in the gross number of emitters.
"Between 1970 and 2020, the combined emissions of the six common pollutants (PM2. 5 and PM10, SO2, NOx, VOCs, CO and Pb) dropped by 78 percent."
https://www.epa.gov/clean-air-act-overview/progress-cleaning-air-and-improving-peoples-health#:~:text=Between%201970%20and%202020%2C%20the,the%20air%20that%20we%20breathe.
Clean AIR Act - 1970 - thanks Nixon
EPA - 1970 - thanks Nixon
Strengthening of the Clean Air Act 1990 - Thanks Bush 1
Edited by tigerinhogtown at 16:28:49 on 02/14/23