Pulmonary function profiles in Quebec asbestos workers.

Lung function profiles were defined in over 1,000 Quebec chrysotile asbestos workers using five standard tests of lung function, and were related to dust exposure and smoking. Close to half the men (44.3%) had a normal lung function profile and a further 26.5% some function changes but no definite profile. Amongst the remainder restrictive and obstructive function profiles occurred with equal frequency (12.8 and 12.2% respectively). Both were associated with radiologic asbestosis; both occurred infrequently in the absence of the smoking habit. These findings suggest an association between the smoking habit and the harmful effects of asbestos exposure on lung function, and by implication on the development of lung fibrosis. A similar association has been recognized in respect of bronchogenic carcinoma. This experience, in the primary mining and milling of pure chrysotile asbestos, may not be directly applicable to secondary industries concerned with the further processing of this fibre.