Abstract
Epidemiological studies of aluminum potroom workers have been in progress in Norway since 1986. The occurrence of work-related asthmatic symptoms and their determinants were studied. Work-related asthmatic symptoms and airflow limitation were closely associated with duration of potroom employment. A significant relationship between current fluoride exposure and work-related asthmatic symptoms was observed in a smaller, cross-sectional population where a detailed exposure classification was carried out. A similar association and also a dose-response gradient was found in a longitudinal study of new employees. The existence of occupational asthma in aluminium potroom workers was confirmed by characteristic patterns of repeated peak flow measurements supported by changes in methacholine responsiveness in workers with suspected work-related asthma. Current smoking as a risk factor for work-related asthmatic symptoms was observed both in cross-sectional and in longitudinal investigations. Similarly to current fluoride exposure, a dose-response gradient was demonstrated in the association between work-related asthmatic symptoms and current amount of tobacco smoked. Allergy was not shown to be a determinant of work-related asthmatic symptoms in any part of the investigation. A family history of asthma and previous occupational exposure may have had some influence on the risk of developing symptoms but the findings were inconsistent and probably of minor importance. Methacholine challenge seemed inappropriate for the screening of aluminium potroom workers in order to detect work-related asthmatic symptoms, but was closely correlated to the severity of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)