Pesticide use and chronic bronchitis among farmers in the agricultural health study

Background Farmers have increased risk for chronic bronchitis. Few investigators have considered pesticides. Methods We evaluated pesticides as risk factors for chronic bronchitis using the Agricultural Health Study enrollment data on lifetime pesticide use and history of doctor-diagnosed chronic bronchitis from 20,908 private pesticide applicators, primarily farmers. Results A total of 654 farmers (3%) reported chronic bronchitis diagnosed after age 19. After adjustment for correlated pesticides as well as confounders, 11 pesticides were significantly associated with chronic bronchitis. Heptachlor use had the highest odds ratio (OR = 1.50, 95% Confidence Interval (CI) = 1.19, 1.89). Increased prevalence for chronic bronchitis was also seen for individuals who had a history of a high pesticide exposure event (OR = 1.85, 95% CI = 1.51, 2.25) and for those who also applied pesticides in off-farm jobs (OR = 1.40, 95% CI = 1.04,1.88). Co-morbid asthma and current farm activities did not explain these results. Conclusions These results provide preliminary evidence that pesticide use may increase chronic bronchitis prevalence. Am. J. Ind. Med. 50:969-979,2007. (c) 2007 Wiley-Liss, Inc.