Excess lung cancer among workers exposed to lead

Abstract

lung cancer among workers exposed to lead. Scand J Work Environ Health 1995;21:460-9. Objective Studies on experimental animals suggest that inorganic lead is a carcinogen. The purpose of the study was to examine whether occupational exposure to lead increases the risk of cancer. Methods The study population comprised 20 700 workers who had been biologically monitored for their blood lead (B-Pb) concentrations during 1973-1983. The mortality and cancer incidence rates were followed among the monitored workers and compared with those of the Finnish general population. An internal comparison of the cancer incidence rates was also done between subcohorts formed according to individual B-Pb levels. Questionnaire-based information was also collected on lifetime occupational history and potential confounders, and exposure history was assessed on an individual basis with a nested case-referent design for lung cancer. Results The internal comparison within the cohort showed a 1.4-fold increase in the overall cancer incidence and a 1.8-fold increase in the incidence of lung cancer among those who had ever had a blood lead level of 2 1.0 ~m o l . 1-I. In the case-referent study, an increased odds ratio for lung cancer was found for concomitant exposure to lead and engine exhaust. The odds ratio for squamous-cell carcinoma of the lung was increased even when the blood lead level had been slightly elevated. Bias or confounding did not explain the risks. C O~C~U S~O~S The results suggest that exposure to lead increases the risk of lung cancer. Co-exposure to engine exhaust and lead may be associated with the risk.

Epidemiologic estimate of the proportion of fatalities related to occupational factors in Finland

“…Therefore, we calculated an alternative attributable fraction estimate. In the Finnish male population the proportion of men occupationally exposed to diesel engine exhaust in around 1970 was 46 attributable fraction for multiple risk factors in terms of the component attributable fractions by making a strong assumption of statistical and biological independence between the factors as follows (20): AF = 1 -(1 -AF a ) × (1 -AF b ) ... , (equation 5) where AF a is related to exposure a, and so forth. As an example, occupational exposures to metal dust and wood dust were considered biologically independent risk factors for cryptogenic fibrosing alveolitis (26) (ie, both factors predict the disease occurrence, but the factors do not modify each other's effects).…”

“…Hexavalent chromium and nickel welders [stainless steel welding (78)] were excluded from the estimate of the size of the chromium-and nickel-exposed populations in Finland. Excluded exposures included, among others, polycyclic aromatic hydrocarbons, man-made mineral fibers, metal dust (replaced by specific studies on exposure to arsenic, cadmium, lead, and nickel), leaded engine exhaust (46), solvent exposure of painters, and fertilizer exposure of chemical process workers. Some of the occupations, such as welder, sheet-metal worker, and transportation worker, can directly be connected with the exposure that the work involves (welding fumes, metal dust, and engine exhaust).…”

“…Our selection of the attributable fraction estimates for lung cancer relied on the results from occupational cohort studies conducted in Finland (43)(44)(45)(46)(47) and Sweden (29,48) and also on results from population-based case-referent studies carried out in Finland (49), Norway (50), Germany (24,(51)(52)(53)(54)(55), and Belgium (56).…”

“…Our overall attributable fraction estimate became 14% for men and 1% for women. Other included occupational exposures were lead (46), hydrocarbon solvents (14), and polycyclic aromatic hydrocarbons (73,123).…”

Brain cancer mortality and potential occupational exposure to lead: Findings from the National Longitudinal Mortality Study, 1979–1989

“…Nonetheless, several studies evaluating brain tumor subtypes or relying on (semi-) quantitative measures of exposure reported findings indicative of an association. [29][30][31][32][33][34] We assessed whether employment in occupations potentially involving exposure to lead compounds is related to an increased risk of mortality from brain cancer in the National Longitudinal Mortality Study (NLMS). The NLMS is a prospective censusbased cohort study of mortality among the noninstitutionalized United States population, conducted by the National Heart, Lung, and Blood Institute in collaboration with the National Center for Health Statistics and the United States Bureau of the Census.…”