. | . |
Ground-Level Ozone Linked To Increased Mortality
Baltimore MD (SPX) Nov 17, 2004 Changes in ground-level ozone were significantly associated with an increase in deaths in many U.S. cities, according to a nationwide study conducted by researchers at the Johns Hopkins Bloomberg School of Public Health and the Yale University School of Forestry and Environmental Studies. The risk of death was similar for adults of all ages and slightly higher for people with respiratory or cardiovascular problems. The increase in deaths occurred at ozone levels below the Environmental Protection Agency (EPA) clean air standards. The study appears in the November 17, 2004, edition of the Journal of the American Medical Association (JAMA.) Ground-level ozone is a pollutant in the Earth's lower atmosphere that is formed when emissions from cars, power plants and other sources react chemically to sunlight. Stratospheric ozone, which is higher in the atmosphere, is the "ozone layer" that protects the Earth from ultraviolet radiation. "This is one of the largest ozone pollution studies ever conducted," said lead author Michelle Bell, PhD, who was previously with the Bloomberg School of Public Health and is now an assistant professor at the Yale School of Forestry and Environmental Studies. The ozone study was part of the ongoing National Morbidity Mortality and Air Pollution Study (NMMAPS) at the Bloomberg School of Public Health, which routinely assesses health effects of air pollution on a national scale. To determine the association between ozone and mortality, the researchers looked at the total number of non-injury-related deaths and cardiovascular and respiratory mortality in the 95 largest U.S. communities from 1987 to 2000. Air pollution data were supplied by the EPA. Mortality data were supplied by the National Center of Health Statistics. The researchers accounted for variables such as weather, particulate matter pollution and seasonality, which could impact mortality rates. The researchers found that an increase of 10 parts per billion (ppb) in weekly ozone levels was associated with a 0.52 percent daily increase in deaths the following week. The rate of daily cardiovascular and respiratory deaths increased 0.64 percent with each 10 ppb increase of weekly ozone. The average daily ozone level for the cities surveyed was 26 ppb. The EPA's maximum for ground-level ozone over an 8-hour period is 80 ppb. The researchers calculated that a 10 ppb reduction in daily ozone, which is roughly 35 percent of the average daily ozone level, could save nearly 4,000 lives throughout the 95 urban communities included in the study. "Our study shows that ground-level ozone is a national problem, which is not limited to a small number of cities or one region. Everyone needs to be aware of the potential health risks of ozone pollution," said Francesca Dominici, PhD, senior author of the study and associate professor in the Department of Biostatistics at the Bloomberg School of Public Health. The data and statistical models used to complete the study are available on the Health and Air Pollution Surveillance System website at www.ihapss.jhsph.edu. The site is maintained by the Johns Hopkins Bloomberg School of Public Health and sponsored by the Health Effects Institute. "Ozone and Short-Term Mortality in 95 U.S. Urban Communities, 1987-2000" was written by Michelle L. Bell, PhD; Aidan McDermott, PhD; Scott L. Zeger, PhD; Jonathan M. Samet, MD; and Francesca Dominici, PhD. Related Links Johns Hopkins Bloomberg School of Public Health Yale University School of Forestry and Environmental Studies SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Climate: Humans Fuss, Animals Adjust Boulder CO (UPI) Nov 15, 2004 Scientists can argue all they want about how many degrees Celsius - or Fahrenheit - the planet is warming and what the trend portends, but meanwhile Earth's plants, insects and animals are not waiting for the outcome. They already are altering their patterns of behavior in response to what is happening. |
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |