Cancer mortality in U.S. counties with plastics and related industries.

Counties in the United States have been identified with chemical establishments whose primary manufacturing processes use vinyl chloride. Site-specific cancer mortality comparisons have revealed an excess of multiple myeloma in males associated with two of the manufacturing categories, synthetic rubber and synthetic fibers. A causal relationship between these manufacturing categories and multiple myeloma could not be established. An industry-based assessment of the occupational contribution to this excess is needed to evaluate the etiologic importance of this relationship.