Air pollution and exacerbation of asthma in African-American children in Los Angeles

Significant increases in asthma morbidity and mortality in the United State s have occurred since the 1970s, particularly among African-Americans. Expo sure to various environmental factors, including air pollutants and allerge ns, has been suggested as a partial explanation of these trends. To examine relations between several air pollutants and asthma exacerbation in Africa n Americans, we recruited a panel of 138 children in central Los Angeles. W e recorded daily data on respiratory symptoms and medication use for 13 wee ks and examined these data in conjunction with data on ozone (O-3) nitrogen dioxide (NO2), particulate matter (PM10 and PM2.5), meteorological variabl es, pollens, and molds. Using generalized estimating equations, we found as sociations between respiratory symptom occurrence and several environmental factors. For example, new episodes of cough were associated with exposure to PM10 (OR = 1.25; 95% CI = 1.12-1.39; interquartile range [IQR] = 17 mug/ m(3), 24-hour average), PM2.5 (OR = 1.10; 95% CI = 1.03-1.18; IQR = 30 mug/ m(3), 12-hour average), NO2, and the molds Cladosporium and Alternaria, but not with exposure to O-3 or pollen. The factors PM10 and O-3 were associat ed with the use of extra asthma medication. For this population several bio aerosols and air pollutants had effects that may be clinically significant.