Anaheim - Airborne levels of total suspended particulates (TSP) are directly related to 60,000 deaths per year in the United States, according to a study by the US Environmental Protection Agency (EPA). The study is considered to be the most precise, detailed quantification yet made of air pollution's toll on public health. The victims are most likely to be older patients with pre-existing respiratory and cardiovascular diseases.

"Of course, these aren't healthy people who just walk out on to the street and drop over dead from the air pollution," said EPA senior scientist Dr. Joel Schwatts (PhD). "On the other hand, we're also not talking about people who would have died days or weeks later anyway. whether there was heavy air pollution or not."

For example, excess deaths were seen among pneumonia patients who might have recovered to live several more years were it not for high concentrations of TSP. Likewise, many heart disease patients and individuals with flare-ups of chronic obstructive pulmonary disease (COPD) would have likely recovered given more favorable breathing conditions.

"The air pollution is an additional stress on the body and it's the final straw for these patients," said Dr. Douglas Dockery (PhD), an associate professor at the Harvard School of Public Health, who co-authored the study with Dr. Schwaru. In their presentation here to the International Conference of the American section, the American Thoracic Society (ATS), the authors said previous multicity studies failed to take into account many variables, such as patterns of cigarette smoking and industrial exposures.

The new study sought to remedy this by focusing on a major U.S. city, Philadelphia, which is one of the few cities that daily measure TSP, such as smoke, fumes, dusts, aerosols and microorganisms generated by environmental and industrial sources. Correlation TSP levels were compared with seven years of death records for Philadelphia. There was a significant correlation between total mortality and air concentrations of TSP. When corrected for other variables, analysis showed that deaths increased by an average of 79% with an increase of 100 micro-grams per cubic meter TSP, with the greatest increase in deaths seen in individuals over 65.

There was a trend toward increased mortality in people of all ages with COPD (including emphysema and chronic bronchitis) and pneumonia. For individuals with cardiovascular disease, there was a statistically significant 10% increase in mortality. The increased deaths in this study are being seen at levels of TSP that are less than one-half the current acceptable levels." said Dr. Schwartz.