Recent findings on the carcinogenicity of chlorinated olefins

Data are presented on factors affecting the carcinogenic effects of chlorinated olefins, such as molecular structure, concentration, length of treatment, route of administration and animal species, strain, sex, and age. The observations are based upon carcinogenicity experimental bioassays of vinyl chloride and vinylidene chloride. Early results, which appear to show that some of these factors (particularly species, strain, and sex) act by affecting the metabolism of the tested compounds, are presented, and the need for metabolic characterization of experimental animals in chemical carcinogenesis is stressed.