Artificial radionuclides in fish fauna of the Yenisei River in the vicinity of the Mining-and-Chemical Combine (Siberia, Russia)

Abstract

Activities of radionuclides were measured in five species of fish (grayling, dace, crucian carp, pike, cod) sampled in the Yenisei River (Siberia, Russia) in the vicinity of the Mining-and-Chemical Combine (ROSATOM) from 2007 to 2010, with a gamma-spectrometer (Canberra, USA). The analyses of samples of organs and tissues of fish species revealed artificial (46 Sc, 51 Cr, 54 Mn, 58,60 Co, 59 Fe, 65 Zn, 85 Sr, 99 Mo, 103,106 Ru, 137 Cs, 141,144 Ce) and natural (7 Be, 40 K) radionuclides in fish organs and tissues, including edible ones. The major percent (up to 80%) of 137 Cs and 40 K activity occurred in muscles of fish species, which also contained considerable percentages of 60 Co (up to 70%) and 65 Zn (up to 20%). Seasonal changes in the intake of artificial radionuclides by zoobenthos-feeding fish species (grayling and dace) were recorded and they were followed by an activity concentration increase in internal organs. The dramatic increase in radionuclide intake by grayling coincided with the change of diet source. Hence, the feeding behavior of fish can change the fluxes of artificial radionuclides in the Yenisei River. The most effective diet transfer of a radionuclide from gammarus to grayling (muscles and total body) was recorded for 40 K (1.3) and much less effective for artificial nuclides.