written by Ted Schetter, MD, MPH
Science Director for CHE and the Science and Environmental Health Network
This month the US Court of Appeals in Washington, DC, upheld EPA’s 2012 decision to tighten air quality standards for fine particulate air pollution (PM 2.5) by lowering the annual average limit from 15 to 12 microgm/m3. The EPA selected the new standard because it is slightly below the lowest long-term average concentration known to cause adverse health effects, including damage to the lungs and cardiovascular system and premature death in people with heart and lung disease. The National Association of Manufacturers, the US Chamber of Commerce, and other industry groups had challenged the scientific basis of this decision, also objecting to EPA’s plan to eliminate the use of spatial averaging in determining compliance and to require near-road monitoring in certain heavily populated urban areas. The court’s affirmation of each of EPA’s decisions was timely since each year the Asthma and Allergy Foundation of America declares May to be “National Asthma and Allergy Awareness Month.”
We have known for many years that particulate air pollution aggravates existing asthma, making symptoms more frequent and severe. Recent studies show that exposure to airborne fine particles can also make the disease more likely to develop in children who were previously asthma-free. The Southern California Children’s Health Study is a long-term investigation into the health effects of air pollution in children, some of whom live or go to school near major highways. This study finds that nearby traffic-related air pollution is more strongly related to asthma onset than regional measures of pollution that fail to recognize more localized spikes. As data have accumulated, the scientists now estimate that about 8% of cases of asthma in Los Angeles County are at least partially attributable to pollution associated with living within 75 meters of a major road. Rob McConnell, a professor of preventive medicine at USC and a principal investigator in this study, estimates that each case of asthma associated with living near a major road costs families about $4,000 a year in healthcare and other expenses.
According to the EPA, near-roadway monitoring in urban areas where more than one million people live and elimination of spatial averaging will more accurately assess the air that many people breathe in real-world conditions. The agency pointed out that the purpose of the Clean Air Act is to safeguard the quality of the ambient air, which is the “portion of the atmosphere, external to buildings, to which the general public has access”. That, the court said, obviously includes areas near roads.
Meanwhile, the Public Health Department of the County of Los Angeles and the California Air Resources Board had already issued recommendations regarding the citing of housing and schools near freeways, recognizing the need for a buffer zone to protect people from exposure to hazardous levels of traffic-related air pollution. Massachusetts includes the primary prevention of asthma in their state asthma management plan, and near-roadway air pollution is also getting increased attention there.
The fine-particulate court decision is one of several recent controversial cases addressing EPA actions. Last month the US Supreme Court ruled that the EPA did not overstep its authority under the Clean Air Act when it issued a regulation limiting power plant emissions that cross state lines. Also last month, the DC Court of Appeals upheld EPA restrictions on mercury emissions from coal-fired power plants. Now, as the agency takes on the even more difficult task of regulating greenhouse gas emissions from power plants we must do what we can to ensure that the best available science is used as the basis for decisions that will affect us all, including many future generations. Coal companies, utilities, the US Chamber of Commerce, and various state attorneys general are prepared to challenge EPA’s impending draft proposal to limit carbon emissions. The stakes are high.
1. View the ruling
2. see Health effects of particulate air pollution;
Particulate Matter (PM);
Outdoor air pollution, preterm birth, and low birth weight: analysis of the world health organization global survey on maternal and perinatal health