By Brett Rosenberg
October 9, 2006

In a controversial move, the Environmental Protection Agency September 21 officially strengthened regulations governing fine particulate pollution, known as soot. The new standards affect two categories of particle pollution: fine particles and inhalable coarse particles. Fine particles, referred to as PM 2.5, are 2.5 micrometers in diameter and smaller; inhalable coarse particles – PM 10 – have diameters between 2.5 and 10 micrometers. Exposure to particle pollution is linked to a variety of significant health problems ranging from aggravated asthma to premature death in people with heart and lung disease. Children, people with weak immune systems and the elderly are especially at risk to the adverse affects of soot pollution.

The agency strengthened the previous daily PM 2.5 by nearly 50 percent, from 65 micrograms per cubic meter to 35 micrograms per cubic meter; however, it retained the current PM 2.5 annual standard of 15 micrograms per cubic meter. The agency retained the existing daily PM 10 standard of 150 micrograms per cubic meter; and rescinded the annual PM 10 standard. Similarly, the EPA rescinded the PM 10-2.5 standard.

The Administrator’s decision is particularly controversial because for the first time in the agency’s 36-year history, it largely ignored the recommendations of its Clean Air Act Scientific Advisory Board. The board proposed tightening all of the soot standards, not just the daily PM 2.5, for which the advisory board recommended a 15 microgram per cubic meter standard – well beyond the standard the EPA chose. Citing major improvements in national air quality over the past few decades, as well as a suite of other recently enacted air regulations, EPA Administrator Stephen Johnson stated, “Regardless of the rhetoric, facts are facts – today EPA is delivering the most health protective national air standards in U.S. history to all 300-million Americans.” Johnson also pointed out projections that the new standards would save between $9 and $75 billion in health and environmental benefits when fully implemented in 2020.

The Federal Clean Air Act requires the EPA to review standards for what are known as criteria pollutants, which include particulate matter, every five years. Based on new scientific evidence and the advice of the Clean Air Act Scientific Advisory Committee, the EPA administrator can choose to adopt new standards, if new evidence warrants a change, or keep the status quo for a particular pollutant. In this instance, the advisory board and several EPA air quality experts recommended much stricter standards than those the EPA Administrator chose to implement.

Predictably, health environmental groups have weighed in on the decision, assailing the EPA for ignoring new studies showing the need for even more stringent soot regulations and further jeopardizing human heath and welfare. Industry groups have chimed in as well, voicing concerns that the new daily PM 2.5 standard is overly stringent and based on incomplete science.

The implementation schedule for the revised standards requires state recommendations for attainment and nonattainment designations by November 2007; EPA designations will be due by November 2009; designations take effect April 2010; State Implementation Plans will be due three years after designation (April 2013); and states need to attain the standards by April 2015, with a possible extension to 2020. Typically, cities work with metropolitan planning organizations, counties and state governments to implement policies to achieve air quality goals.