Tiny particles in air linked to 1,000 early deaths in San Diego

San Diego's particle pollution ranks as the thirteenth worst in the United States

provided by Environmental Health Coalition
iny particles in the air contribute to an estimated 1,000 premature deaths annually in San Diego, according to a new analysis by the Natural Resources Defense Council (NRDC) released in May. The study is the first ever estimate of the number of heart and lung-related premature deaths from fine particle air pollution in U.S. metropolitan areas.
The study finds that the majority of urban areas in California experience more than 300 particulate related air pollution deaths each year, even at pollution levels well below the current national health standard. San Diego County is currently in compliance with the federal particulate matter standard, but all areas of San Diego County where air quality is measured are out of compliance with the more stringent California 24-hour particulate standard.

New standards

"What this report shows is that current levels of fine particle pollution are a serious threat to the public health. Hundreds of premature deaths in San Diego could be averted each year if the EPA set stringent new health standards for fine particle pollution," said Paula Forbis of the Environmental Health Coalition, which released the study in San Diego. "In addition to that, we call upon the local Air Pollution Control District to enforce all current regulations that apply to particulates and resist pressure to relax these standards."
Currently the APCD is considering whether to roll back emission standards for certain types of road paving equipment which emit fine particles. For some of these types of equipment, control technology has been developed and is already in use. "We see no reason why standards should be rolled back to appease some members of industry, when conscientious members of the industry are in compliance with the current standards," Forbis continued.
The report, entitled BREATH-TAKING: Premature Mortality Due to Particulate Air Pollution in 239 American Cities, reviews the mass of epidemiological studies on the health effects of particulate pollution. The report covers a total of 239 U.S. Metropolitan Statistical Areas. Cities that ranked at the top of the list in terms of particulate air pollution-attributable deaths were Los Angeles, New York, Chicago, Philadelphia, and Detroit. San Diego ranked thirteenth.
The NRDC report estimates that approximately 64,000 people may die prematurely each year as a result of particulate air pollution. Lives are shortened by an average of one to two years in the more polluted areas. The elderly and those with heart and lung disease are most affected. The study also noted that other measures of respiratory distress, such as asthma attacks, use of bronchodilators, and trips to the emergency room, are linked to particulate levels. "The analysis shows that the current health standards for particulate matter are not protective of public health," said Deborah Sheiman Shprentz, author of the NRDC report.
The NRDC report is the first to apply the findings of a 1995 study by the American Cancer Society (ACS) and Harvard Medical School to local data to gauge the extent of the particle pollution problem. The ACS study reported that people living in cities with higher concentrations of fine particles suffered an increased risk of premature death, compared to people living in cleaner cities. The ACS study used statistical techniques to factor out the effect of other risk factors such as smoking, body weight, occupational exposure and other air pollutants.
The findings come at a time when EPA is reexamining its health standards for particulate air pollution. The analysis show that EPA needs to select more stringent standard levels than those now under consideration in order to substantially reduce premature deaths from particulate air pollution. NRDC and EHC are recommending that EPA establish a new standard for the fine particles (PM2.5) at a level of 10 micrograms per cubic meter on an annual average basis, lower the annual average PM10 standard to 17 micrograms per cubic meter, and establish stringent new limits on 24-hour concentrations.
According to data from the National Center for Health Statistics, 8,147 adults died from cardiopulmonary causes in the San Diego metropolitan area in 1989. The NRDC report estimates that particulate air pollution plays a role in about 1,000 of these deaths.

More than meets the eye

Particulate air pollution is not just visible smoke and soot; it is also made up of tiny invisible particles formed from gaseous emissions of sulfur dioxide and volatile organic compounds. These tiny particles are considered to be the most dangerous by health scientists because they are small enough to evade the body's respiratory defense mechanisms and lodge deep in lung tissue. Current standards do not target fine particle pollution.
The NRDC study examines the primary sources of particulate pollution nationally, including older, coal-fired power plants, industrial boilers, and gas and diesel-powered vehicles, among others, and recommends solutions for reducing the emissions from these sources. Local sources of particulate pollution include gasoline vehicle exhaust, diesel vehicle exhaust, power generation, solvent use in local industries, and operations of the construction and mineral products industries.
A limited number of copies of the report are available from the Environmental Health Coalition (235-0281).