PREVALENCE AND PREDICTORS OF ASTHMA IN WORKING GROUPS IN BRITISH-COLUMBIA

We evaluated the prevalence of asthma and its predictors in studies of several male working groups: 619 cedar sawmill, 724 grain elevator, 3 99 pulpmill, 798 aluminum smelter, and 1,127 unexposed workers. These workers had taken part in health studies for assessment of chronic res piratory effects of various workplace exposures between 1979 and 1982. The American Thoracic Society Adult Questionnaire (ATS-DLD-78) was us ed for these studies. Allergy skin tests were also performed. The part icipation rates were > 80%. The overall prevalance of physician-diagno sed asthma was 4.6%, and current asthma 3%. The prevalence of asthma a fter employment in the current industry, as a surrogate for work-relat ed asthma, was 3.9 times higher in cedar sawmill workers, 2.2 times hi gher in pulpmill and aluminum smelter workers, and 1.7 times higher in grain elevator workers compared with unexposed workers. Atopy and a p ositive parental history of asthma, but not smoking, were important ri sk factors for asthma before the onset of first employment. Also, for asthma after employment in the current industry, atopy and a positive parental history of asthma were important risk factors. Smoking was as sociated with a significant reduction in the risk for asthma after emp loyment in the current industry. Within specific work groups, the prev alence of atopy was significantly higher among pulpmill workers with a sthma after employment in current industry than those without asthma. Conversely, cedar sawmill workers who had asthma after employment in t he current industry were nonatopic and nonsmokers. (C) 1995 Wiley-Liss , Inc.