By LEE BOWMAN
Scripps Howard News Service
April 25, 2008
There's plenty of polluted air to create some dangerous health consequences for people of all ages right in our own backyards.
A steady stream of research sounds the alarms. Just this month, scientists have linked air pollution levels to asthma symptoms and school absences among inner-city kids, increased the number of deaths from pneumonia and premature death from even short-term exposure to ozone pollution, the major component of smog. Bad air even robs people of the pleasure of flowers and honey.
Many other studies have shown a connection between short and long-term exposure to air pollution and the risk of heart attack, abnormal heart rhythms, heart failure and stroke. The danger is present not only for people already suffering from heart disease, but also even for young fit people with no heart problems.
European scientists recently found that even short exposure to diluted diesel exhaust fumes while exercising reduced levels of a substance in the blood that prevents clots from forming. That can lead to an impaired flow of blood and oxygen to the heart, which can in turn trigger a heart attack.
The asthma study, led by Dr. George O'Connor of the Boston University School of Medicine, followed more than 850 children living in low-income areas of Boston, New York City, Chicago, Dallas, Seattle and Tucson.
O'Connor and his colleagues found that asthma symptoms and asthma-related school absences increased whenever there were higher concentrations of pollution -- nitrogen dioxide, sulfur dioxide and fine particulate matter, among others. The study appeared in the April issue of the Journal of Allergy and Clinical Immunology.
Researchers at the University of Birmingham in England looked at deaths from a variety of causes in 352 localities and traced pollution levels from 1996 through 2004. They found that pneumonia deaths were strongly linked to emissions levels, particularly from burning oil or gas.
There were 54,000 pneumonia deaths in 35 heavily polluted jurisdictions, about 15,000 more than should have otherwise occurred in those communities over the eight years, Prof. George Knox and colleagues report in Journal of Epidemiology and Community Health.
Finally, the National Research Council of the National Academies of Sciences tackled the connection between short-term ozone exposure and the risk of death.
The report said the evidence that such exposures contribute to premature deaths is strong enough that the Environmental Protection Agency should take ozone-related mortality into account when setting future air pollution standards.
While the risk is greater for people with pre-existing diseases and other factors that increase their susceptibility, the committee noted the threat is not limited to only those individuals.
Ozone is an airway irritant that can cause inflammation, reduce lung capacity and cause permanent lung damage and susceptibility to respiratory illness even in healthy people. In people with asthma, it can trigger asthma attacks.
But urban air pollution is typically such a cocktail of chemicals that it produces some effects over several days and others, like an effect on heart rate and blood pressure, almost immediately.
One study reported last year by researchers in Taiwan found impact from pollution on a group of 18 to 25-year-old students within one to three days.
Now about the flowers and honey.
Researchers at the University of Virginia reported this month that air pollution from power plants and autos can cut the ability of pollinating insects to follow scent trails to their source by as much as 90 percent.
A team led by Joe Fuentes, a professor of environmental scientists, calculated that in more heavily polluted areas, a bee has to get within a few football field lengths of a flower to pick up scent molecules before they are overwhelmed by pollution, while in more pristine air, they can find the same flower from more than a half-mile away.
The result, Fuentes and his team write in the journal Atmospheric Environment, is that the pollinators fail to find enough nectar to sustain their populations, while flowering plants don't get pollinated sufficiently to thrive.
This could be at least part of the reason that populations of bees, as well as many butterflies, have declined in recent years in many parts of the U.S. and other parts of the world, the researchers said.
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