U.S. Environmental Protection Agency (EPA) Assistant Administrator Gina McCarthy announced Friday that they are proposing new air quality particulate standards to go into effect in December 2012. Though EPA is required to review air standards every five years under the Clean Air Act and had apparently already decided on reducing the particulate level, EPA wanted to delay the new standards until 2013. However, a suit filed by eleven states: New York, Connecticut, Delaware, Maryland, Massachusetts, New Mexico, Oregon, Rhode Island, Vermont, Washington and California and several environmental groups forced the EPA to act now. The court found that the EPA failed to adequately explain how the primary annual 2.5 micron particulate standard (PM 2.5) provided an adequate margin of safety for the most vulnerable-children, the infirm and the old.
A study of children in Southern California showed lung damage associated with long-term particulate exposure, and a multi-city study found decreased lung function in children associated with long term particulate exposure. These two studies appeared to warrant a more stringent annual particulate standard according to the court. The United States particulate levels are a small fraction of the levels in the worst areas of the world-Beijing, New Delhi, Santiago (Chile), Mexico City, Ulaanbaatar (Mongolia), Cairo (Egypt), Chongqing (China), Guangzhou (China), Hong Kong, and Kabul (Afghanistan).
Currently, under the Clean Air Act the US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard is 15 ug/m3 (an air quality index, AQI of 49). The 24-hr standard was last revised to a level of 35 ug/m3 (an AQI of 99). These standards were last reviewed in 2006, but no change was made at that time. It was reported that the EPA’s analysis found a lower standard for the annual exposure would have prevented almost 2,000 premature deaths each year. Combustion engines and coal burning power plants are key contributors to PM2.5 particles, and according to the US EPA and World Health Organization, the smaller, finer pollutant particles measured by PM2.5 are especially dangerous for human health. Studies have shown that there is an increased risk of asthma, lung cancer, cardiovascular problems, birth defects and premature death from particles smaller than 2.5 microns in diameter that lodge deep in the lungs.
According to the Lung Association, the two biggest air pollution threats in the United States are ozone and particle pollution. Other pollutants include carbon monoxide, lead, nitrogen dioxide, sulfur dioxide and a variety of toxic substances including mercury that appear in smaller quantities. The EPA, requires states to monitor air pollution to assess the healthfulness of air quality and ensure that they meet minimum air quality standards. The recently challenged, Cross-State Air Pollution Rule (CSAPR) was intended in part to prevent pollution from one state from moving into other states and preventing them from meeting their goals because several states have been unable to meet the current standard. PM2.5 particles can be either directly emitted or formed via atmospheric reactions. Primary particles are emitted from cars, trucks, and heavy equipment, as well as residential wood combustion, forest fires, and agricultural waste burning. The main components of secondary particulate matter are formed when pollutants like NOx and SO2 react in the atmosphere to form particles. However, studies have shown that air currents over the Pacific are carrying elevated particulate levels into California presumably from China.
According to American Lung Association State of the Air Report, Pittsburgh had the highest particle pollution in the nation on an annual basis. Seven cities averaged particulate levels higher than the 15 ug/m3 current standard allows: Bakersfield, CA; Hanford, CA; Los Angeles, CA; Visalia, CA; Fresno, CA; Pittsburgh, PA; and Phoenix, AZ. The American Lung Association in their latest report states that twenty cities actually have average year-round particle pollution below the current regulated level, but above the proposed EPA air quality standard of 12-13 ug/m3. The maximum 24 hour standard will remain unchanged at 35 ug/m3.