Considerations for evaluating chemical mutagenicity to germinal cells.

Modern technology has created a vast pool of chemical pollutants that invade man's environment daily. The mutagenic, teratogenic, and carcinogenic potentials of the majority of these chemicals have not yet been evaluated. It is vital to screen as many of these substances as is feasible for their genetic risks, with the ultimate goal of eliminating the potentially hazardous compounds from the environment, thereby reducing genetic damage in man. In evaluating the genetic hazards of a chemical to man, consideration must be given to mutations caused to both somatic and germinal cells. In the case of mutations to somatic cells, the primary concern is about the potential of carcinogenesis-a concern to the immediate individual. For mutations to germinal cells, the risks are to the future population. No test system today is adequate to truly assess the risk to all types of somatic and germinal cells. To evaluate mutagenic effects on germinal cells, three mammalian test systems are generally available. These are the dominantlethal test (1-4), the specific-locus test (4, 5), and the translocation test (6, 7). Of these systems, the dominant lethal test has been more widely accepted and evaluated, partly because it is less expensive and simpler to perform. In the dominant-lethal test, rodents are treated with the chemical agent and then