Multiple myeloma and occupation in Sweden.

The occurrence of multiple myeloma by occupational and industrial category was systematically assessed using the Swedish Cancer-Environment Registry, which links cancer incidence (1961-1979) with occupational data from the 1960 census. Incidence of multiple myeloma was significantly increased for a number of occupational groups such as farmers, smelter and metallurgy workers, and miners-quarrymen-rock blasters. Although caution must be applied in drawing causal inferences, this national linked-registry analysis may provide clues to the environmental determinants of multiple myeloma.