Радіоактивне забруднення конвалії звичайної (Convallaria Majalis L.) у лісах Житомирського Полісся

The results of studies of the dynamics of radioactive contamination of terrestrial phytomass of lily of the valley (Convallaria majalis L.) in the wet territories of Zhytomyr Polissya (1991‑2018) are presented. A decrease in the density of radioactive contamination of soil during the observation period was noted. Thus, for the sample plots–5 (minimum values) this indicator decreased in 2.5 times (from 111.0±6.32 kBq/m2 to 43.7±6.38 kBq/m2), and for the sample plots–2 (maximum value) in 2.6 times (1110.0±74.4 kBq/m2 to 419.8±33.63 kBq/m2). Higher values of the specific activity of 137Cs in inflorescences of the lily-of-the-valley with respect to the value of this indicator in its grass were observed at all the sample plots in 1.3‑2.5 times. A reduction of 137Cs in the grass lily of the valley for 27 years (1991‑2018) was found to decrease in 11.1‑17.3 times. This indicator was found to increase in certain years and periods, which may be related to the weather conditions of a particular year and the cyclical migration of 137Cs in forest biogeocenosis. The intensity of radionuclide inflow into the studied parts of the lily of the valley was slightly higher in 1998 compared to the results obtained in 2018, but the correlation between the two years of observations remains. The values of the radionuclide transition coefficient for both inflorescences (3.8‑8.2 m2 kg-1 10-3) and grass (1.9‑5.1 m2 kg-1 10-3) of lily of the valley are small, which allows classifying this plant as one with moderate storage of 137Cs. It has been found that, at present, only 1.3 % of the total 137Cs activity in the soil is contained in the forest litter, and its bulk has moved to the 10 cm top of the soil mineral layer, and is 90.06 %. As a result, a recent relationship was established between the density of radioactive 137Cs contamination of soil and the specific activity of radionuclide in grass and inflorescences of lily of the valley.