EPA Proposes Clean Air Standards for PM2.5

In response to a court order, the U.S. Environmental Protection Agency (EPA) proposed updates on June 15 to its national air quality standards for harmful fine particle pollution, including soot (known as PM2.5). The agency says that 99% of U.S. counties are projected to meet proposed standards without any additional actions.

These microscopic particles can penetrate deep into the lungs and have been linked to a wide range of serious health effects, including premature death, heart attacks, and strokes, as well as acute bronchitis and aggravated asthma among children, the agency says. A federal court ruling required the EPA to update the standard based on best available science. The proposal, which meets that requirement, builds on steps already taken by the EPA to cut pollution in communities across the country, the agency’s press release says. Thanks to these steps, 99% of U.S. counties are projected to meet the proposed standard without any additional action.

The EPA’s proposal would strengthen the annual health standard for PM2.5 to a level within a range of 13 micrograms per cubic meter to 12 micrograms per cubic meter. The current annual standard is 15 micrograms per cubic meter. The proposed changes, which are consistent with the advice from the agency’s independent science advisors, are based on an extensive body of scientific evidence that includes thousands of studies, including many large studies that show negative health impacts at lower levels than previously understood. By proposing a range, the agency will collect input from the public as well as a number of stakeholders, including industry and public health groups, to help determine the most appropriate final standard to protect public health.

This proposal has zero effect on the existing daily standard for fine particles and the existing daily standard for coarse particles (PM10), both of which would remain unchanged.

Meanwhile, because reductions in fine particle pollution have direct health benefits—including decreased mortality rates, fewer incidents of heart attacks, strokes, and childhood asthma—these standards have major economic benefits with comparatively low costs, the EPA says: "Depending on the final level of the standard, estimated benefits will range from $88 million a year, with estimated costs of implementation as low as $2.9 million, to $5.9 billion in annual benefits with a cost of $69 million—a return ranging from $30 to $86 for every dollar invested in pollution control." Although the "EPA cannot consider costs in selecting a standard under the Clean Air Act, those costs are estimated as part of the careful analysis undertaken for all significant regulations, as required by Executive Order 13563 issued by President Obama in January 2011," the agency says.

The Clean Air Act requires the EPA to review its standards for particle pollution every five years to determine whether the standards should be revised. The law requires the agency to ensure the standards are "requisite to protect public health with an adequate margin of safety" and "requisite to protect the public welfare." A federal court ordered the EPA to sign the proposed particle pollution standards by June 14, 2012, because the agency did not meet its five-year legal deadline for reviewing the standards.

The EPA will accept public comment for 63 days after the proposed standards are published in the Federal Register. The agency will hold two public hearings: one in Sacramento, Calif., and one in Philadelphia, Pa. Details on the hearings will be announced shortly. The EPA will issue the final standards by December 14, 2012.

This map shows counties not expected to be in attainment in 2020.

—Edited by Dr. Gail Reitenbach, COAL POWER’s managing editor. This story first appeared in POWERnews.

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