25 years after the accident at the Chernobyl nuclear power plant: Radioecological lessons

The area affected by the Chernobyl accident has become a unique test site where long-term ecological and biological consequences of a drastic change in a range of environmental factors as well as trends and intensity of selection are studied in natural settings. The consequences of the Chernobyl accident for biota varied from an enhanced rate of mutagenesis to damage at the ecosystem level. The severity of radiation effects was strongly dependent on the dose received in the early period after the accident. The most exposed phytocenoses and soil animals’ communities exhibited dose dependent alterations in the species composition and reduction in biological diversity. These findings make a valuable contribution to scientific and public understanding of the environmental risks of ionizing radiation and to debates on the environmental costs, benefits and risks of nuclear energy

Development of an approach to assess critical doses and dose rates for cultivated plants

The aim of this work is to develop methods for an assessment of critical doses and dose rates that can result in significant radiation-induced effects in agrocenoses. This is realized on an example of cultivated plants which are one of the main components of agroecosystems. Available information on dose dependences in such umbrella endpoints as reproduction, survival, morbidity, alterations in morphological and biochemical processes, genetic effects in crops, vegetables, fruit trees, etc are gathered from papers issued mainly in Russian scientific press during last 50 years. Data are maintained as database in MS Access that contains about 10000 records at the moment. As critical exposure values, doses are considered producing 50% changes of biological effect at acute impact (ED50), or dose rates resulting in 10% changes at chronic exposure of plants (EDR10). The critical doses and dose rates for agrocenosis estimated from available information on reproduction and survival are presented here. Primary data are assesed for their quality according to several criteria. Three models (linear, logariphmic, logistic) for dose-effect relationship are tested for an applicability to fit a dose-effect dependence taking account of their goodness-of-fit and robustness of ED50 and EDR10 estimates

Study of needle morphometric indices in Scots pine in the remote period after the Chernobyl accident

Biological effects in Scots pine populations experiencing chronic radiation exposure at doses up to 130 mGy per year as a result of the Chernobyl accident were studied in 2011 and 2013, using needle indices as endpoints. No relationships between the length, the mass of needles and the asymmetry in weight of paired needles and radiation exposure were revealed. The frequency of necrotic needles increases with the level of radiation exposure; however, the significance of these effects in different years was different. The index of fluctuating asymmetry in needle length significantly increases at annual doses of 90 and 130 mGy and correlates with the absorbed dose as well as 137Cs and 90Sr radionuclide activities in soils and cones at the study sites. The findings obtained are consistent with an international recommendation to consider radiation exposure of 100 mGy.y-1 as a margin for biota safety in chronic irradiation