It is impossible to protect human heredity from the ecological consequences of environmental pollution if there is no permanent control of hereditary variability in human populations, i.e. genetic monitoring. One of the urgent problems in genetic monitoring planning is the magnitude of representative samples necessary for establishing the significant mutation effect of environmental factors. The elevation of the mutation frequency can be determined either by the dynamics of the frequencies of hereditary pathology or by comparison of the frequencies in populations that differ in harmful factor exposures. Comparison of the effects evaluated by cytogenetic, epidemiological (registration of congenital malformation frequencies) and molecular-genetic methods in various population groups will make it possible to solve the problem of safety in the investigated regions.