Air Pollution Found To Pose Greater Danger To Health Than Earlier Thought

LOS ANGELES (Sept. 20)-Experts may be significantly underestimating air pollution's role in causing early death, according to a team of American and Canadian researchers, who studied two decades' worth of data on residents of the Los Angeles metro area.

When the epidemiologists examined links between particle pollution and mortality within more than 260 Los Angeles neighborhoods, they found that pollution's chronic health effects are two to three times greater than earlier believed. The study appears in the November issue of Epidemiology but was published early on the journal's Web site.

Among participants, 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, according to Michael Jerrett, Ph.D., associate professor of preventive medicine at the Keck School of Medicine of the University of Southern California and the paper's lead author. Fine particle levels can differ by about 20 µg/m3 from the cleanest parts of Los Angeles to the most polluted.