Concentrations of Ra-226, Th-232 and K-40 in industrial kaolinized granite

摘要

Activity concentrations of Ra-226, Th-232 and K-40 in 120 kaolinized granite samples imported in Serbia from the Motajica mine, Bosnia and Herzegovina, were measured. The Ra-226 concentration ranged from 61 to 319 Bq kg(-1), the Th-232 from 44 to 272 Bq kg(-1), and the K-40 from 590 to 1470 Bq kg(-1). The frequency distribution of K-40 concentrations was near-Gaussian, where those of Ra-226 and Th-232 were right-skewed. In 6 samples, the gamma index, I, was higher than 2, which exceeds the exemption dose criterion (03 mSv y(-1)). The absorbed dose rate and annual effective doses for workers in the ceramic industries in Serbia who worked with kaolinized granite were below levels of concern. (C) 2016 Elsevier Ltd. All rights reserved.