Peculiarities in accummulation of radionuclides by fruit and berry trees and shrubs

The paper provides results of a long-term natural experiment with fruit and berry crops, grown in conditions of radioactive contamination at the territory of the former Semipalatinsk Test Site. The aim of the research is to study peculiarities in accumulation of artificial radionuclides by different species of trees and shrubs. The paper considers only one pathway of the radionuclide's intake, i.e. absorption of the elements by roots from soil. As the result quantitative parameters of ²⁴¹Am, ¹³⁷Cs, ⁹⁰Sr, ^239+240Pu transfer and distribution in different parts of the fruit and berry crops were found. At that radionuclides are not uniformly distributed in plants' organs and in most cases, it obeys the following regularity: leaves > branches > fruits. The difference in accumulation of ¹³⁷Cs, ⁹⁰Sr, ²⁴¹Am and ^239+240Pu for various organs can be range as follows 1.8-77, 1.6-750, 1.9-76 and 3-182 times respectively. The maximum concentrations of ¹³⁷Cs in leaves of the researched plants more often were registered at the initial stages of vegetation period. Unlike ¹³⁷Cs concentration of ²⁴¹Am and ⁹⁰Sr in leaves of the researched plants grows usually from the very beginning till the end of the entire vegetation period. The character of transuranium radionuclides accumulation during several years was determined for researched plants. Data obtained can become input parameters for models used to describe the behavior of radioactive substances and assess the risk of contaminated fruit and berry crops for territories having unfavorable radiological situation.