基于蒙特卡洛模拟的海河水体中^(238)U和^(232)Th的致癌风险评价及来源解析  

Source Apportionment and Carcinogenic Risks Assessment of ^(238)U and ^(232)Th in the Haihe River Using Monte Carlo Simulation

作　　者：武倩 朱兆洲[1] WU Qian;ZHU Zhaozhou(Tianjin Key Laboratory of Water Resources and Water Environment,Tianjin Normal University,Tianjin 300387,P.R.China;Department of Geography,Tianjin Normal University,Tianjin 300387,P.R.China)

机构地区：[1]天津师范大学天津市水资源与水环境重点实验室,天津300387 [2]天津师范大学地理学部,天津300387

出　　处：《湿地科学》2024年第6期930-939,共10页Wetland Science

基　　金：国家自然科学基金项目(41673026)资助。

摘　　要：为了研究海河水体中放射性核素^(238)U和^(232)Th的环境致癌风险和来源,采用固相萃取-电感耦合等离子体质谱法(ICP-MS),于2021年1月、4月、7月和10月,采集海河各段水样,测定水体中天然放射性核素^(238)U和^(232)Th的浓度;同时,基于Monte Carlo模拟,结合内梅罗综合污染指数法和致癌风险模型,对海河水体中^(238)U和^(232)Th的污染水平和致癌风险进行评价;采用Spearman相关系数法,结合正定矩阵因子分解模型(PMF),对污染源进行解析。研究结果表明,^(238)U和^(232)Th的活度浓度分别为(36.5±25.2)mBq/L和(0.041±0.037)mBq/L,^(238)U活度浓度明显高于^(232)Th;^(238)U活度浓度在1月最高,其次为4月和10月,在7月最低;在空间分布上表现出中、下游的活度浓度大于源河流和上游的规律;海河水体中^(238)U和^(232)Th在4月、7月和10月污染概率都未超过20%,在1月有较高的污染风险;从空间分布来看,海河源河流和上游的污染概率极低,中游和下游发生污染的概率在11%~14%之间;^(238)U和^(232)Th产生的致癌风险指数在10-6~10-4之间,存在潜在的致癌风险;^(238)U和^(232)Th对幼儿产生的总致癌风险最高,其次为成人,少年的风险最低;海河水体中^(238)U主要有4种来源,分别为农业源、工业源、宇宙射线和土壤源,其贡献率分别为61.4%、12.6%、8.9%和17.1%;^(232)Th的来源主要有3个,分别为工业源、宇宙射线和土壤源,其贡献率分别为18.1%、59.8%和22.1%。In order to research the environmental carcinogenic risks and sources of^(238)U and^(232)Th in the water of the Haihe River,Concentrations of^(238)U and^(232)Th were measured by ICP-MS.The pollution levels and carcinogenic risks of^(238)U and^(232)Th in the water of the Haihe River were evaluated based on a Monte Carlo simulation combined with the Nemerow Index and Carcinogenic Risk models.The source apportionment was fulfilled by Spearman’s rank correlation coefficient method and the Positive Matrix Factorization model(PMF5.0).The results showed that the activity concentrations of^(238)U and^(232)Th were(36.5±25.2)m Bq/L and(0.041±0.037)mBq/L in the water of the Haihe River,respectively.Activity concentrations of^(238)U were much higher than^(232)Th.^(238)U activity concentrations were highest in January,followed by April and October,with a minimum in July.The concentrations of^(238)U and^(232)Th in the middle and lower reaches were higher than those in the feeding rivers and upper reaches.The probabilities of pollution of^(238)U and^(232)Th were less than 20%in April,July,and October.However,there was a high risk of pollution in January.The probabilities of pollution in the feeding river and the upper reaches were extremely low.The risk of pollution occurring in the both middle and lower reaches ranged from 11%to 14%.The carcinogenic risk index in the Haihe River is between10^(-4)and 10^(-6),suggesting that there was a potential risk of cancer.The order of total carcinogenic risks was Children,Adults and Teenagers.The results of source apportionment showed that there were four pollution sources for^(238)U,namely,agricultural,industrial,cosmic rays,and soil.Their contributions were 61.4%12.6%,8.9%and 17.1%,respectively.There were three pollution sources for^(232)Th,that was,industrial,cosmic rays,and soil,with contributions of 18.1%,59.8%,and 22.1%,respectively.The scientific based for the prevention of uranium and thorium pollution in the Haihe River are provided from this work.

关 键 词：海河 ^(238)U和^(232)Th 污染特征 致癌风险 来源解析 

分 类 号：X591[环境科学与工程—环境工程]