Small Elevation in Ozone Levels Could Lead To Increase in Premature Deaths, Study Finds
Elevations in ozone levels could cause an increase in premature deaths, according to a study in the Journal of the American Medical Association, the Wall Street Journal reports.
In the study, which was funded by the Environmental Protection Agency, researchers from Yale and Johns Hopkins universities examined data from nonaccidental deaths in 95 urban areas in the United States between 1987 and 2000 and compared that data to ozone levels recorded in the same areas. Researchers then developed a statistical model to determine how a specific ozone increase would affect death rates.
Data analysis led researchers to project that an increase of 10 parts per billion of daily ozone in a week would cause at least 3,767 premature deaths in the 95 cities, largely from cardiovascular and respiratory complications. The "spikes in deaths weren't correlated with particularly high or low levels of ozone, but rather with upward changes in ozone," according to the Journal (Carlton, Wall Street Journal, 11/17). When ozone levels increased by 10 parts per billion over previous levels, daily deaths from noninjury over the next few days increased by an average of 0.52%, with cardiovascular and respiratory-related deaths increasing 0.64% and deaths among seniors increasing 0.70%, researchers found (Cone, Los Angeles Times, 11/17).
Researchers also found increased deaths with ozone spikes to levels below 80 parts per billion, the limit for what EPA considers "an acceptable level of ozone," according to the Journal (Wall Street Journal, 11/17). The analysis "ruled out" the possibility that heat, different kinds of pollution or other causes led to the deaths (Watson, USA Today, 11/17).
Michelle Bell, the study's lead investigator and assistant professor of environmental health at Yale, said the study found that mortality rates linked to ozone exposure were highest in New York City and Philadelphia. The study, which is "believed to be the first large-scale investigation of its kind in the United States to find a correlation between increases in ozone levels and premature deaths," will likely "place increased emphasis on reducing ozone, as well as alerting people to what they can do to protect themselves from adverse health effects," according to the Journal (Wall Street Journal, 11/17).
The study's findings "are likely to garner scrutiny from the EPA, which must decide in the next few years whether to hold counties to a more stringent smog goal," according to USA Today (USA Today, 11/17).
Bell said, "Now we can say that ozone has been linked to mortality in addition to other health concerns" (Berger, Houston Chronicle, 11/17).
Norman Edelman of the American Lung Association said, "This is a good, well-done study. It tells us something we've long suspected -- that ozone air pollution kills" (Seabrook, Atlanta Journal-Constitution, 11/16).
"The thing about air pollution is that everyone breathes the risk," Joel Schwartz of the Harvard School of Public Health said (Beil, Dallas Morning News, 11/17).
EPA officials said the study further supports the "need for continued state and federal efforts to reduce ozone levels," according to the Journal. Medical professionals said high-risk individuals -- including those with respiratory problems, seniors and children under 14 -- should avoid exercising outdoors and should "steer clear" of congested streets on smoggy days, according to the Journal (Wall Street Journal, 11/17).
NPR's "All Things Considered" on Tuesday reported on the study. The segment includes comments from EPA spokesperson Cynthia Bergman, Edelman, Arden Pope of Brigham Young University and Scott Zeger of Johns Hopkins School of Public Health (Aubrey, "All Things Considered," NPR, 11/16). The complete segment is available online in RealPlayer.This is part of the California Healthline Daily Edition, a summary of health policy coverage from major news organizations. Sign up for an email subscription.