The Environmental Protection Agency (EPA) has completed a long review, and reaffirmed the primary National Ambient Air Quality Standards (NAAQS) for particulate matter (PM), including those for PM-10 (particulates with an aerodynamic diameter less than or equal to 10 microns) and PM-2.5 (less than or equal to 2.5 microns; also call “fines”). On December 4, EPA announced it would retain the PM standards set in 2013, despite comments presenting recent scientific evidence – including evidence that higher pollution levels exacerbate harm from COVID-19 -- and seeking tighter standards.