Testicular cancer, occupation and exposure to chemical agents among Finnish men in 1971-1995.

OBJECTIVE: To find associations between testicular cancer, occupation and chemical exposure. METHODS: A cohort of all economically active Finnish men born between 1906 and 1945 was followed-up for 19.7 million person-years during 1971-1995. Incident cases of testicular cancer (n=387) were identified in a record linkage with the Finnish Cancer Registry. The Census occupations in 1970 were converted to chemical exposures with a job-exposure matrix (FINJEM). Cumulative exposure (CE) was calculated as the product of prevalence, level, and duration of the exposure. Standardised incidence ratio (SIR) was calculated for each of the 393 occupations, and for CE categories of the 43 chemical agents, using average male population as reference. Relative risks (RR) comparing various CE-categories with unexposed ones were defined for selected agents by Poisson regression analysis. RESULTS: Elevated SIRs were observed among railway traffic supervisors (5.8, 95% CI 1.6-14.7), programmers (4.3, 1.4-9.9), university teachers (4.1, 1.3-9.5) and electrical engineers (3.9, 1.1-10.1). A significant exposure-response trend (mainly contributed by seminoma) was observed for pesticides, textile dust, aliphatic and alicyclic hydrocarbons, and some other organic solvents. CONCLUSIONS: Risk of testicular cancer increased only in four occupations. Pesticides, textile dust, and some organic solvents may be related to an excess risk of seminoma.

National job-exposure matrix in analyses of census-based estimates of occupational cancer risk.

OBJECTIVES: The aim of this study was to increase the understanding of the alternative exposure metrics and analysis methods in studies applying job-exposure matrices in analyses of health outcomes, the association between crystalline silica and cancer being used as an example. METHODS: Observed and expected numbers of cancer cases during 1971-1995 among Finns born in 1906-1945 were calculated for 393 occupational categories, as defined in the 1970 population census. According to the Finnish Cancer Registry, there were 43 433 lung and 21 444 prostate cancer cases. The Finnish job-exposure matrix (FINJEM) provided estimates of the proportion of exposed persons and the mean level of exposure among the exposed in each occupation. RESULTS: The most comprehensive exposure metric included period- and age-specific estimates of exposure and an estimate of occupational stability, but also remarkably simpler metrics gave significantly elevated estimates of the risk ratio (RR) between 1.36 and 1.50 for lung cancer for occupations with the highest estimated cumulative silica exposure (> or = 10 mg/m3-years), allowing a lag time of 20 years. It proved important to adjust the risk ratios at least for the socioeconomic status and occupational exposure to asbestos. The risk ratios for prostate cancer were close to 1.0 in every model. CONCLUSIONS: The results showed that the FINJEM-based analysis was able to replicate the well-known association between exposure to crystalline silica and lung cancer. The FINJEM-based method gives valid results, and it can be used to analyze large sets of register-based data on health outcomes.

Risk of esophageal, ovarian, testicular, kidney and bladder cancers and leukemia among finnish workers exposed to diesel or gasoline engine exhaust.

Occupational exposure to diesel exhaust has been classified as probably carcinogenic and that to gasoline engine exhaust as possibly carcinogenic to humans. Earlier results concerning cancers other than lung cancer are scarce and inconsistent, and exposure-response relations have seldom been reported. We followed up a cohort of all economically active Finns born between 1906 and 1945 for 30 million person-years during 1971-1995. Incident cases of esophageal cancer (n = 2,198), ovarian cancer (5,082), testicular cancer (387), kidney cancer (7,366), bladder cancer (8,110) and leukemia (4,562) were identified through a record linkage with the Finnish Cancer Registry. Occupations from the population census in 1970 were converted to exposures to diesel and gasoline engine exhausts with a job-exposure matrix (FINJEM). Cumulative exposure (CE) was calculated as product of prevalence, level and estimated duration of exposure. The relative risk (RR) of cancer for exposure categories in relation to the unexposed group was calculated using the Poisson regression model and adjusted for confounders. An increasing RR for ovarian cancer was observed with the increasing CE of diesel exhaust (p for trend = 0.006). The RR in the highest CE category was 3.69 (95% CI = 1.38-9.86). For gasoline engine exhaust, the RR was significantly increased only in the middle CE category (1.70; 95% CI = 1.11-2.62). Slight elevations of RR for bladder and kidney cancers were found at the lowest exposure level of engine exhausts, largely attributable to drivers. No effect of the exposures was observed for the other cancers. This study suggests an exposure-response relation between diesel exhaust and ovarian cancer.

Occupational exposure to diesel and gasoline engine exhausts and risk of lung cancer among Finnish workers.

BACKGROUND: Studies on engine exhausts and lung cancer have given inconsistent results. METHODS: Economically active Finns were followed-up for lung cancer during 1971-95 (33,664 cases). Their Census occupations in 1970 were converted to exposures to diesel and gasoline engine exhausts with a job-exposure matrix. The relative risks (RRs) for cumulative exposure (CE) were defined by Poisson regression, adjusted for smoking, asbestos, and quartz dust exposure, and socioeconomic status. RESULTS: RR for engine exhausts among men did not increase with increasing CE. In women, RR for gasoline engine exhaust was 1.58 (95% CI 1.10-2.26) in the CE-category of 1-99 mg/m(3)-y and 1.66 (1.11-2.50) among those with > or =100 mg/m(3)-y (lag 20 years). With a lag of 10 years RR for the middle/highest diesel exhaust category in women was 1.42 (0.94-2.13). CONCLUSIONS: Occupational exposure to engine exhausts was not consistently associated with lung cancer in this study, possibly due to low exposure levels.