The effect of industrial and agricultural contamination of the environ
ment on the formation of micronuclei in peripheral blood cells of the
lake frog Rana ridibunda P. was studied. Simultaneously, the influence
of mutagenic contaminants on the human gene pool in Astrakhan' and As
trakhan' oblast' was analyzed. Frogs were trapped in three raions of A
strakhan' oblast': the villages of Trudfront and Verkhnii Buzan and Ob
livnoi Island. Peripheral blood smears were prepared and cells with mi
cronuclei and nuclear material were analyzed. Cells with micronuclei w
ere 94.5 times more abundant in frogs from ecologically unfavorable Ob
livnoi Island than in animals from Trudfront and 1.2 times more plenti
ful than in frogs from Verkhnii Buzan.