[Carcinogenic hazard of chloroform and other drinking water chlorination by-products]. 
The paper presents the results of studying the carcinogenic effect of chloroform and its combination with carbon tetrachloride, 1,2-dichloroethane, trichloroethylene during chronic oral administration to F1(CBAxC57Bl6) mice.  There is a relationship between the manifestation of carcinogenesis to the dose of chloroform and a combination of chemicals, as well as its enhancement upon exposure to the combination as compared with acute administration of chloroform.  Exposure to a combination of substances at the level of their maximum permissible concentrations does not affect carcinogenesis.  The possible mechanisms of the specific features of carcinogenesis in this experiment are discussed.