EPA Tightens Air Quality Limits for Particulate Matter Pollution

States will need to tighten up their compliance with soot limits under a new rule finalized by the EPA on Wednesday.

The Environmental Protection Agency decreased the amount of allowable particulate matter, or PM 2.5, permitted in the ambient air. Under the final rule, the EPA tightened the allowable threshold from 12 to 9 micrograms per cubic meter daily, the first change in the limits since 2012.

This “action is a critical step forward that will better protect workers, families and communities from the dangerous and costly impacts of fine particle pollution,” EPA administrator ...