present in the environment, and because studies in farm animals presumably avoid the potential for selection bias inherent in human studies with voluntary sperm donors. Researchers have found that sperm counts in farm animals have been constant during the last 70 years. Evidence for human sperm-count declines thus appears to be relatively weak.

Female Reproductive Health. Increased lifetime exposure to estrogen increases the risk of developing breast cancer. Because of the link between estrogen and breast cancer, some researchers have proposed that estrogenic chemicals in the environment might increase the risk of developing the disease. Although a few studies have found an association between exposure to persistent chemicals such as DDT and increased risk of breast cancer, most have not. Furthermore, the chemicals in question–DDT, dieldrin, and hexachlorobenzene–are exceedingly weak estrogens. As a result, a link between these chemicals and breast cancer appears to be biologically implausible. It thus appears that the potential for everyday exposures to estrogenic foreign chemicals to increase the risk of breast cancer has not been properly evaluated.

Wildlife Studies. There are a few cases in which wildlife health effects have been linked specifically to the mechanism of endocrine disruption due to environmental contamination. Examples include the following:

In a mollusk species called the dogwhelk, the marine fungicide tributyltin (TBT) can cause females to develop masculine characteristics, such as a penis, at exposure to concentrations as low as one-billionth of a gram of per liter (one part per trillion). Some European populations of dogwhelk began to recover after regulations reduced TBT use. Nevertheless, TBT concentrations are still high enough in some regions to endanger sensitive mollusk species.
A high rate of hermaphroditism has been found in some freshwater fish in England that live just downstream of some sewage treatment works (STW) wastewater discharges. In most cases, the causative agents appear to be natural estradiol excreted by women, and ethinyl estradiol, a synthetic estrogen in birth control pills, both of which are not completely removed by STWs. In a few other cases, estrogenic chemicals called alkylphenols, released from industrial plants, are responsible for the effects.
Many Great Lakes birds accumulated organochlorine chemicals in their bodies by eating contaminated fish in the 1960s and 1970s. These chemicals were likely the cause of high rates of eggshell thinning, deformities, and mortality in chicks. Although some Great Lakes bird species have made dramatic recoveries due to reductions in organochlorine chemicals during the last 20 years, other species continue to decline in the most contaminated locations.

D. Summary

Endocrine disruption has been unequivocally demonstrated in humans and animals at relatively high doses of chemicals—many times greater than typical human or animal exposures to environmental contaminants. Endocrine disruption has also been demonstrated in a few aquatic species due to low exposures to a few chemicals. However, the evidence for adverse hormonal effects from low-level chemical exposures in humans is much weaker. Subtle neurological effects may have occurred in some children due to PCB exposure in the womb, though the evidence is inconsistent. There does not appear to be credible evidence for hormonally active chemicals causing increases in breast cancer risk, or declines in sperm counts. Overall, the evidence suggests it is unlikely that adverse health effects due to endocrine disruption have occurred in humans from exposures to small amounts of foreign chemicals in the environment.

Air Pollution and Mortality

info@reason.org (Kenneth Green) info@reason.org (Joel Schwartz) — Tue, 12 Mar 2002 00:00:00 EST

Air pollution is a serious concern to many Americans. Historical evidence of lethally high air pollution concentrations, and oft-cited comparisons of modern air pollution exposures to cigarette smoking have put air pollution control high on most peoples� radar. That is perfectly sensible. Making the world a safer place for ourselves and our children is the highest human instinct.

But our instincts can also mislead us if we devote scarce public health resources toward risks that are small, of low probability, and costly to reduce, while other risks that are larger, of higher probability, and less expensive to reduce get short shrift. And we are particularly easy to mislead when news coverage treats new studies of risk superficially�devoid of context and devilish details.

On March 6, the Journal of the American Medical Association published one such study by C. Arden Pope and co-authors entitled, �Lung Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution.�[1] The Pope study contends that people living in areas with higher levels of fine, airborne particles are likely to die earlier than people living in areas with less fine-particle pollution. Specifically, the Pope study contends that living in an area with fine particulate levels 70 percent greater than average, results in a 6 percent increase in the risk of death over a 16-year period.

Although the authors claim to have demonstrated a substantial risk from air pollution, the analysis below will show they may have mistakenly attributed health risks to air pollution that are actually caused by other health-related factors omitted from their analysis. Furthermore, even taking the study�s results at face value, the study found a relatively small risk from particulates when compared with other risks people face, and America�s success in reducing air pollution means few areas now have particulate levels high enough to cause health damage.

Confounding Breeds Confusion

The Pope study is an �ecological study��that is, a study in which researchers observe people�s health, behaviors, and risk factors out in the real world, rather than in the tightly controlled conditions of the laboratory. Ecological studies are inherently limited because researchers cannot obtain detailed ongoing information about the relationships between people�s health and the potential causes of health risks. For example, the behavior of the subjects cannot be prescribed, and their diet, exercise and other health habits cannot be monitored on an ongoing basis. Pollution exposure can only be roughly estimated based on a few regional measurements, rather than actual individual exposure. Exposure is also uncertain because researchers don�t know how much time people spend outdoors, or whether they continue to live and work in the same place after their initial entry into the study.

As a result of these factors, it�s difficult to tell in an ecologic study whether observed health outcomes are the result of pollution exposure and not of other differences between people who live in high- and low-pollution areas. For example, if it turned out that people in high-pollution areas are more likely to drink or smoke, there�s a danger of inadvertently confusing an effect of alcohol consumption or smoking with an effect of pollution. This problem is known as confounding. Other confounders besides alcohol and smoking include diet, exercise frequency, income, marital status, �body-mass index� (BMI; a measure of obesity), and educational attainment.

The Pope study researchers accounted for most of these confounders in their analysis. But the factors were assessed only when people entered the study in 1982 and not afterward. If any of these factors changed after 1982, and if the changes were correlated with pollution levels, then the Pope study results would suffer from uncontrolled confounding. For example, if people in areas with higher pollution were also likely to get fatter between 1982 and 2000 when compared with people in lower-pollution areas, researchers could mistake an effect of body weight for an effect of air pollution.

According to the Centers for Disease Control, Americans indeed became much heavier, on average, during the last 20 years, and poorer people and minorities are at greater risk of obesity than whites and wealthier people.[2] If minorities and the poor are also more likely to live in areas with more particulate pollution, then it�s possible that increases in body weight or changes in some other health factor might actually be responsible for effects that the Pope study attributes to air pollution.

Similar concerns apply to other confounders, such as diet and smoking. For example, if the prevalence of smoking decreased more slowly in higher pollution areas during the last 20 years, then smoking might have actually been responsible for effects the Pope study attributes to air pollution.

Because the risks of smoking and obesity are so much larger than the risks the Pope study estimated for fine particulates, even a small difference in smoking and obesity trends between areas with differing pollution levels could swamp the claimed effect of differences in air pollution. For example, the Pope study found that a 70 percent increase in the concentration of fine, airborne particle levels increases risk of dying prematurely by 6 percent. But for a six foot, 200-pound, non-smoking man, gaining just 15 pounds increases the risk of an early death by 17 percent.[3]

Two other findings in the Pope study suggest that the authors� efforts to control for confounding were incomplete. First, the study found that particulate exposure increases the risk of lung cancer for men, but not for women. Second, the association of air pollution and either cancer or cardiopulmonary mortality held only for people with a high school education or less.

There are also other potentially confounding factors that the Pope study did not assess at all, including income and wealth, and physical activity levels. These factors also have a strong relationship to health and could have changed over time in ways that could cause misattribution of health effects to air pollution when they were actually due to other factors.

Assumptions Aren�t Always Accurate

While it is very important to determine whether low-level exposure to airborne particles poses a risk to human health, such research must be based on sound assumptions in order to provide valid information about health risks. Nevertheless, the Pope study authors made a number of questionable assumptions that should have steered them away from claiming to have generated the �strongest evidence to date� regarding the relationship between airborne particles and human health.

Regarding exposure, the study�s authors assumed that everyone within a zip code was exposed to the same level of particulate pollution, though evidence shows such exposure can vary widely. Not only does exposure vary from place to place in concentration, in the chemical composition of the particles.

The authors also assumed people told the truth on the initial questionnaires regarding how much they smoked and drank. But survey researchers have observed that people tend to under-report these behaviors. Thus, if the authors used survey responses to account for smoking and drinking, they could be underestimating that risk in their study population.

The authors also assumed that health-related behaviors did not change after the entrance survey in 1982. For example, this means the authors assumed that if one did not smoke on the entrance survey, one would not take it up, and that people who filled out surveys in 1982, and later died in the same area where they originally lived, had stayed there throughout. As noted in the previous section, this problem also applies to other health-related factors such as change in weight and diet after entering the study.

Context Offers Clarity

The Pope study authors contend that the study provides �the strongest evidence to date that long-term exposure to fine-particulate air pollution common to many metropolitan areas is an important risk factor for cardiopulmonary mortality.� Media reports on the study were also uncritical in repeating the study�s findings, while giving short shrift to its many limitations.[4] But even if we take the Pope study�s results at face value, the study greatly exaggerates actual risks, and does a poor job of placing the risk of particulate air pollution into the context of other risks people face.

The analysis in previous sections shows that the study�s authors may well have mistakenly attributed health risks to air pollution that are actually caused by other factors. But even ignoring this concern, the study found a relatively small risk from particulates. For example, the study found that reducing particulate levels by 60 percent would reduce risk of dying during a 16-year period by about 6 percent. But, a six foot, 215 pound, non-smoking man can achieve the same risk reduction by losing about five pounds, and three times the risk reduction by losing about 20 pounds.[5]

The Pope study also found that most of the health benefits from reducing airborne particulate levels accrue from reducing particulates down to a concentration in air of about 18 micrograms per cubic meter (mcg/m³). Reductions below this level provided little or no additional health benefit. But according to the Pope study�s pollution measures, all but 2 of 51 metropolitan areas were already below 18 mcg/m³ as of 1999-2000. National fine-particulate monitoring data also show that few areas of the country now have particulate levels above 18 mcg/m³.[6] Thus, even if the small additional health risk reported by the Pope study is real, few people are exposed to it.

Ongoing reductions in particulate levels also mean that future particulate levels will be even lower, further reducing risk. For example, total particulate emissions dropped 75 percent between 1940 and 1997, while per-capita emissions dropped more than 85 percent.[7] Total particulate levels in air declined about 50 percent between 1960 and 1990, while coarse plus fine particulates declined 19 percent between 1991 and 2000.[8] The health hazards discussed in the Pope study occur only after many years of exposure to elevated particulate levels. Continuing declines in particulate pollution suggest that remaining risks will not persist for long enough to damage health in the future.

The Pope study also provides little context on the pitfalls of ecological studies and of epidemiologic studies in general. A number of authorities in the field of epidemiology have concluded that studies that find relatively small increases in risk associated with various health risk factors are often unreliable, due to the likelihood of undetected confounding or bias (see discussion of confounding above).[9]

Everyone deserves air that�s safe to breathe, and most Americans agree on the importance of improving air quality in places where air pollution is high enough to threaten health. But most Americans also want to know that public health resources are going where they�ll get the biggest bang for the buck�that is, toward larger, more certain risks, rather than toward small risks that might not even be real. Exaggerating the public�s risk from air pollution is no better than ignoring real air quality problems. If society misspends scarce resources based on inaccurate information, more people will suffer, not fewer.

Dr. Kenneth Green is senior fellow at Reason Foundation and Chief Scientist at Frasier Institute.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

[1] C. Arden Pope, et al., �Lung Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution, Journal of the American Medical Association, vol. 27, no. 9, March 6, 2002.

[2] National Center for Health Statistics, Health, United States, 1998, with Socioeconomic Status and Health Chartbook (Atlanta: Centers for Disease Control, 1999).

[3] E. E. Calle et al., �Body-Mass Index and Mortality in a Prospective Cohort of US Adults,� New England Journal of Medicine, vol. 341 (1999), pp. 1097-1105.

[4] G. Polakovic, �Research Links Air Pollution to Lung Cancer,� Los Angeles Times, March 6, 2002 (www.latimes.com/news/nationworld/nation/la-000016775mar06.story), and Andrew C. Revkin, �Soot Particles Strongly Tied to Lung Cancer, Study Finds,� New York Times, March 6, 2002 (www.nytimes.com/2002/03/06/health/06SOOT.html).

[5] Calle et al., �Body-Mass Index and Mortality in a Prospective Cohort of US Adults�

[6] U.S. Environmental Protection Agency, Initial Summary of Preliminary 1999 Fine Particulate Matter (PM2.5) Monitoring Data (Washington, D.C., 2000).

[7] I. Goklany, Clearing the Air: The Real Story of the War on Air Pollution (Washington, D.C.: Cato, 1999).

[8] Ibid.; U.S. EPA, Latest Findings on National Air Quality: 2000 Status and Trends (Washington, D.C., 2001). Methods for measuring particulates have changed over the years, as progressively smaller particles were found to be the main culprits for health effects. �Total particulates� includes all particles suspended in air, regardless of size; �coarse particulates� includes all particles between 2.5 and 10 micrometers (0.0025 to 0.01 millimeters) in diameter, while �fine particulates� includes all particles up to 2.5 micrometers in diameter.

[9] G. Taubes, �Epidemiology Faces its Limits,� Science, vol. 269, September 8, 1995, pp. 164-169.

Does Pollution Cause Ashtma?

info@reason.org (Joel Schwartz) — Wed, 20 Feb 2002 00:00:00 EST

While previous studies showed that air pollution can aggravate pre-existing lung ailments, a new study of children in southern California reports that frequent, strenuous, outdoor exercise, combined with high levels of ozone air pollution, can more than triple children's risk of developing asthma. This study, published in the Lancet, a prestigious British medical journal, is the first study to find that air pollution might actually cause asthma, not just aggravate it. Officials of the California Air Resources Board, which paid for the study, were quick to claim that its results applied not only to the six southern California communities where it was performed, but also to many cities across the country. ARB officials also maintained that the study justifies additional air pollution regulations in order to protect children's health. State and local public health officials and advocates echoed these sentiments in the many newspapers that carried the story.

But pollution-control advocates who invoke this study to justify ever more intrusive air pollution regulations are playing fast and loose with the numbers. Though high ozone levels of the past may have caused asthma in some parts of southern California, children exposed to current levels of air pollution are at virtually no additional risk of developing asthma.

In the Lancet asthma study, researchers followed two groups of children in southern California from 1993 to 1998. One group lived in six communities with low pollution levels; the other lived in six communities with high pollution levels. After accounting for factors besides pollution that could account for differences in asthma rates (such as income, ethnicity, parental smoking, etc.) the study found that:

Children in high-ozone communities who participated in three or more team sports (about 8 percent of all children in the study) were 3.3 times as likely to become asthmatic when compared with less-active children. Asthma was unrelated to sports participation in the low-ozone communities.
Children who spent the most time outdoors were 1.4 times more likely than other children to become asthmatic in the six high-ozone communities, but not in the low-ozone communities.
The study also measured other pollutants, such as airborne particulates and nitrogen dioxide, but found no relationship between these pollutants and asthma.
Despite the increased asthma rate found for very-active children in polluted areas, asthma rates did not differ overall between the high- and low-pollution areas.

The asthma study estimated children's ozone exposure using pollution measurements from 1994 to 1997. But southern California has made great progress on air pollution in the intervening years. The communities in the study went from an average of about 34 days per year exceeding the federal ozone health standard, down to an average of just 4 during the last two years a reduction of almost 90 percent. Even Crestline, California, which was not part of the study, but has the worst ozone in the nation, exceeded federal standards an average of 23 days per year for the last two years�about a third less often than the asthma study areas.

Ozone levels are far lower everywhere else. For example, a few other areas of California-San Bernardino, Riverside, Fresno, eastern Los Angeles County and Kern County-have about 5 to 15 high ozone days per year. Ozone across the Houston metro area exceeds the standard from one to 10 days per year. Beyond these regions, no other part of the country averages more than 4 high-ozone days per year, and most have one or none.

In other words, no American experiences ozone at levels similar to those of the asthma study, and more than 97 percent of Americans don't even experience one-tenth as many high ozone days. Clearly, regulators and public health advocates are wrong when they claim either that the asthma study has something to say about the risks of current air pollution levels, or that current regulations are not sufficient to reduce air pollution.

Proponents of the pollution-causes-asthma hypothesis also err in claiming that air pollution is partly to blame for rising asthma rates during the last 20 years. The Environmental Protection Agency reports ozone levels dropped an average of 24 percent between 1980 and 1999, and other pollutants also declined substantially. Areas with the most ozone pollution experienced the greatest improvement. And the asthma study itself also found no difference in overall asthma incidence when comparing high- and low-ozone communities.

Asthma is a serious disease and no one wants to take risks with their children's health. But for children to be at risk, they'd need to be frequently exposed to high ozone levels. Fortunately, they're not. Recent air quality improvements mean that no one in America is now exposed to high ozone as often as in the southern California study.

Asthma exacts a large health toll on our society, making it urgent that we learn what causes the disease and how to neutralize it. But regulators and activists do the public a disservice when they exaggerate health threats. Not only do they scare people for no good reason, they also divert attention and resources from real threats to people�s welfare.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Grading the Graders

info@reason.org (Joel Schwartz) — Thu, 06 Dec 2001 00:00:00 EST

Earlier this year, the American Lung Association handed out F grades for air quality to almost 60 percent of U.S. counties.[1] The Sierra Club recently followed suit, failing 70 percent of cities for their efforts to improve air quality with spending on public transit.[2] Based on these poor grades, advocacy groups are recommending billions of dollars in new regulatory costs and substantial new restrictions on Americans� freedom to choose where and how they live and travel. But what do these letter grades really mean in terms of peoples� actual health and welfare?

Simple grading systems are appealing because they boil down a wide range of complex information and analysis into a single letter that anyone can easily understand. Your county got an F for air quality? Then your air must be unsafe to breathe. Want to change those F�s to A�s? Prod your local officials into clamping down on automobiles and �suburban sprawl,� and building more public transit. That�s the idea anyway. Unfortunately, these grading systems turn out to have little to do with the actual environmental health and safety factors they purport to evaluate.

Sierra Club Mistaken On Link Between Transit and Air Quality

In its report �Clearing the Air with Transit Spending� the Sierra Club graded cities based on the fraction of transportation funding spent on public transit versus highways, and motor vehicle pollution per capita. Cities with greater transit funding and less per capita motor vehicle pollution received better grades.[3]

Though the Sierra Club claimed that cities with better grades are also doing a better job at reducing air pollution, it appears the report�s authors never checked to see if their grading system had any relation to actual air quality. It doesn�t. Figure 1 compares the Sierra Club�s grades for metro areas to actual pollution levels.[4] Note that cities that got the best grades from the Sierra Club have the worst air pollution�just the opposite of what one would expect if the grades tracked actual health risk.[5]

The Sierra Club recommends increasing transit funding, reducing road funding, and requiring higher density, transit-oriented development to fight sprawl, decrease driving and thereby reduce air pollution.[6] But as we�ve seen, the data show that there is no relationship between transit funding levels and air quality. That�s because in most American cities, more than 90 percent of people commute to work by car regardless of transit funding levels. Even in cities like Chicago and Washington, DC, which have extensive public transport, more than 80 percent of people commute by car. In the New York metro area, with by far the best public transit system in the country, two-thirds of commuters still drive to work.[7] There is also no correlation between trends in per-capita transit use and transit funding levels in American cities. Per-capita transit use declined in most metropolitan areas between 1990 and 1999, regardless of funding levels.[8]

Denser development also has little effect on the amount people drive. Using data from the National Personal Transportation Survey, researchers from the Georgia Institute of Technology found that nearly tripling metropolitan density decreases driving by only about seven percent.[9] People drive because the automobile can�t be beat for flexibility and convenience. Even in Europe, with its dense cities, extensive public transport, and $4 to $5 per gallon gasoline, automobile use has skyrocketed during the last few decades.[10] Europeans, like Americans, embraced the automobile when rising incomes put auto travel within reach of most households.

Number of high ozone days is average for all cities receiving given letter grade. Ozone data from EPA AIRData Web site, www.epa.gov/aqspubl1/annual_summary.html

American Lung Association Inflates Air Pollution Exposure

Just as with the Sierra Club, the American Lung Association�s (ALA) air quality grades also have little to do with actual air pollution levels in American cities. In �The State of the Air 2001,� ALA graded counties� air quality by tallying the number of days each year in which at least one monitoring location in a county registered an ozone level of at least 0.085 parts per million (ppm).[11] Unfortunately, this method vastly overestimates real air pollution exposure. For example, 99 percent of people in San Diego County live in areas that meet EPA�s ozone health standards (see Figure 2).[12] Nevertheless, ALA gave San Diego County as a whole an F grade for air quality, because one rural location (Alpine) with 0.3 percent of the county�s population has elevated ozone. ALA may thus have needlessly scared the 3 million residents of San Diego County into thinking their air is unsafe. ALA made the same error for dozens of other populous counties around the U.S., counting tens of millions of people as being exposed to high levels of air pollution, when in fact their air is clean.

Areas with fewer than four days per year exceeding 0.084 ppm ozone meet EPA�s 8-hour, 0.085 ppm ozone standard. See endnote 12 for explanation. San Diego County ozone data are from California Air Resources Board, �California Ambient Air Quality Data CD-ROM,� CD Number PTSD-00-014-CD, Planning and Technical Support Division, November 2000.

Overlooking a History of Progress

What is also lost in these simplistic letter grades is context. The Sierra Club and ALA discount America�s success in combating air pollution during the last 20 years. According to Environmental Protection Agency (EPA) monitoring data, average ozone levels in the U.S. dropped 24 percent between 1980 and 1999.[13] Areas with the worst air pollution have had the greatest success. For example, Los Angeles and Houston reduced high ozone days by 80 and 50 percent, respectively, between 1980 and 2000.[14] The nation achieved these reductions at the same time that driving increased by 75 percent.[15] Even as air quality continues to improve, ALA nevertheless claims that the number of people exposed to high air pollution levels is increasing.

The Sierra Club also errs in its claim that any air pollution improvements achieved so far are being �cancelled out,� because people are driving more, and more and more motorists are purchasing big Sport Utility Vehicles.[16] In reality, technological progress is winning the war on air pollution. On-road pollution measurements show that even with more SUVs on the road, the average new vehicle starts out cleaner and stays cleaner as it ages when compared with older models, and average emissions of the vehicle fleet are dropping several percent per year.[17] EPA predicts, based on regulations already on the books, that average motor vehicle per-mile emissions will drop by 85 percent during the next 20 years due to ongoing fleet turnover to cleaner vehicles. [18] This means that air pollution will continue to decline even with large increases in driving.[19]

Technological advances are bringing us cleaner air along with the single-family homes, automobile-based travel, and suburban lifestyles that most Americans desire. Unfortunately, the ALA and Sierra Club are only two among many advocacy groups using phony grading systems to foment public fear and increase support for unnecessary and undesirable restrictions on where and how we live and travel. In recent months, other groups have released equally misleading reports on the supposed dangers of suburban development for human health and welfare.[20] These reports, with their quantitative data analysis and university-style grades, have the patina of rigorous science, but none of the substance. Though �anti-sprawl� advocates earn failing grades in Science and Policy, by bombarding and bewildering the media and the public with specious analysis, they may just hoodwink their way into an A in Politics.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.

Endnotes

[1] American Lung Association, The State of the Air 2001 (Washington, DC, 2001)

[2] Sierra Club, Clearing the Air with Transit Spending (Washington, DC, 2001)

[3] Ibid.

[4] Air pollution data downloaded from the Environmental Protection Agency�s AIRData Web site, www.epa.gov/aqspubl1/annual_summary.html

[5] Number of high ozone days is the number of days in 2000 exceeding an ozone level of 0.084 parts per million, based on the most polluted location in each metropolitan area. The Sierra Club used �+� and �� grades, such as �B+� in its grading system. We�ve collapsed all grades into the letter grade alone for simplicity of presentation.

[6] Sierra Club, Clearing the Air with Transit Spending

[7] Data from Federal Highway Administration and 1990 Census, summarized in R. O'Toole, The Vanishing Automobile and Other Urban Myths (Bandon, Oregon: Thoreau Institute, 2001), p. 248-249.

[8] The Sierra Club report includes data by metropolitan area on both the number of dollars spent on public transit per $100 spent on roads, and per capita public transit spending. Combining these data with trends in per capita transit use between 1990 and 1999, we found a correlation coefficient of zero between both of the Sierra Club measures and trends in transit use. That is, cities with higher levels of transit funding experienced similar (downward) trends in transit use as cities with lower transit funding. Data on per capita transit use are from U.S. Department of Transportation, summarized in W. Cox, �Average Per Capita Public Transport Boardings Ranked by US Metropolitan Areas: 1999,� and W. Cox, �Annual Per Capita Boardings: 1980-1997 & Market Share,� both in Urban Transport Fact Book, on the Web at www.publicpurpose.com/ut-index.htm.

[9] C. L. Ross and A. E. Dunning, Land Use Transportation Interaction: An Examination of the 1995 NPTS Data (Atlanta, Georgia: Georgia Institute of Technology, 1997)

[10] Miles driven per capita increased by factors of 2 to 6 in major European cities between 1960 and 1990. See J. R. Kenworthy and F. B. Laube, An International Sourcebook of Automobile Dependence in Cities, 1960-1990 (Boulder, Colorado: University of Colorado, 1999), cited in R. O'Toole, The Vanishing Automobile and Other Urban Myths, p. 266.

[11] American Lung Association, The State of the Air 2001.

[12] EPA has two ozone health standards. To meet the current standard, no monitoring site in a region can exceed an ozone level of 0.124 ppm (averaged over a 1-hour period), more than 3 times in any consecutive three-year period. To meet the new standard, the average of the 4th highest ozone level (averaged over an 8-hour period) from each of the last three years must be less than 0.085 ppm. In practice, this means that, on average, no location can exceed 0.084 ppm ozone more than about four times per year and still comply with the standard. The new standard is not yet legally binding, but EPA hopes to implement it in the near future. All San Diego County locations except Alpine comply with both of the EPA ozone standards.

[13] Environmental Protection Agency, Air Quality Trends 1999 (Washington, DC, 2000).

[14] Based on ozone monitoring data from the California Air Resources Board and the Texas Natural Resource Conservation Commission.

[15] Vehicle use trends come from the U.S. Bureau of Transportation Statistics (www.bts.gov/btsprod/nts/ch1_web/1-29.htm) and the Federal Highway Administration (www.fhwa.dot.gov/ohim/hs99/tables/vm1.pdf).

[16] Sierra Club, Clearing the Air with Transit Spending.

[17] F. Gofa, et al., �Changes in on-Road Emissions and Emission Factor Model Predictions for the Van Nuys Tunnel: 1987 to 1995,� Submitted to Journal of the Air and Waste Management Association (2001).

[18] M. Beardsley, �MOBILE6: EPA's Highway Vehicle Emissions Model,� 11th On-Road Mobile Source Emissions Conference, San Diego, California (Coordinating Research Council, Atlanta, Georgia).

[19] For example, if per-mile motor vehicle emissions drop by 85 percent, and driving increases by 50 percent during the next 20 years, then total motor vehicle emissions would still drop by about 77 percent.

[20] See, for example, Surface Transportation Policy Project, Mean Streets 2000: Pedestrian Safety, Health, and Federal Transportation Spending (Washington, DC, 2000); R. J. Jackson and C. Kochtitzky, Creating a Healthy Environment: The Impact of the Built Environment on Public Health (Washington, DC: Sprawl Watch Clearinghouse, 2001).

Evaluating the American Lung Association's State of the Air Report

info@reason.org (Joel Schwartz) — Fri, 04 May 2001 00:00:00 EDT

According to "State of the Air," a report released on May 1 by the American Lung Association (ALA), "air pollution remains a major threat" to 141 million Americans, up seven percent from last year. If that were true, air pollution would be one of the most serious health challenges in the United States. However, the ALA report vastly overestimates Americans’ exposure to unhealthful air, and misleads the public into believing that air pollution is getting worse, when in fact it has been improving for more than 20 years. So, how did ALA get the numbers so wrong?

First, ALA incorrectly counted many clean-air locations as having unhealthful air. ALA cited a county as having a bad air day when at least one monitor somewhere in the county measured ozone at a level greater than or equal to 85 parts-per-billion (ppb) averaged over an eight-hour period. In fact, many counties with high ozone levels at some monitoring sites actually have other large areas with clean air. For example, in 1999 and 2000, one third of the monitored locations in southern California stayed below the level ALA defined as having an air quality violation. Roughly six or seven million people live in these clean-air locations, but were included by ALA in its tally of people exposed to polluted air. In a similar manner, ALA overestimated the extent of polluted air in other populous parts of the country, inaccurately adding millions of people in clean-air regions to its polluted-air tally.

Second, ALA overestimated the amount of time any given person is exposed to unhealthful air even in regions that exceeded the ozone standard. ALA calculated the number of bad air days for each county by counting the days in which any location in the entire county registered an ozone violation. But this number is much greater than the maximum number of bad air days at any single location, because ozone levels vary a great deal from place to place.

For example, Table 1 displays the number of ozone violation days during the three-year period from 1997 to 1999 at each monitoring location in Los Angeles County. As the table shows, Los Angeles County as a whole had 110 ozone violation days. However, no single location had more than 70 violations, and most had far fewer. Thus, even in the parts of the county that exceeded the ozone standard, ALA overestimated real exposure to polluted air by anywhere from a factor of 1.6 to a factor of 55, depending on the location. The same overestimation occurred in other parts of the country, including the Houston area, where the worst site exceeded the ozone standard on 45 percent fewer days than the county as a whole. ALA’s erroneous method of evaluation results in a substantial nationwide overestimation of people’s exposure to polluted air.

Table 1. Number of Ozone Violation Days for Los Angeles County as a Whole Compared with Individual Monitoring Locations

Ozone Monitoring Location in Los Angeles County	Three-Year Total of Ozone Violation Days, 1997-1999 (85 ppb, 8-hour ozone standard)
Anywhere in county	110
Santa Clarita	70
Glendora	68
Azusa	46
Pomona	38
Pasadena	33
Burbank	22
Pico Rivera	21
Downtown Los Angeles	14
Reseda	14
Hawthorne	2
Lynwood	0
North Long Beach	0
West Los Angeles	0
Source: California Air Resources Board

Third, ALA used a grading system that has little relationship to actual health risks from air pollution. ALA won’t give a county a clean bill of health, even if its air pollution levels satisfy the Environmental Protection Agency’s (EPA) stringent new ozone health standard. But EPA chose this standard specifically to protect those who are most sensitive to the effects of ozone. And even EPA’s Clean Air Science Advisory Committee, an independent panel of health scientists, concluded that even less stringent standards than the one EPA chose would be equally protective of public health. By using a standard even tougher than EPA’s, ALA was able to classify 30 million additional people as living in areas with poor air quality, even though air quality in those regions meets EPA’s stringent health standard.

Fourth, even though moderate ozone levels don’t harm most people, ALA included them in its figure for Americans exposed to unhealthful air. The EPA’s new ozone standard is set to protect the most sensitive groups—those with respiratory diseases, the elderly, and children with developing lungs. Roughly 90 percent of metropolitan areas that exceed the EPA standard never reach ozone levels that would harm the 60 percent of people that don’t fall into one of these sensitive groups. ALA’s tally thus includes tens of millions of people who wouldn’t be harmed even if ozone levels occasionally exceed the EPA’s new standard.

Fifth, ALA blurs the distinction between modest and severe air pollution problems. In the ALA grading system, counties with no pollution violations get a grade of A, and those that average 3.3 or more days per year above the ozone standard get a grade of F. This lumps Osceola, Florida, averaging 3.3 ozone violations per year, with Houston, which averages 61.5 violations per year. That’s a huge difference in real health risk between the two areas that’s not reflected in the ALA grades. ALA also makes the questionable claim that three or four days a year of ozone at levels slightly greater than an already stringent standard should be considered a "major threat" to public health.

Finally, ALA misleads the public about trends in air pollution levels. The fight against smog is a great success story in environmental protection. Southern California, the region with the worst air in the country, has reduced its number of bad air days by more than 75 percent between the late 1970s and the last few years. High ozone levels also occur over a much smaller region than in the past, exposing far fewer people. Likewise, Houston, the second most polluted area in the country, reduced ozone violations by about 55 percent over the same period. Most, though not all, metropolitan areas have seen similar improvements. Tough EPA pollution standards for new cars and trucks will ensure that air pollution levels continue to go down for the foreseeable future, as the national fleet turns over to new low-polluting vehicles.

Not only does the ALA report fail to show these ongoing reductions in air pollution, it doesn’t reflect current air quality particularly well either. For example, southern California’s ozone levels have been dropping rapidly for more than 10 years, with 1999 and 2000 the cleanest ever. ALA’s analysis masks these recent improvements.

ALA’s inaccurate and misleading report could cause tens of millions of people who breathe clean healthful air year-round to now incorrectly believe that their air is unsafe. Tens of millions more might believe that their air poses a major health threat, when in fact their real risk is minimal.

Ironically, ALA’s efforts could actually reduce Americans’ health and safety. The ALA report could cause the public to demand billions of dollars in expenditures to clean up air that is already clean. These wasted billions would harm people in two ways. First, in a world of limited resources, society can only address some of the many risks people face. Wasting money on phantom risks means that real risks go unmitigated. Second, health and safety improve over time as talented people progressively find cheaper and more effective ways of solving problems. But when people waste effort on fruitless endeavors, fewer real problems get the attention they deserve, reducing health and safety not only in the present, but in the long run as well.

Everyone deserves to breathe clean air, and nobody wants to see people suffering from pollution. A few areas of the country have serious air pollution problems that do threaten the health of people who live there. But exaggerating the public’s risk from air pollution is no better than ignoring real air quality problems. If society misspends scarce resources based on inaccurate information, more people will suffer, not fewer.

Joel Schwartz is an adjunct fellow at Reason Foundation and visiting scholar at American Enterprise Institute.