The air pollution really has relation with dying

The air pollution really has relation with dying
NEW YORK (Reuters Health) -A new study in 20 of America's largest cities has linked exposure to common pollutants from cars and factories to an increased risk of death. The study, published in the December 14th issue of The New England Journal of Medicine (news - web sites) ,suggests that the more polluted a city is, the more likely its residents are to die from disease. Specifically, every time the level of particulate matter smaller than 10 micrometers in diameter increased by 10 mi crograms per cubic meter in large cities like New York and Atlanta, there was a 0.51% increased risk of death from all causes. Cardiopulmonary mortality rates --that is, death from heart or lung diseases --were 0.68% higher for each 10 microgram per cubic meter increase. Researchers took pollution measurements in large metropolitan areas in all regions of the country and then tried to correlate the samples with daily death rates in each of the cities. They picked so-called"small particle" pollutants, including ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide, since those are thought to be the most dangerous to humans. Other studies have placed the increased death risk from pollution exposure as high as 1%. No one knows exactly why pollution is toxic to humans, though many experts suspect that pollutants cause inflammation in the lungs or cause the body to rele ase chemicals that can affect heart function. The investigators tried to account for confounding factors that could blur the study's results. For instance, they controlled for some measures of socioeconomic status, since it is likely that poorer people, who tend to also have poorer health, live in areas with more polluting cars and factories. It is also possible that people who live in high-traffic cities have higher death rates due to traffi c accidents and not necessarily pollution. "There are many different factors in cities and we can't control for all of them, "lead investigator Dr. Jonathan M. Samet, told Reuters Health in an i nterview. Still, the authors conclude that so-called"small particle" pollution, like the kind studied here, needs to be strongly limited through the Environmental Protection Agency (EPA) . An EPA regulation to strengthen pollution limits is currently under review by the Supreme Court, with a decision expected this spring. "From a public health view, we need a stronger EPA standard for particulate matter, "said Samet, who is the chief epidemiologist at the Johns Hopkins School of Public Health in Baltimore, Maryland. SOURCE: The New England Journal of Medicine 2000; 343:1742-1749.

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