RESPIRATORY CANCER INCIDENCE IN SWEDISH CONSTRUCTION WORKERS EXPOSED TO MAN-MADE MINERAL FIBRES AND ASBESTOS

Abstract

The incidence of respiratory cancer has been studied in relation to exposure to man-made mineral fibres (MMMF) within a large cohort of Swedish construction workers. The cohort comprised some 135 000 men, who were all examined by Bygghälsan at regular health check-ups in 1971–1974. The cohort has been followed for mortality through 1983 and for cancer incidence through 1982 by linkage to various national registries. A case-control study within the cohort has been carried out on 518 cases diagnosed as having respiratory cancer. For each case, five controls were selected among those who had not developed such a cancer with individual matching for age and year of first check-up. Subjects selected have been classified into categories based on self-reported exposure and on estimates of average intensity of exposure in occupations concerned. In the analysis smoking habits and density of population in parish of residence were included as potential confounders. Results of an analysis of the incidence of pleural mesothelioma in relation to exposure indicates that subjects in the cohort to some extent are unaware of their exposure to asbestos. The strong association between asbestos exposure and MMMF exposure makes it difficult to separate effects of the two exposures. The results, however, appear compatible with the known effect of asbestos exposure on lung cancer incidence. Subjects classified as heavily exposed to MMMF do not have a significantly higher incidence than unexposed subjects.