Radioactive residue burdens in soil, foodstuffs, animal feed and biological material

Abstract

Peaceful uses of nuclear energy (nuclear weapons testing, nuclear reactor accidents, industrial and medical use of radioactive compounds) and application of phosphate mineral fertilizers in agricultural production lead to substantial environmental contamination. Land contaminated with radionuclides represents the first link in the food chain and hence the radioactive contamination of crop and livestock production. Activity concentrations of radionuclides gamma emitters were determined by the method of low-level gamma spectrometry on high resolution HPGe detector system produced by ORTEC. Concentrations of thorium and uranium in all samples were analysed by a technique of inductively coupled plasma with mass spectrometry (ICP-MS 7700, Agilent). The samples of the soil, foodstuff (meat and meat products, milk and dairy products, fish, honey), animal feed (complete mix, concentrated pre-mix feed, phosphate mineral feed, fish meal) and biomaterials (internal organs, urine) were examined. The results revealed the presence of the following natural radionuclides: K-40, Ra-226, Th-232, U-235 and U-238. Besides, the presence of Cs-137, that is, an anthropogenic (artificially produced) radionuclide has been confirmed. Based on the results obtained, it can be concluded that in all tested samples the highest concentration of activity originates from natural radionuclide of potassium-40. Also, in this study, the content of the tested radionuclides in different environmental samples gives interesting additional data for an approximate calculation of the average input of radioactive residues.