EPA Revises Air Quality Standards for Particles, 9-20-06
The U.S. Environmental Protection Agency (EPA) concluded a nine-year review of the National Ambient Air Quality Standards (NAAQS) for particulate matter (PM) on September 20, 2006 by ratifying the pre-existing annual average standard for fine particles and somewhat lowering the 24-hour average standard. Public health organizations and the Agency’s own science advisors were disappointed with the final ruling, which failed to follow their recommendations for health-protective standards.
The final rule:
- retained the annual average PM2.5 standard of 15 ug/m3;
- lowered the 24-hour average PM2.5 standard from 65 ug/m3 to 35 ug/m3;
- tightened the criteria under which “spatial averaging” would be allowable to demonstrate compliance with the annual average standard;
- recinded the annual average PM10 standard;
- reaffirmed the 24-hour PM10 standard of 150 ug/m3;
- established secondary standards to protect public welfare identical to the primary standards to protect public health;
A copy of the final rule, EPA fact sheets, and maps area available at:
