In January of 2013, the U.S. Court of Appeals for the District of Columbia Circuit released a ruling requiring the U.S. Environmental Protection Agency to implement stronger requirements to clean up particulate matter, also known as “soot,“ one of the deadliest forms of air pollution.

Particle pollution does not just make people die a few days earlier than they might otherwise—these are deaths that would not have occurred if the air were cleaner.
(Chris Jordan-Bloch / Earthjustice)

Rejecting EPA’s adoption of a weaker approach, the Court ruled that the public health protections in the Clean Air Act require EPA to apply more stringent cleanup requirements in communities with unhealthful particulate matter levels.

Major sources of soot pollution include coal-fired power plants, factories, oil refineries, and diesel engines. The ruling means that more plants will be subject to more protective particulate matter limits in areas that violate health standards. It also will require limits not only on direct emissions of soot, but also on pollutants that transform into particulate matter in the air.

Under the ruling, the most stringent controls will apply to communities that fail to timely attain health standards (within four to six years). Among other things, these areas will have to implement the best available control measures (instead of just reasonably available measures) and achieve pollution cuts of at least five percent per year if they fail to meet standards on time.

The suit was brought by Earthjustice on behalf of American Lung Association, Natural Resources Defense Council, Sierra Club, and Medical Advocates for Healthy Air.