EPIDEMIOLOGIC HEALTH SURVEY OF GRAIN ELEVATOR WORKERS IN BRITISH-COLUMBIA

Abstract

Epidemiologic health surveys were carried out among 610 workers in the 5 grain elevators in British Columbia and 2 control groups consisting of 136 civic workers and 187 non-cedar sawmill workers. A medical and occupational questionnaire was administered by trained interviewers. Spirometry was performed on site using a 13.5-l Collins spirometer. Skin tests were performed using various antigens and serum samples were obtained for determination of .alpha.1-antitrypsin concentration and phenotype, and precipitin studies. Dust concentration was measured by both personal and area sampling methods in the grain elevators and sawmills. There was a higher prevalence of eye, nasal and chest symptoms (cough, sputum, wheeze and breathlessness) among grain workers than among control subjects. The mean values for spirometric indices of pulmonary function (forced expiratory volume in 1 s and forced vital capacity) were slightly lower among grain workers than control subjects. The estimated decreases in forced expiratory volume in 1 s, forced vital capacity and forced expiratory flow during the middle half of the forced vital capacity with age were also greater for grain workers than control subjects. The mean pulmonary function test results improved during the work week among sawmill workers but decreased during the work week among grain workers, suggesting that grain dust has acute deleterious effects on pulmonary function in some workers. Regardless of the work group, current smokers had more chest symptoms and lower pulmonary function test results than ex-smokers and nonsmokers. No potentiating effect of smoking and exposure to grain was demonstrated. There was no correlation between the duration of employment in the grain elevator and deterioration of respiratory function.