Category Archives: Particulate Matter

There’s No Doubt What EPA Staff Thinks Should Be the Result of EPA’s Reconsideration of the PM2.5 NAAQS

Late last week, EPA released an external review draft of the “Supplement to the 2019 Integrated Science Assessment for Particulate Matter.”  For those of you who don’t recall, the original Integrated Science Assessment was the report by EPA scientists that very clearly called for a decrease in the National Ambient Air Quality Standard for PM2.5.  It was criticized by the Chair of the Clean Air Act Science Advisory Committee and ignored by Administrator Wheeler,… More

Does Pollution Make You Dumber? (And Other Questions About Exposure to Particulate Matter.)

Most people other than Andrew Wheeler and the Trump Administration Clean Air Science Advisory Committee know that exposure even to low levels of PM2.5 causes increased morbidity and mortality.  And now comes evidence that exposure to PM2.5 may adversely impact cognitive capacity as well.  If the evidence is correct, then the externalities created by activities that release PM2.5 are likely much more significant than we had realized,… More

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

Who Gets To Decide What is a Major Source That Requires a Permit? That’s a Fine Question

The recent decision by the 8th Circuit that the Coyote Creek Mining Company did not require a major source permit under the Clean Air Act is both fascinating and important.  The question on the merits was whether CCMC had to include its fugitive emissions in determining its potential to emit.  Such emissions are normally excluded, but are included if they are part of a “coal processing plant.”

The Court concluded that the regulations are ambiguous and that EPA guidance did not resolve the issue. … More