Bioaccumulation of radionuclides in hoofed animals inhabiting the Semipalatinsk Test Site.

Abstract

The article assesses the content of radionuclides in hoofed animals inhabiting the Semipalatinsk Test Site by calculation. Hoofed animals' faeces were sampled to determine the content of radionuclides in their diets. Based on values determined for the content of radionuclides in animals; diets, the content of radionuclides in the meat and milk of farm animals-cows (Bos taurus taurus), sheep (Ovis), goats (Capra hircus) and horses (Equus caballus Lin., 1758) as well as in the meat of wild animals-european moose (Alces alces Lin., 1758), argali (Ovis ammon Lin., 1758), roe deer (Capreolus pygargus Pal., 1771) and saiga (Saiga tatarica Lin., 1766) was calculated. No excess of permissible values of the content of 137Cs and 90Sr in the meat of farm animals was found to be expected, even for a conventional 'conservative' scenario, in which maxima of the radionuclide activity concentration in a vegetable feed (faeces) are taken as a basis. 241Am and 239+240Pu in the meat of farm hoofed animals are not standardized. Their predicted maxima of activity concentration are very low, and even in the 'conservative' scenario, they do not exceed 1.8×10-2 Bq kg-1, 1.4×10-1 Bq kg-1 and 1.6×10-1 Bq kg-1, respectively. In the milk of farm animals, the content of 137Cs and 90Sr does not exceed permissible values. 241Am and 239+240Pu in the milk of farm animals are not standardized. Their predicted activity concentration values in the milk of sheep and goats do not exceed 6.5×10-2 Bq l-1, for cows- 2.6×10-2 Bq l-1, for horses- 3.1×10-2 Bq l-1. Permissible values of 137Cs and 90Sr in the meat of wild hoofed animals are not exceeded either. In the meat of argali, roe deer and saigas, relatively high levels of 137Cs are predictable. 241Am and 239+240Pu in meat of wild animals are not standardized. Their predicted activity concentration values in the meat of moose and argali do not exceed 3.2×10-1 Bq kg-1 and 1.6×10-1 Bq kg-1, respectively, for roe deer and saiga-5.4×10-2 Bq kg-1. Thus, in case of free grazing in the STS territory, no excess of permissible values of standardized radionuclides (137Cs and 90Sr) in the meat and milk of hoofed animals is predictable.