Genetic Effects of Combined Action of Some Chemicals and Ionizing Radiation in Animals and Human Cells

Abstract

Environmental contamination by radionuclides and different chemi- cal substances results in exposure of human and other beings to a complex of physical and chemical factors. Results of combined influence of diverse agents can be unpredictable, because observed effects can differ from the sum of effects of each one taken separately.We studied cytogenetic effects of sodium nitrite and nitrate in drosophila and mice. It was found that these substances didn't possess mutagenic activity and sensibilized significantly (2-4 times) genetic effect of ionizing radiation. Genetic effects of herbicide zenkor were found to be completely different. Zenkor has mutagenic activity and irradiation of zenkor-treated mice results in decreasing aberration levels. Chronic influence of zenkor and gamma-rays leads to more strict antago- nistic effect than acute one. Such effect can be explained by increased death of cells treated with both mutagenic factors - zenkor and irradiation. In the same time many food stuffs contain radioprotectors or antimutagens. We shown that melanin is very effective radioprotector not only against acute irradiation, but even against chronic one. Influence of different substances (melanin, tocopherol or zenkor) on fractionated irradiation is also different. So, phenomena of sensibilization, antagonism, protection or inhibition were observed. Influence of combined action of chemical and physical factors on hereditary structures are worthy of great attention and must be considered during taking environmental protection measures.