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The aim of this study was to analyze the current radioecological situation in agriculture in five south-west districts of the Bryansk region, which were exposed to the most radiation influence due to the accident at the Chernobyl NPP. Currently, there are 135 collective farms in the observed areas. The total area of agricultural lands was 266.2 thousand hectares. The area of agricultural lands with 137Cs contamination over 37 kBq/m2 was 244.8 thousand hectares in 2018. The area of arable land, hay fields and pastures located in the zone with a 137Cs soil surface activity in a range of 37–185 kBq/m2 is 135.1 thousand hectares, 185–555 kBq/m2– 88.3 thousand hectares, 555-1480 kBq/m2 – 19.8 thousand hectares. At present, only 21.4 thousand hectares (8% of the agricultural lands in the considered areas) don’t exceed contamination levels of 137Cs 37 kBq/m2, and they can be classified as “clean territory”. Analysis of the agricultural products radiation monitoring data from the collective farms of the south-west districts of the Bryansk region showed that the part of feed and crop products exceeded the standards varied from 4 to 15% in 2017-2018. The high content of 137Сs in the feed of several collective farms determined the excess of sanitary and hygienic standards in livestock products from these farms – milk in 4-8% of total samples, beef in 5–8% of total samples. The collective farms located in Krasnogorsky and Novozybkovsky districts of the Bryansk region, with a high risk of exceeding the standards for the content of radionuclides in the agricultural products, was identified. The required volumes of rehabilitation measures in the plant growing and animal husbandry of the south-west districts of the Bryansk region was indicated. It was found that 75 thousand hectares of the total area of agricultural lands need radical improvement and the introduction of higher doses of agromeliorants to produce plant-growing and fodder products corresponding to the legislation standards. To produce milk and beef that comply with sanitary and hygienic standards for livestock products, it is necessary to use ferrocyanide treatment in volumes of 10.5 t/a. It was shown that most radioactively contaminated rural areas need individual programs for the application of rehabilitation technologies. Such programs should provide the population safety and domestic activity.

An extensive programme of experiments on transfer of radionuclides to aquatic species was conducted in the former USSR starting from the early 1950s. Only a few of these studies were made available in the English language literature or taken into account in international reviews of radionuclide behaviour in marine ecosystems. Therefore, an overview of original information on radionuclide transfer to marine biota species available from Russian language literature sources is presented here. The concentration ratio (CR) values for many radionuclides and for marine species such as: (239)Pu, (106)Ru and (95)Zr (crustacean), (54)Mn, (90)Sr, (95)Nb, (106)Ru, (137)Cs (239)Pu, (241)Am and natural U (molluscs), and (54)Mn, (90)Sr, (137)Cs and (144)Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for (32)P and (110)Ag (crustaceans), (35)S (molluscs), (32)P, (35)S, (95)Nb, and (106)Ru (macroalgae) and (60)Co and (239,240)Pu (fish) the data presented here suggest that changes in the default CR reference values presented in recent marine reviews may be required. The data presented here are intended to supplement substantially the CR values being collated within the handbook on Wildlife Transfer Coefficients, coordinated under the IAEA EMRAS II programme.

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