Search

Objectives: To estimate the risk of cancer due to occupational exposure to petroleum products in the Swedish transport and refinery industries.Methods: In a retrospective cohort study the cancer incidence in 4128 men and 191 women, who had worked for at least one year in the petroleum industry, was compared with the incidence in the general population. The job titles and employment times for each person were found in personal files in the industries. The men had on average worked in jobs exposed to petroleum for 11.6 years at the end of the observation period. The cases of cancer were identified by record linkage with the Swedish cancer register.Results: In total there were 146 cases of cancer v 157.6 expected (standardised mortality ratio (SMR) 0.93 90% confidence interval (90% CI) 0.80 to 1.1). Operators at refineries had an increased risk of leukaemia (6 cases v 1.7 expected, 90% CI of relative risk (RR) 1.5 to 7.0). Five of the six cases had started to work at the refineries in the 1950s or later. No other significantly increased risk of cancer was found. Distribution workers had a decreased incidence of lung cancer (no cases, 90% CI of RR 0 to 0.4).Conclusions: Operators at Swedish refineries had an increased risk of leukaemia. A possible cause is exposure to benzene. There was no increased risk of leukaemia in distribution workers. Distribution workers had a decreased risk of lung cancer. [ABSTRACT FROM AUTHOR]

Benzene is an established cause of leukemia in adults, especially acute non-lymphocytic leukemia (ANLL). A few studies have indicated that exposure to gasoline is a cause of childhood leukemia. The purpose of this study was to investigate if environmental exposure to benzene from gasoline and car exhaust was associated with leukemia in children and young adults. The exposure to gasoline and car exhaust was estimated by the number of cars per area. In this ecology study, data on the incidence of cancer in each municipality of Sweden during an 11-year period (1975-1985) were compared with the number of cars per area. Data on the incidence of cancer for persons aged 0-24 years at diagnosis were collected from the National Swedish Cancer Register. The following diagnoses were studied: non-Hodgkin's lymphoma, acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML). We found an association between AML and car density. In municipalities with more than 20 cars/km2 the incidence of AML was 5.5 [95% confidence interval (CI) 4.4-6.8, n = 89] as compared with 3.4 (95% CI 1.9-5.7, n = 15) cases per 1 million person-years in municipalities with less than 5 cars/km2 (P = 0.05). No association was found for the other sites of cancer studied. The association between AML in young adults and car density might be attributable to exposure to benzene from gasoline vapors and exhaust gases, but further investigations are necessary before any definite conclusion can be drawn.