Natural and anthropogenic radioactivity in the environment of Kopaonik mountain, Serbia

To evaluate the state of the environment in Kopaonik, a mountain in Serbia, the activity concentrations of (4) K, Ra-226, Th-232 and Cs-137 in five different types of environmental samples are determined by gamma ray spectrometry, and radiological hazard due to terrestrial radionuclides is calculated. The mean activity concentrations of natural radionuclides in the soil are higher than the global average. However, with an exception of two sampling locations, the external radiation hazard index is below one, implying an insignificant radiation hazard. Apart from K-40, content of the natural radionuclides is predominantly below minimum detectable activities in grass and cow milk, but not in mosses. Although Cs-137 is present in the soil, grass, mosses and herbal plants, its specific activity in cow milk is below minimum detectable activity. Amongst the investigated herbal plants, Vaccinium myrtillus L. shows accumulating properties, as a high content of Cs-137 is detected therein. Therefore, moderation is advised in consuming Vaccinium myrtillus L. tea.