"It has proven difficult to figure out which is most toxic," explained Michael Jerrett, a professor of environmental health sciences at University of California, Berkeley.
Instead, researchers tend to think a mix of pollutants that includes particulate matter, carbon and nitrogen dioxide are the most dangerous. "If we were to reduce carbon dioxide, we are going to get benefits in terms of reduced levels of other pollutants that are strongly associated with health effects," Jerrett explained.
"Showing that you can achieve these major [pollution] reductions if you are willing to put these controls in place is an important finding in and of itself," Jerrett added.
Previous research has found that decreases in particulate matter in the United States during the 1980s and 1990s were responsible for 15 percent of the increase in life expectancy during this period.
A lot of the pollution-control measures undertaken by the United States and other wealthy industrialized countries for the past 30 years were "low-hanging fruits, and measures now are quite costly," Jerrett added. "People making these decisions want to have certain evidence, and I think this study adds to the body of evidence of the potential health benefits."
To learn more about local air quality and health risks, visit State of the Air 2012.
SOURCES: Junfeng (Jim) Zhang, Ph.D., professor, environmental and global health, Keck School of Medicine, University of Southern California, Los Angeles; Michael Jerrett, Ph.D., chair, professor, environmental health sciences, School of Public Health, University of California, Berkeley; May 16, 2012, Journal of the American Medical Association
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