a Faculty of Engineering, University of Kyrenia , Girne , Turkey.
b Faculty of Engineering, Near East University , Nicosia , Turkey.
Int J Radiat Biol. 2019 Feb;95(2):179-185. doi: 10.1080/09553002.2019.1539881. Epub 2019 Jan 8.
The purpose of this paper is to evaluate the morbidity excess cancer risk (ECR) due to internal and external exposure to three category levels of natural radionuclides in soil like U, Th and K. Although the exposure rate in soil is low but effect this radiation over time can lead to cancer risk and this risk can be calculated.
Natural activity concentration levels of K, U and Th in soil were selected from last reports in three concentration categories including: low, medium and high levels. The excess cancer risks of three concentration levels were calculated by means of RESidual-RADioactivity (RESRAD) code.
The calculated average morbidity ECR from K, U and Th in three concentration categories levels in soil were 1.40 × 10, 8.56 × 10 and 1.35 × 10, respectively. This calculation shows that the excess cancer risk value is the highest value in 100 years' time in all categories. Overall ECR from K radionuclide was maximal and the highest exposure pathways was through plant pathway; however, these pathway changes over 60 years to the drinking water pathway. The results of this study may be useful to risk assessment and for decision making for public health protection against high-level radiation.
本文旨在评估土壤中铀（U）、钍（Th）和钾（K）等三种天然放射性核素水平的内、外照射所致发病率超额癌症风险（ECR）。尽管土壤中的辐射暴露率较低，但这种辐射随时间的累积可能会导致癌症风险，而这种风险是可以计算的。
从最近的报告中选择土壤中 K、U 和 Th 的天然活度浓度水平，分为低、中、高三类。利用 RESidual-RADioactivity（RESRAD）代码计算三个浓度水平的超额癌症风险。
计算得出，土壤中 K、U 和 Th 在三个浓度类别水平的平均发病率 ECR 分别为 1.40×10、8.56×10 和 1.35×10。这一计算表明，在所有类别中，100 年内的超额癌症风险值最高。总的来说，K 放射性核素的 ECR 最高，最高的暴露途径是通过植物途径；然而，这些途径在 60 年内会转变为饮用水途径。本研究的结果可能有助于风险评估和公共卫生保护决策，以应对高水平辐射。
