Smog May Cause Asthma in Healthy Children, Study Finds

Children who play sports and reside in smoggy communities develop asthma at triple the rate of children who live in communities with cleaner air, according to a new study conducted by University of Southern California and government researchers. The Los Angeles Times reports that the study, part of a 10-year, $18 million children's health research project at USC, is the "first to show that smog can cause the sickness in otherwise healthy kids." In the study, which will appear in the Lancet tomorrow, researchers from USC, the California Air Resources Board and the National Institute of Environmental Health Sciences tracked 3,535 California children in the fourth, seventh and 10th grades in seven smoggy communities and six communities with cleaner air from 1993 to 1998. None of the children had a history of asthma, respiratory disease, wheezing, chest injuries or surgery. Researchers also accounted for socioeconomic status, history of allergies and family history of asthma (Polakovic, Los Angeles Times, 2/1). Over five years, researchers identified 264 new cases of asthma (Kay, San Francisco Chronicle, 2/1). Children who played three or more sports across the 13 communities were 80% more likely to develop asthma than those who were less active, but that rate increased to 330% in smoggy communities, the study found. Researchers found "little or no effect" caused by strenuous sports on the asthma rate among children in communities with "little or no pollution." Researchers said that children in smoggy communities nationwide -- such as Houston, Atlanta and Phoenix -- may "face similar risks" of asthma (Los Angeles Times, 2/1). "We've made a lot of progress in decreasing air pollution across the United States, but our study and a variety of other studies suggest there are still hazards to children from air pollution," lead author Rob McConnell of USC's Keck School of Medicine said.

Some scientists, however, "suggested caution" about the results of the USC study. C. Arden Pope, a researcher on air pollution and health at Brigham Young University, said, "If it's true, it's a very important finding. But I wouldn't say it's definitive" before the findings have been replicated (Watson, USA Today, 2/1). In addition, Scott Weiss, director of respiratory, environmental and genetic epidemiology at Harvard Medical School, said that many of the children in the study may have suffered from asthma "all along but did not know it" (Borenstein, Philadelphia Inquirer, 2/1). About nine million children worldwide suffer from asthma (Booth, Washington Post, 2/1).