Particulate Matter Air Pollution Tests

Comments of the <%$alawtitle%> on the proposed revisions to the ozone and particulate matter air quality standards (Docket #A-95-58 and Docket #A-95-54)
January 15, 1997

The new National Ambient Air Quality Standards (NAAQS) for ozone and particulate matter should be set at tighter levels than those proposed by the Environmental Protection Agency (EPA) to protect the health of Washington citizens. The Clean Air Act mandates that the NAAQS be set at a level to protect public health with a "margin of safety." Stricter standards than those proposed by the EPA are needed to provide this "margin of safety," and ensure that the health of sensitive individuals, such as people with asthma or emphysema, children, and the elderly is protected. According to the Clean Air Act the EPA must base the new standards on health and environmental effects, and other issues such as timing and cost should only be addressed during implementation.

In Washington state the main sources of particulate matter are motor vehicles, wood stoves, open burning, and industrial emissions. The health effects from these combustion sources are primarily from fine particles (PM_2.5) which are currently not federally regulated. These particles are hazardous because they are small enough to be inhaled deeply in human lungs. More than 50 epidemiological studies have been performed in different parts of the world, in different kinds of climatic conditions, and from different particulate sources, and the majority of the studies have found adverse health effects from particulate matter at levels lower than the current federal standard. Particulate air pollution has been associated with increased respiratory illness or chronic respiratory symptoms, asthma aggravation, increased hospital admissions, and premature death in many U.S. cities.

Scientific studies performed in Washington state have indicated that citizens are at risk for adverse health effects from particulate matter. A University of Washington study found that roughly one in eight emergency room visits for asthma in Seattle was linked to particulate air pollution. A study published in January 1996 by Joel Schwartz, Associate Professor at Harvard School of Public Health, found an association between particulate matter less than 10 microns in diameter (PM₁₀) and respiratory hospital admissions in Spokane. The Natural Resources Defense Council estimated that in the Washington state metropolitan area 1,400 people die prematurely each year from exposure to particulate matter, while a <%$alatitle%> report, Dollars and Cents, estimated that over $340 million in medical costs could be prevented each year in Washington state if the federal government adopted California's stricter PM₁₀ Standard (50 µg/m³, 24-h daily average, 30 µg/m³ annual average).

In July 1996 ozone reached unhealthy levels in Washington state, levels that nearly exceeded the federal standard. Ozone air pollution contributes to lung disease and has been linked to increased hospital admissions and emergency room visits for asthma. Ozone exposure may lead to shortness of breath, chest pain on deep inspiration, and wheezing and coughing. Those most at risk to ozone pollution are the elderly, children, asthmatics, people with chronic respiratory diseases, and individuals who exercise outdoors. Children are especially at risk because they spend more time outdoors than adults and their airways are smaller and more susceptible to air pollutants. A recent study by the American Lung Association and the Harvard School of Public Health found cardio-pulmonary emergency room visits and hospitalizations doubled on days with high ozone levels in some areas of the United States. Another study published in October 1996 found that healthy outdoor workers experienced a decline in their lung function after being exposed to ozone concentrations below 0.085 ppm. This decline in lung function from ozone persisted to at least the following day. The EPA should adopt a 0.07 ppm, eight hour standard for ozone, which should be rounded down, and would thus provide the greatest protection.

The EPA should adopt a new standard for PM_2.5, no higher than 18 µg/m³ (24 hour average) and 10 µg/m³ (annual average), and set tighter standards for PM₁₀. The EPA should select the monitor in a given area with the highest annual average as the basis for determining attainment with the annual standard, instead of using spatial averaging as currently proposed. This approach would ensure that people living in areas with the highest levels ("hot spots") are adequately protected from PM_2.5. This is extremely important in Washington state where we have "hot spots," and do not sustain high levels of particulate pollution over long periods of time, as often occurs in the Eastern United States. Furthermore, the EPA should retain the current one-exceedance per year approach of measuring compliance with the 24-hour particulate matter standard, instead of selecting the 98th percentile reading from the monitors, as currently proposed by the EPA.

There may be no safe level of exposure to ozone or particulate matter, so in the interest of public health, we need to strive to achieve the lowest level possible. Even at the lowest levels, children, the elderly, people who work and exercise outside, and people with heart and lung disease still feel the effects of air pollution. The EPA should set the standard at a level which protects all citizens in all areas of the United States, as mandated in the Clean Air Act.