Lung cancer and mesothelioma in the pleura and peritoneum among Swedish insulation workers

Objectives-To estimate the risk of cancer and death in Swedish insulation workers some years after their exposure to asbestos had stopped. One hypothesis was that the risk of lung cancer would tend to decrease some years after the exposure had ended. Methods-In a cohort study the cancer morbidity and cause of death was investigated in 248 insulation workers and compared with the corresponding morbidity and mortality in the general population. Due to stringent regulations, exposure to asbestos of all types had almost ended in Sweden in the mid-1970s. Through a questionnaire, surviving insulation workers were asked about their exposure to asbestos and their smoking habits. Results-Between 1970 and 1994 there were 86 deaths compared with the 46.0 expected (standardised incidence ratio (SIR) 1.93 95% confidence interval (95% CI) 1.5 to 2.3), the increase was mainly due to an increased cancer mortality. The morbidity was increased for lung cancer (11 cases v 2.5 expected (SIR 4.4; 95% CI 2.2 to 7.9)), peritoneal mesothelioma (seven cases; no expected incidence could be calculated as the occurrence is too rare in the general population), cancer in pancreas (five cases v 0.7 expected (SIR 7.1; 95% CI 2.3 to 16.7)). No cases of pleural mesothelioma were found. The risk of lung cancer did not tend to approach that of the general population after the exposure to asbestos decreased. Conclusions-In the 1980s and the early 1990s, Swedish insulation workers still have a highly increased risk of diseases related to asbestos, The attributable risk. for death and cancer was about 50%. The study also confirms the previous finding that mesothelioma in insulation workers seems to be situated in the peritoneum more often than in the pleura.