Study Links Smog to Long-Term Lung Damage

      LOS ANGELES -- In the most convincing evidence yet that smog retards children''s lung growth, a new study shows that dirty air can lead to long-term and possibly irreversible health problems, University of Southern California researchers found.

      In a study to be released Thursday, the researchers reported that ozone -- for decades the nation''s main indicator of the severity of air pollution -- is not the cause of long-term health impact.

      The study -- the first to follow a large group of children through years of development -- correlated levels of specific types of pollutants -- ozone, nitric and hydrochloric acids, nitrogen oxides and particulates -- with lung capacity growth in children in Lancaster, San Dimas and 10 other Southern California communities.

      ``We''ve known for years that air pollution can cause acute problems, like coughing, watery eyes, tightness in the chest,'' said James Gauderman, assistant professor of preventive medicine at USC''s Keck School of Medicine. ``Prior to this study, we really didn''t know if there were chronic effects that were long term in nature and perhaps irreversible.''

      The study, to be published in the October issue of the American Journal of Respiratory and Critical Care Medicine, recruited classes of about 3,600 fourth-, seventh- and 10th-graders in 12 communities. The researchers measured the children''s lung capacity from 1993 through 1997 and compared the measurements with those of children in three relatively smog-free communities north of Santa Barbara, Calif.

      The effects were noticed mainly in the 1,800 studied fourth-graders, who are now high school seniors and are still being monitored for additional results to be reported later.

      ``It doesn''t look like the decrease in lung function growth that we observed in the fourth-grade group is likely to be reversed based on our observation of the seventh- and 10th-grade groups,'' Gauderman said.

      Previous studies had shown a link between reduced lung capacity and living in smoggy Southern California, but the new study found that lung capacity growth of children in the most polluted community, San Dimas, was about 10 percent lower than their peers in relatively clean communities. Lung capacity growth for children in Lancaster, which has moderate amounts of most pollutants, was about 6 percent lower than those in the control group.

      ``We have always in the past estimated that living in highly polluted areas, a person could easily suffer 5 percent loss in lung function over their lifetime,'' said Jerry Martin, a spokesman for the California Air Resources Board, which paid for most of the study.

      A 10 percent loss, according to the agency''s health experts, could well decide whether a person suffering an asthma attack would need hospitalization or not.

      While it was difficult to sufficiently distinguish most types of pollution to determine their individual impacts, the researchers were surprised by what they found in the mountain community of Lake Arrowhead.

      Since air quality authorities have monitored air pollution, such high-elevation communities in the eastern end of the Inland Empire have shown the nation''s greatest levels of ozone. Lake Arrowhead was unique in that it has high ozone levels, but low levels of other pollutants. Children there showed a lung capacity growth of more than 12 percent a year, nearly as high as those in the nonsmog communities.

      By contrast, the eastern Los Angeles County community of San Dimas showed only 11 percent growth per year, and had high levels of all pollutants, including the highest of all communities in nitric and hydrochloric acids.

      In addition to Lancaster, Lake Arrowhead and San Dimas, the communities studied were Alpine, Lake Elsinore, Long Beach, Mira Loma, Riverside and Upland. The control communities were Atascadero, Lompoc and Santa Maria.

     

c.2000 Los Angeles Daily News