[Radionuclides in siberian Thymallus from radiation-contaminated area in the middle stream of the Yenisei River].

ABSTRACT

Concentration of artificial radionuclides in bodies of arctic grayling from the radioactively contaminated zone of the Yenisei River in the vicinity of the Mining-and-Chemical Combine of Rosatom was investigated in 2007-2010. Gamma-spectrometric analysis revealed artificial radionuclides in all the organs and tissues of fish. The isotope composition was the most diverse (60Co, 65Zn, 85Sr, 99Mo, 106Ru, 137Cs, 144Ce) in internal organs of grayling. The activity of radionuclides increased in internal organs including liver and kidney and in the content of digestive tract of grayling during winter and spring, which coincided with the change in the feeding spectrum of grayling. The trophic transfer factor of radionuclides from zoobenthos (Philolimnogammarus spp.) to whole bodies and muscles of grayling was over 1 (1.8-2.4) only for natural radionuclide 40K. The trophic transfer of artificial radionuclides (60Co, 65Zn, 137Cs) to muscles and bodies of grayling was one-two orders of magnitude less effective.