WEDNESDAY, April 24 (HealthDay News) -- Although many Americans
are now breathing cleaner air, others are living in cities that are
more polluted than they were a decade ago, a new report shows.
"The long-term trend is positive and headed to much cleaner air," said report author Janice Nolen, assistant vice president of national policy and advocacy for the American Lung Association. "[However], there is an uptick in some areas that are a concern and some areas where the problem remains very, very serious."
The report, conducted by the American Lung Association, measured
the levels of ozone and small particles in the air, known as soot,
in almost 1,000 cities and counties in the United States between
2009 and 2011. About half of the 25 most polluted cities had
improved since last year's report, and many of those cities were
the cleanest they had been since the association began the research
Unfortunately, the other half of the 25 most polluted cities was
worse off. Even among the cities that improved, many were still
near the top of the most-polluted list, including Los Angeles,
which had the most ozone pollution, and Bakersfield, Calif., which
had the highest level of particle pollution.
In total, there were 254 counties with unhealthy levels of ozone
or particle pollution, and about 132 million people (42 percent of
the U.S. population) live in these areas. The previous report had
found that 127 million people (41 percent of the U.S. population)
resided in areas with poor air quality.
In addition to the California cities, Houston, Dallas, Oklahoma
City, Cincinnati, New York City and Washington, D.C., were among
the metropolitan areas that had high levels of ozone. As for
year-round levels of soot, many of the same cities in California
topped the list, as well as Cincinnati and Canton in Ohio;
Philadelphia and Allentown in Pennsylvania; Louisville, Ky.; St.
Louis; and Fairbanks, Alaska.
One expert was not surprised by the findings.
"Being from California, I knew we had a few pretty bad areas, but this report really drives it home," said Irva Hertz-Picciotto, a professor of environmental and occupational health at the University of California, Davis.
The cleanest cities, which did not have a single day of
unhealthy levels of ozone or particle pollution from 2009 to 2011,
were Bismarck, N.D.; Rapid City, S.D.; and the Fort Meyers and Palm
Beach areas of Florida.
A lot of it has to do with geography, Nolen said. Ozone, also
known as smog, forms when gases from car exhaust, coal-fired power
plants and other sources react with sunlight. In valley areas, like
around Los Angeles, these gases get trapped, whereas they are
dispersed quickly in elevated areas, she said.
The current report also listed more cities with unhealthy ozone
levels than the last report, which is probably explained by hotter
and sunnier weather, especially in the middle regions of the United
States, Nolen said.
In addition to geography and climate, "a lot of
transportation-related sources -- cars and trucks and shipping
ports -- contribute to [the ozone] problem in the California area,
and a lot of the most polluted cities in the eastern part of the
country have coal-fired power plants," Nolen said.
To reduce the level of smog-causing vehicle emissions, the
Environmental Protection Agency (EPA) proposed rules in March that
would require less sulfur in gasoline and stricter vehicle
emissions standards. Similar requirements went into effect in
California in 2012.
Although health and environmental groups and the automobile
industry support the proposal, oil companies oppose it, Nolen said.
"We are encouraging people to support the EPA rule," she added.
Nolen recommended that people keep track of the air quality in
their area through the
"If it is a high-alert day, drive less and don't burn wood or trash," she said.
Unfortunately, only about a third of counties in the United
States have air-quality monitors, because they are expensive to
install and collect, Nolen said. For the first time, however, this
year's report has information on every county, using data from
nearby cities and counties for areas that don't have their own
Both ozone and particle pollution can affect respiratory health,
worsening breathing and increasing the risk of asthma attacks,
respiratory infections and chronic obstructive pulmonary disease
"People thought problems were limited to the lungs, but over the past 15 years quite a bit of work has shown things like cardiovascular effects," Hertz-Picciotto said. Studies have found links between high levels of ozone and soot and increased risk of heart attacks and stroke, as well as lower birth weights and increased risk of infant mortality.
Air quality can have the biggest effect on vulnerable groups of
people, including young children, older adults and people with weak
immune systems, Hertz-Picciotto said.
You can find information about AIRNow and your local air quality
and air pollution in general at the
Association of Clean Air Agencies.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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