Last month, I posted that EPA’s decision to retain the current PM2.5 NAAQS of 12 ug/m3 was the single worst decision by Trump’s EPA. Since then, I have not received any comments suggesting that my ranking was incorrect. In case anyone was still in doubt, Environmental Research recently released an on-line Pre-proof of A National Difference in Differences Analysis of the Effect of PM2.5 on Annual Death Rates. … More