Risk assessment of human exposure to radionuclides in soli of urban areas (public parks and open playgrounds) in Kruševac, Serbia

Abstract

This study aims to ob tain data on ter res trial ra dio ac tiv ity com ing from nat u rally oc cur ring (40K, 226Ra, 232Th, and 238U) and artificial (137Cs) radionuclides in sur face soil (0-10 cm) of se lected eigh teen pub lic-ac cess ur ban ar eas in Kruševac city, Ser bia, and to as sess the cor re - spond ing health ef fects for cit i zens us ing those ar eas for rec re ational pur poses. The spe cific activities of investigated radionuclides were analyzed using HPGe gamma-ray spectrometry. The mean spe cific ac tiv ity of 40K, 226Ra, 232Th, 238U, and 137Cs was found to be 353, 39.8, 38.9, 41.0, and 5.9, re spec tively, in com pli ance with their val ues in other parts of Ser bia and neigh bor ing coun tries re ported in sim i lar re searches. To eval u ate the hu man health risk as so - ciated with radionuclides, con serva tive exposure assump tions and models recommended by the United States En vi ron men tal Pro tec tion Agency were em ployed tak ing into ac count three exposure routes: ingestion, inhalation of soil, and exter nal irradiation. The absorbed gamma dose rate in the air due to nat u ral radionuclides in soil was cal cu lated. The cal cu lated indices suggested that the radiation risk arising from natu ral and artificial radionuclides was not sig nif i cant. The to tal ex cess life time can cer based on the 95 % up per con fi dence limit of the spe cific ac tiv i ties mean was cal cu lated to be 5.89×10–6, lower than the tol er a ble risk for regulatory purposes (10–4). Among investigated radia tion exposure pathways, exter nal expo - sure was the most con trib ut ing one for the health risk. The re sults ob tained for the city's parks and play grounds sug gested their safe use for rec re ational pur poses from the radioecological point of view.