Objective: There is some evidence to suggest that workers in animal-related occupations are at increased risk of developing lymphohematopoietic cancers. This study aimed to examine the risk of leukemia, non-Hodgkin's lymphoma (NHL), and multiple myeloma associated with occupational exposure to animals.
Methods: We used data from a multi-site, population-based case-control study using mailed questionnaires which had taken place in eight of ten Canadian provinces, during 1994-1998. There were 1023 leukemia cases, 1577 NHL cases, and 324 multiple myeloma cases (all histologically confirmed) and 4688 population-based controls. Animal-related occupations were identified from a lifetime occupational history. Subjects in animal-related jobs were compared with others using logistic regression for the risk of leukemia, NHL, and multiple myeloma.
Results: Compared to subjects without occupational exposure to animals, occupational exposure to beef cattle increased the risks of leukemia (odds ratio (OR) 2.0, 95% confidence interval (CI) 1.2-3.3) and NHL (OR 1.8, 95% CI 1.1-2.9). No other animal exposure was consistently associated with risk of lymphohematopoietic cancer. An unexpected protective association was observed between work as a fisherman and leukemia (OR 0.4, 95% CI 0.2-0.8) and NHL (OR 0.6, 95% CI 0.4-0.9).
Conclusions: This population-based case-control study found that those individuals working in occupations associated with beef cattle are at increased risk for developing leukemia and lymphoma while those working in occupations requiring the handling of fish are at decreased risk of leukemia and lymphoma.