The study looked at hospital discharges for people with these four types of diseases living in 34 cities between 1985 and 1999. The researchers compared this information with 12-month averages of PM10, a type of particulate matter air pollution that includes particles with a diameter of 10 micrometers or less than 0.0004 inches or one-seventh the width of a human hair.
The study found that for an increase of 10 micrograms/per cubic meter of PM10 over two years, the risk of dying was increased by:
"The study significantly strengthens evidence that breathing in particulate matter is associated with dying sooner," said researcher Joel Schwartz, Ph.D., Professor of Environmental Epidemiology at the Harvard School of Public Health in Boston.
"While previous studies have found that long-term exposure to air pollution is associated with increased risk of death, we looked at risk of death in the first three years after patients were discharged from the hospital, and saw that the risk increased in the first couple of years. That means if we can lower air pollution levels, people will start living longer right away--we don't have to wait many years to see health improvements. That wasn't clear from previous air pollution studies."
Technology that can reduce particulate matter levels already exists, Dr. Schwartz noted. "For instance, we know how to put scrubbers on
Contact: Jim Augustine or Bill Glitz
American Thoracic Society