Chemical toxicants and electrical abnormalities created by ionizing radiation in the environment - impact on biota

The paper presents impact of indirect effects of ionizing radiation (IR) on biota. Along with direct harmful effects on non-human biota IR induces indirect effects on biological species via toxic radiolytic products and reactive species in soils and highly ionized ground air. Impacts of ionization-generated chemicals hazardous to soil bacteria and invertebrates, observed in the areas affected by the Kyshtym and Chernobyl accidents are considered in the paper. The magnitude of observed response of the species inhabited in radioactively contaminated soils does not correlate with their response to absorbed radiation dose. The observed sensitivity of these organisms differs from their sensitivity to acute radiation exposure. Methods for calculating the generation of radiolytic products and air ions in the habitat of the organisms are described in the paper. Estimates of generation of radiolytic and air ionization-induced toxic substances in the contaminated areas are given in the paper, as well. The higher radiolytic production rate was in areas contaminated with alpha- or beta-emitters. Examples of observed radiation-induced effects on inferior living organisms - soil bacteria and invertebrates that do not correlate with the radiation doses are considered in the paper. From the analysis of computed estimates and apparent radiation-induced effects on the biological species permanently living in radioactively contaminated environment, it is possible to hypothesize that indirect radiation-induced effects transferred to biological species via toxic radiolytic chemicals in soils and in the ground air make significant contribution to the total harmful effect of IR on biological species sensitive to highly reactive radiolysis products. Including secondary effects in the general picture of ionizing radiation effects on health status of biological species living in the environments affected by radiation will improve our knowledge and understanding of variety of radiation impacts on non-human living species. To improve the knowledge of indirect radiation effects on the environment and to advance environmental radiation protection laboratory and field research should be continued.