何魁核电站拟选厂址水体天然放射性核素分布特征及健康风险评价

为分析江西何魁核电站建设前附近水体天然放射性核素的分布特征及潜在健康风险,于何魁核电站拟选厂址及周边采集地表水样品5个、井水样品29个和泉水样品8个,分析^(238)U、^(232)Th、^(226)Ra和40 K含量,采用国际辐射防护委员会和美国国家环境保护局推荐的内照射剂量系数法,评估不同年龄人群经饮水途径摄入放射性核素的致癌风险。结果表明,研究区水体中238 U、232 Th和226 Ra的活度浓度均低于世界卫生组织饮用水水质标准,与国内外饮用水相比,其天然放射性处于偏低水平。放射性核素致癌风险在地表水中从高到低依次为:幼儿组(1.71×10^(-8)a^(-1))>成人组(3.99×10^(-9)a^(-1))>少年组(3.21×10^(-9)a^(-1));其在浅层地下水中依次为:幼儿组>少年组>成人组,均低于1×10^(-6)a^(-1)(美国国家环境保护局标准),但对幼儿致癌风险最大。本研究可为核电站运行后的辐射环境监测提供本底资料,并为核电站附近水环境安全提供科学依据和理论参考。

Distribution characteristics and health risk assessment of natural radionuclides in the water body in the vicinity of a proposed site of Hekui Nuclear Power Plant

To study distribution characteristics and potential health risks of natural radionuclides in the nearby water body before the construction of Hekui Nuclear Power Plant (NPP) in Jiangxi Province, five surface water, twenty-nine well water and eight spring water samples were collected from the proposed site of Hekui NPP, and activity concentrations of 238U, 232Th, 226Ra and 40K were analyzed. The internal radiation dose coefficient method recommended by the International Commission on Radiological Protection (ICRP) and the U.S. Environmental Protection Agency (U.S. EPA) was used to assess the carcinogenic risk of ingesting nuclides through drinking water in people of different ages. Results showed that activity concentrations of 238U, 232Th and 226Ra in the water body of the study area were lower than the World Health Organization (WHO) standards for potable water. Compared with research at home and abroad, activity concentrations of natural radionuclides in the water body of the study area was at a low level. The risk of cancer caused by radionuclides in surface water in the descending order was as follows: children group (1.71×10-8 a-1)> adult group (3.99×10-9 a-1)> juvenile group (3.21×10-9 a-1). The order in shallow groundwater was: children group > juvenile group > adult group. All of the risk values of carcinogenesis were lower than 1×10-6 a-1 (US EPA standard), but the risk children was highest. This study provides background data for radiative environment monitoring after NPP is built, and provides a scientific basis and theoretical reference for the safety of the water environment near NPPs.