Air pollution had been linked to health hazards before but a recent research suggests that experts may be underestimating the deaths caused by air pollution. The study shows that pollution's chronic health effects are two to three times greater than earlier believed.
The study appears in the online issue of Epidemiology.
According to researchers of the University of Southern California, among the participants of the study, for each increase of 10 micrograms per cubic meter (µg/m3) of fine particles in the neighborhood's air, the risk of death from any cause rose by 11 to 17 percent, and the paper's lead author. Fine particle levels can differ by about 20 µg/m3 from the cleanest parts of Los Angeles city, where the study was done, to the most polluted.
The results show that ischemic heart disease mortality risks rose by 25 to 39 percent for the 10 µg/m3increase in air pollution.
Earlier studies took one or two pollution measures from several cities and compared health effects among cities. This study digs more deeply, taking pollution measures at 23 sites within Los Angeles to more accurately reflect air pollution exposure where residents live and work.
Researchers examined data from 22,906 residents of Los Angeles, Riverside, San Bernardino and Ventura counties in the American Cancer Society's Cancer Prevention Study II since 1982. They determined air pollution exposure in 267 different zip codes where participants lived. The vast number of participants allowed scientists to control for dozens of factors that influence health outcome, such as smoking, diet and education. Finally, they compiled causes of death for the 5,856 participants who died by 2000.