The investigation of radionuclide concentrations in soil and lifetime cancer risk due to gamma radioactivity in Zonguldak, Turkey

Abstract

The distributions of Ra-226, Th-232, K-40 and Cs-137 activity concentrations were determined using a high-purity germanium detector in uncultivated surface soil samples collected from Zonguldak. The range of Ra-226, Th-232, K-40 and 137Cs activity concentrations varied from 10.5 +/- 2.0 to 98.0 +/- 4.3 Bq kg(-1) (mean value 28.8 +/- 4 Bq kg(-1)), from 12.9 +/- 3.4 to 53.2 +/- 5.1 Bq kg(-1) (mean value 29.6 +/- 3 Bq kg(-1)), from 190 +/- 22 to 808 +/- 43 Bq kg(-1) (mean value 395 +/- 31 Bq kg(-1)) and from < 0.5 to 47.1 +/- kg(-1) (mean value 12.5 +/- 2 Bq kg(-1)), respectively. In addition, the mean outdoor absorbed dose rates in air (terrestrial, terrestrial+cosmic), annual effective dose equivalent, radium equivalent activity and external hazard index were found to be 48 nGy h(-1) (terrestrial), 56 nGy h(-1) (terrestrial+cosmic), 58 mu Sv y(-1), 101 Bq kg(-1) and 0.27, respectively. The evaluated excess lifetime cancer risks (ELCRs) varied from 0.13 x 10(-3) to 0.36 x 10(-3) with a mean value of 0.20 x 10(-3).