EPA Limits for Particulate Matter Standards Draw Criticism (1)

The EPA proposed Friday to strengthen standards for fine particulate matter, announcing new levels that have left many environmental groups pushing for more change.

The proposal lowers primary levels of particulate matter, or PM 2.5, in the ambient air, which states must use as a baseline to stem their pollution under National Ambient Air Quality Standards. “Primary” levels under air quality rules are set based on what best protects public health, according to the Clean Air Act.

The new proposal will strengthen the 2012 standards from 12 micrograms per cubic meter to within the range of 9 to 10, Environmental ...