Cigarette Smoking, Occupational Dust Exposure, and Ventilatory Capacity

Abstract

Among older men who had been exposed for many years to hemp dust in industry, the relations between ventilatory capacity (as measured by FEV_1.0) and cigarette-smoking habits appeared to be affected by a process of self-selection. Active 50 to 69-year-old, moderate to heavy smokers had a significantly higher FEV_1.0 than non-smokers or light smokers. Of all men in this age group 26% were ex-smokers, with a low mean FEV_1.0. Hemp workers of all smoking categories had a low FEV_1.0 in comparison to similar controls. The chronic effect of hemp-dust exposure on FEV_1.0 appears to be a main factor in determining who gave up smoking (ie, those who were affected by long-term hemp-dust exposure) and who still smoked. In epidemiological surveys, the relations between lung function results and smoking habits may be contrary to expectation if effects of concurrent exposures to other inhaled noxious agents influence the smoking habits of the subjects.