Radiation protection of the natural environment. Review

We witness expanding the scientific basis of radiation protection of the natural environment. International databases to collect radiobiological effects on the non-human biota studied in many laboratories around the world, including Russia, were developed. Unique results of long-term radiobiological effects on the biota in territories of Russia contaminated with radionuclides were added to the international database FREDERICA (www.frederica-online.org). Concept of threshold effect of ionizing radiation on the biota was scientifically proven. Criteria for radiation safety of the natural ecosystems were developed as a result of experimental data examination. Standard models for assessment of dose-rates to referent non-human species were developed. Research into modeling radioecological effects on the non-human biota is carried out. Methodology for assessment of economical loss due to exposure of the natural ecosystem to radiation was developed. Radiotoxicity of alpha-emitters was found to be higher as compared with gamma ray-emitters. The method for assessment of ecological risk was tested in wide range of specific areas, such as territories contaminated with radionuclides as a result of the Kyshtym and Chernobyl accidents, areas in which Russian NPPs, radiochemical plants, and uranium production facilities are located. Regulatory documents and guidelines of assessment of radioecological effects, estimation of reference concentration of radioactive substances according to ecological criteria and measurement of background were developed. Despite the advances in radiation protection, a lot of scientific questions, such as necessity to use alpha radiation quality factor for doses to non-human biota, development of more detailed "dose-effect" scale for natural species belonged to different groups by reference to specific features of their metabolism; simulation and experimental study of ecological processes for estimating economical loss and population recovery following exposure to radiation; research into biological effects of ecological stressors other than radiation, need to be studied.