How toxic was my valley

Joel Schwartz’s latest, on EPA’s toxics report, in TCS Daily.

New York and California have the most toxic air in the nation, according to a new EPA report widely covered by the news media.[1] But having the most toxic air doesn’t tell us much. After all, no matter how clean the air is, somebody’s air has to be the worst in the country on any given measure. What we really need to know is how bad EPA claims the air is, and whether that claim is credible. Based on EPA’s own estimates, air pollution even in the “most toxic” areas of the country poses a miniscule cancer risk. More importantly, EPA’s cancer risk estimates are grossly inflated, because they depend on the false assumption that chemicals pose the same per-unit cancer risks at real-world trace exposures as they do at massive laboratory exposures.