Morphometric Measurements of Scots Pine Needles from Radioactively Contaminated Area

The morphometric indices of needles were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as a result of the Chernobyl Nuclear Power Plant accident. The variability in needle weight and length, as well as the fluctuating asymmetry indices were studied in seven contaminated and two reference populations of Scots pine in 2011, 2013, 2014 and 2016. The weight of needles in the contaminated populations was significantly higher than in the reference population; however, the dependence of this index on the level of radiation exposure was not revealed in the studied range of doses. The length of needles differed significantly from the references populations. The effect changed from decreasing to increasing in various years of observation; however, in 2016 this index decreased with the dose rate of β-radiation. The index of fluctuating asymmetry in needle length was significantly higher than at the reference sites during three years and correlated to the estimated annual absorbed dose in 2011 and 2013. No relationship was revealed between the asymmetry in weight of paired needles and radiation exposure

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