Aim: The purpose of the article was to provide a radioecologically proven method for normalization of cesium-137 content in the soils of Ukraine contaminated in the Chernobyl nuclear power plant accident..
Introduction: Years of experience in the liquidation of consequences of the large-scale nuclear accidents that have occurred on the Earth let us know that the primary condition for carrying out operations aimed at fighting consequences of such situations and ensuring radiation safety of the population is accurate and quick prediction of the levels of the radioactive contamination of foodstuffs, which constitute the main radiation dose to the population. Such prediction is possible only after determining permitted levels of soil contamination which would guarantee that the hygienic standards of agricultural products and processed products are preserved.
Methodology: The study was conducted on the main types of soils from contaminated areas of Ukraine (sodic-podzolic, peat-gley, black soil). The authors applied classical agrochemical and radioecological methods used in the field studies. The authors used analytical research methods of radioecological situation in agricultural production on radioactively contaminated regions, gamma-spectrometric methods for the analysis of selected samples and the methods of mathematical statistics using the application package Microsoft Excel.
Results: The analysis of factors that affect the application of the method for determining numerical indicators of cesium-137 content in the soils of farmland Ukraine showed that the norm of acceptable content of cesium-137 in soils of agricultural land for the long term, is possible only after the relative stability of the parameters of the migration of radionuclides from soil to plants. Such stabilisation is possible in 15-20 years after the accident. There was a 40 fold difference between the values of the cesium-137 coefficients of proportionality depending on the type of soil. Location of the test sites did not effect in the raise of the coefficient more than by 200%. The accumulation of cesium-137 in the yield of crops grown on peat-gley soils was 3,5-40 times higher (the values of TF-coefficient of proportionality) than in cultures grown on ashed, and 1,4-13 times higher than in cultures grown on sodіс - podzolic soils.
Conclusions: The basic method of determining permissible ratio of cesium-137 content in soil in the remote period after the Chernobyl accident is the quantitative parameters of the transfer of radionuclides from soil to different types of major crops (TF), and the conventional methods of the forecasting of radionuclides from soil to plant and animal agricultural input in which the content of cesium-137 will not exceed state sanitary standards (permissible level-2006, PL-2006) for foods produced from this raw.
Keywords: the Chernobyl accident, agriculture, soils, radioactivity, contamination, cesium-137, migration, parameters, radiological normalization
Type of article: original scientific article