Particulate Air Pollution

Human Mortality, Pollution Sources, and the Case for Tougher Clean Air Standards

January 9, 1997

Particulate Air Pollution: Comments on EPA's Proposed Air Quality Standards (1996)


On November 27, 1996, the Environmental Protection Agency proposed new regulations for fine particulate matter (PM2.5) and ground-level ozone. We appreciate the opportunity to provide you with our comments on these proposals. While the majority of these comments focus on the standard for fine particulate matter, our comments on monitoring requirements address the ozone standards as well.

We believe that these proposals represent a critical step forward in protecting public health from air pollution. According to the Agency, the proposed particulate standards would avoid approximately 20,000 premature deaths, and dramatically reduce cases of asthma, bronchitis, and other respiratory problems. Our analysis confirms the Agency's contention that reductions in particulate matter will result in increased longevity; however, our estimates, like those of NRDC, suggest that a slightly stronger particulate standard would prevent a greater number of premature deaths, closer to the 70,000 that EPA originally suggested occur due to particulates.

The proposal noted that it was supported "by an overwhelming majority of independent scientists who reviewed the standard for EPA, based on 86 new health studies that indicate the need for a stronger standard." Our review of docket materials confirms that this is indeed the case.

Consistent with this overwhelming body of evidence, the Environmental Working Group fully supports the establishment of new, stricter standards for ozone and fine particulates. However, in order to fully protect public health consistent with the intent of the Clean Air Act, the science argues for even stronger standards for both particulates and ozone. Specifically, the Agency should make the following improvements to the proposal:

  • Abolish proposals for "spatial averaging" that will allow polluted areas to come into compliance by adding more monitors while doing nothing to clean the air.
  • Establish more stringent standards that provide greater public health benefits.
  • Ensure that there is no "backsliding" from current air quality conditions. Areas which currently have low PM 2.5 and ozone levels should be required to maintain those levels, and should not be allowed to "pollute up to the standard". And areas which are currently not in compliance should be brought into compliance simply because of changes in monitoring requirements.
  • Drop provisions that weaken current proposed standards by basing compliance with the annual standard on the 98th percentile. Instead, compliance should be based on a single exceedance.
  • Fulfill the public's right to know when their air does not meet basic safety standards.


We continue to support EPA's efforts to strengthen standards for ozone and particulate matter. These proposals respond to extraordinarily strong science showing that current standards are inadequate. However, we believe that our proposed changes would improve the regulations and improve your effort to more fully protect public health.