Exposure to formaldehyde and cancer mortality in a cohort of workers producing resins.

The mortality of 1,332 male workers employed at least 30 days in 1959-1980 in a resins-manufacturing plant was examined. Ambient measurements taken in the plant between 1974 and 1979 documented a potential for exposure to levels of formaldehyde as high as greater than 3.0 mg/m3. Vital status was ascertained for 98.6% of the cohort members, and their mortality was compared with expected deaths drawn from the national and local population rates. A statistically significant increase in lung cancer was observed, based on 18 deaths, which was not fully accounted for by possible confounding factors linked to personal habits or sociocultural characteristics. This elevated risk, however, could not be attributed specifically to exposure to formaldehyde. Mortality from digestive cancer (14 deaths observed) and hematologic neoplasms (5 deaths observed) was not substantially higher than expected. The study was limited by information bias due to incomplete work histories, by the small number of deaths from some relevant causes, and by the possibly insufficient length of the observation period. Therefore these results do not provide sufficient grounds either to link formaldehyde exposure in the plant to the increased cancer risk noted or to exclude that formaldehyde might pose such a risk to humans under certain exposure circumstances.

[A follow-up study of 304 cases of suspected pathology caused by benzene seen in 1950-71]. / Studio a distanza di 304 casi di sospetta patologia da benzene osservati negli anni 1950-1971.

A group of 304 subjects admitted to the Institutes of Occupational Health of Milan and Pavia (Italy) between 1951 and 1970 for suspected benzene intoxication were retrieved from hospital records and their mortality experience was examined up to 31 December, 1986. The aims of the study were: 1) to estimate, in quantitative terms, the risk associated with benzene exposure in that area in the time period considered (these risks had already been reported, but merely as case reports); 2) to investigate the possibility of an increased frequency of neoplasms other than leukaemia; and 3) to further investigate the exposure history of these subjects. In the absence of data on the population at risk, mortality was analysed via the mortality odds ratio (MOR) method. A local population mortality experience was used as reference. Twenty-eight malignant neoplasms were observed (MOR = 2.2; 95% confidence interval = 1.3-3.7), 15 of which were haematologic neoplasms (MOR = 13.3; 95% confidence interval = 8.0-22.2). No odds ratio increases were observed for any of the other tumour sites or types. Eleven observed blood diseases represented a large numerical increase in the odds ratio. For all the haematologic neoplasms there had been an estimated exposure to airborne benzene concentrations above 20 ppm. However, no conclusions on dose-response relationships can be drawn from these data because of the approximate evaluation of individual exposure and, especially, because the study group most probably consisted of a highly selected sample of the exposed population.(ABSTRACT TRUNCATED AT 250 WORDS)