Review and meta-analysis of studies of acrylonitrile workers.

Twenty-five epidemiologic studies of acrylonitrile workers were reviewed and subjected to meta-analytic techniques in this study to assess the findings for 10 cancer sites. The analyses indicate that workers with acrylonitrile exposure have essentially null findings for most cancers, including lung [meta-relative risk (mRR) 0.9, 95% confidence interval (95% CI) 0.9-1.1], brain (mRR 1.2, 95% CI 0.8-1.7), and prostate (mRR 1.0, 95% CI 0.7-1.4) cancers. Bladder cancer rates were elevated (mRR 1.8, 95% CI 1.0-3.4), but the excess was not dose-related and was limited to plants with aromatic amines. Therefore, the bladder cancer excess is unlikely to be related to acrylonitrile exposure. Some evidence of publication bias was found in the examined literature, but the bias did not have a significant impact on risk estimates for individual cancers. It was concluded that the available studies do not support a causal relation between acrylonitrile exposure and cancer.