The Environmental Protection Agency (EPA) on Dec. 7 announced its final decision to retain the existing National Ambient Air Quality Standards (NAAQS) for particulate matter without changes.
Particulate matter includes fine particles, which are 2.5 micrometers in diameter and smaller. They can be emitted directly from a variety of sources, including vehicles, smokestacks, and fires. They also form when gases emitted by power plants, industrial processes, and gasoline and diesel engines react in the atmosphere.
Coarse particles, which have diameters between 2.5 and 10 micrometers, include road dust that is kicked up by traffic, some agricultural operations, construction and demolition operations, industrial processes, and biomass burning.
EPA has regulated particle pollution since 1971 and has revised the standards four times -- in 1987, 1997, 2006 and 2012.
The Clean Air Act requires EPA to set two types of NAAQS for particle pollution: primary standards, to protect public health, and secondary standards, to protect public welfare.
The law requires EPA to review national air quality standards every five years to determine whether they should be retained or revised.
APPA submitted comments in support of EPA’s proposed action and believes that the record provided substantial justification for retaining the existing PM standards.
Click here for a copy of the pre-publication final rule and fact sheet, which provides details on the standards being retained by EPA.