BIRMINGHAM, Alabama -- Birmingham's air quality continues to improve but still ranks among the most polluted in the country, according to the American Lung Association's 2011 State of the Air report, which is being released today.
In its 12th annual report, the Lung Association ranks the city eighth-worst on measures of fine particle pollution for the period between 2007 and 2009, which was better than the fifth place ranking in 2010. The city dropped to 21st in the association's ranking of the most ozone-polluted cities, improving from 19th in 2010.
Birmingham's gains come in the context of widespread improvement in the nation's air quality because of federally mandated pollution controls. "The State of the Air clearly shows us that the Clean Air Act is working," said Janice Nolen, an assistant vice president for the association.
However, association officials also warned that progress is endangered by several congressional proposals they said would weaken the Clean Air Act or block the EPA's ability to enforce it.
Birmingham's rankings should improve further because the association's rankings include 2007, when a lack of rain and forest fires in south Georgia kept pollutant levels high locally. The Birmingham region in 2009 and 2010 had no orange air quality alert days for particle pollution, a designation that indicates air is unhealthy for sensitive groups.
Despite state and local officials saying Birmingham's air quality now meets the federal standards, the Lung Association contends the federal standards allow levels of pollution that are now known to be harmful to health.
New more protective air quality standards, which have been long-delayed, are expected to go into force later this year, and local officials concede it will take more pollution fighting measures to meet them. The new standards are based on a better scientific understanding of the effect that pollution can have on developing lungs and long-term health.
"The existing standard is way too lenient. It needs to be much lower," Nolen said.
According to the Lung Association, air pollution is especially harmful to the young, the elderly and those with respiratory disease and asthma. People living in poor neighborhoods near industrial sites or near heavily traveled highways also tend to be disproportionately affected by air quality problems.
Ozone pollution causes inflammation of airways, and particle pollution can irritate airways, decrease lung function, aggravate asthma, and cause heart problems and premature death in people with heart or lung disease.
"As research increases, the negative health effects of air pollution are much greater than we previously thought," said Dr. Norman H. Edelman, the Lung Association's leading medical authority.
Ron Gore, the chief of the Alabama Department of Environmental Management's air division, said particle pollution in the state comes from three principle sources. About 40 percent comes from sulfates and nitrates produced by coal-fired power plants; 40 percent is soot from automobile tailpipes, open burning and forest fires, and 20 percent is from dirt and salt air.
Air quality also is influenced by the weather -- cold days can keep particle pollution trapped close to the earth's surface and hot days stimulate the formation of ozone. Economic conditions also have an effect, with more pollution generated when the economy is humming.
Some of the pollution comes from local sources, but about 70 percent to 75 percent of the airborne pollutants blow in from other sources in the region, Gore said. The Lung Association's Nolen said that movement of pollution underlines the importance of having a strong national air pollution enforcement program.
"EPA is the only agency that can help with that," Nolen said.