呼和浩特市城区饮用水和环境放射性水平测量与评估

发布时间：2018-03-18 01:26

本文选题：呼和浩特市　切入点：放射性核素　出处：《内蒙古医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的(1)调查呼和浩特市城区全部水厂出厂水的放射性活度水平,估算由饮水摄入放射性核素所致居民内照射年均有效剂量。(2)确定呼和浩特市城区表面土壤中天然及人工放射性核素活度浓度,测量环境辐射水平,评估对居民产生的健康风险。方法采用现况调查和实验室相结合的方法。(1)在呼和浩特市城区的全部9个水厂采集水样,用低本底α、β放射性测量仪测量总α和总β的放射性活度;用高纯锗γ谱仪测量~(226)Ra、~(40)K的活度浓度;用电感耦合等离子体质谱法分析U含量;用快速测量水氡方法检测水氡浓度。(2)采用高纯锗γ谱仪对呼和浩特市城区48个表面土壤样品进行放射性核素的测定;用环境γ剂量率仪测量环境辐射水平;与世界和我国土壤中放射性平均水平进行比较,通过联合国原子辐射效应科学委员会和相关文献推荐的方法估算居民受照剂量,评估终身致癌风险。结果(1)呼和浩特市城区出厂水中总α活度浓度的范围是0.016~0.491 Bq/L,总β活度浓度范围的是0.046~0.519 Bq/L;~(226)Ra、~(40)K的活度浓度范围分别是0.002~0.027 Bq/L和0.010~0.210 Bq/L;U含量范围是2.2~4.7 ug/L;水氡含量范围是0.13~6.20 Bq/L;居民通过饮水摄入总α放射性所导致的内照射年均有效剂量的范围为0.034~0.063 mSv/年。(2)呼和浩特市表面土壤样品中~(238)U、~(232)Th、~(226)Ra、~(40)K和137Cs活度浓度平均值分别为29.29±12.95、39.33±4.34、29.77±3.21、650.49±62.21、1.62±1.53 Bq/kg;测量的γ辐射空气吸收剂量率为86.32±11.92 nSv/h,该地区居民受到室内外γ辐射空气吸收剂量率所致的年有效剂量为672.11μSv/a;终身致癌风险为2.52×10~(-3)。结论(1)呼和浩特市城区出厂水的总α和总β的活度浓度低于国家标准指导值;~(226)Ra、~(40)K的活度浓度低于世界卫生组织(WHO)的指导值;U的含量低于WHO规定的限值;居民饮水所致内照射年均有效剂量在安全水平之下。(2)呼和浩特市表面土壤中天然放射性活度浓度和环境辐射处于正常均值范围内,对居民造成的健康风险非常低。
[Abstract]:Objective 1) to investigate the level of radioactivity of all water plants in urban area of Hohhot. Estimating the average annual effective dose of radionuclides absorbed in drinking water for residents) determining the activity concentrations of natural and artificial radionuclides in the surface soils of urban areas of Hohhot and measuring the environmental radiation levels, Methods Water samples were collected from all 9 water plants in the urban area of Hohhot, and the radioactivity of total 伪 and total 尾 were measured by low background 伪, 尾 radioactivity meter. High purity germanium gamma-ray spectrometer was used to measure the activity concentration of 40 K, and the content of U was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). High purity germanium 纬 spectrometer was used to measure radionuclides of 48 surface soil samples in urban area of Hohhot, and environmental radiation level was measured by environmental 纬 dosimeter. Compared with the average levels of radioactivity in the soils of the world and China, the radiation doses of the inhabitants were estimated by the methods recommended by the United Nations Scientific Committee on the effects of Atomic radiation and the relevant literature. Results 1) the range of total 伪 activity concentration was 0.016 ~ 0.491 Bq / L, and the range of total 尾 activity concentration was 0.046 ~ 0.519 Bq / L ~ 0. 0020.027 Bq/L and 0.010 ~ 0. 210 Bq 路L ~ (-1) U in water, respectively. The range of radon content is 0.13 ~ 6.20 Bq 路L ~ (-1); the average annual effective dose caused by drinking water intake of total 伪 radiation is 0.034 ~ 0.063 mSv/ / L ~ (-1)) the average activity concentration of Rn in soil samples of Hohhot is 29.29 卤12.95 ~ 39.77 卤3.21 ~ (65) 0.49 卤62.21 ~ 1.62 卤1.53 Bqkg 路kg ~ (-1), and the average activity of 137Cs is 29.29 卤12.95 ~ 39.77 卤3.21 ~ (0.49 卤62.21) Bqkg-1 路kg ~ (-1), respectively, in the surface soil samples of Hohhot city, and the average values of radon concentration are 29.29 卤12.95 ~ 39.33 卤4.3429.77 卤3.21 卤6.21 卤1.53 Bqkg-1 路kg ~ (-1), respectively. The absorbed dose rate of 纬 -radiation air is 86.32 卤11.92 nSv / h, the annual effective dose caused by indoor and outdoor 纬 -radiation air absorbed dose rate in this area is 672.11 渭 Sv / a, and the lifetime risk of carcinogenesis is 2.52 脳 10 ~ (10) ~ (-3)%. Conclusion the total 伪 and. The activity concentration of total 尾 is lower than that of the national standard guidance value, the activity concentration of 40K is lower than that of WHO (WHO) and the content of U is lower than the limit specified by WHO. The annual effective dose of internal irradiation caused by drinking water of residents is below the safe level. 2) the natural activity concentration and environmental radiation in the surface soil of Hohhot are within the normal mean range, and the health risk to the residents is very low.
【学位授予单位】：内蒙古医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R123.1

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