Cancer among pesticide manufacturers and applicators.

There are hundreds of studies of cancer and agriculture chemicals. However, few have focused on a single pesticide or class of pesticide. While cancer studies of nonspecific pesticide exposure among populations may provide hypotheses for additional testing, they contribute little to the understanding of the health risks of specific agricultural chemicals. This review concentrates on both the cancer findings and the exposure parameters in cohort studies of workers who manufacture or apply pesticides. Occupational studies of pesticide manufacturers and applicators provide important contributions to the causal assessment of the carcinogenicity of specific pesticides because the exposure is often longer, more intense, and better defined than for other study populations. Among the studies reviewed, there is little indication of increased cancer risk among pesticide manufacturers or sprayers. Limitations in sample size, exposure assessment, and the small number of studies make causal inference difficult. Additional methodological improvements with respect to exposure would contribute significantly to the understanding of the potential cancer risk from individual pesticides.