Category Archives: PM2.5

EPA Is Reconsidering the PM2.5 NAAQS. The Sooner, the Better.

EPA announced yesterday that it will “reconsider” the Trump EPA’s decision not to change the PM2.5 National Ambient Air Quality Standard.  I’ve blogged numerous times about the growing body of evidence that exposure to concentrations of PM2.5 below the current NAAQS causes significant additional mortality and morbidity.  The evidence is clear.

I certainly agree that climate change is an existential threat and that’s where our emphasis needs to be. … More

PM2.5 and Environmental Justice — and Electric Vehicles– and Tires

I’ve frequently discussed in recent years the mounting evidence for the need to lower the National Ambient Air Quality Standard for PM2.5.  There is also substantial evidence that PM exposure is an environmental justice issue.  In this context, electrification of our transportation system is seen as having a substantial co-benefit in the reduction of vehicle-related PM emissions, particularly in EJ communities. 

Two recent stories both confirmed the validity of these issues and made manifest the complexity of the problems we are trying to solve. … More

In Case You Were Wondering, EPA’s PM2.5 Decision Really Was Horrible

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

EPA Finalizes Decision to Retain the Existing PM2.5 NAAQS — Single Worst Environmental Decision of the Trump Administration?

Yesterday, EPA finalized its decision to retain the existing PM2.5 NAAQS of 12 ug/m3, rejecting substantial scientific evidence that PM2.5 causes significant harm at concentrations below 12 ug/m3.  In fact, as noted in one of my prior posts on this subject, an article in the New England Journal of Medicine estimated that exposure to PM2.5 at concentrations below 12 ug/m3 causes more than 10,000 deaths annually. … More