Yesterday, EPA formalized its decision to leave the ozone 
NAAQS unchanged, at 70 ppb. I don’t think that this decision is in the same category of egregiousness as EPA’s recent decision not to reduce the PM2.5 NAAQS. After all, only one decision can be the single worst environmental policy of an entire administration.
I’m not that close to the science on the ozone NAAQS,… More
In April, I noted that researchers at the T.H. Chan Harvard School of Public Health had identified a relationship between PM-2.5 exposure and mortality from COVID-19. 
That study received some criticism, and it certainly did not move the Clean Air Science Advisory Committee to alter its recommendation to keep the PM2.5 NAAQS unchanged at 12 ug/m3.
Earlier this month, the same researchers updated the study,… More