北京市朝阳区饮用水中三卤甲烷含量及其健康风险评估

Trihalomethane content in drinking water in Chaoyang district of Beijing and its health risk assessment

目的分析北京市朝阳区饮用水中三卤甲烷(THMs)的含量,评价其对人体的健康风险。方法于2021年枯水期(2-5月)和丰水期(6-8月),在朝阳区各市政水采样点采集市政末梢水样共216件。使用顶空-气相色谱法测定饮用水中4种THMs的含量,采用非参数检验(Wilcoxon配对法)比较枯水期和丰水期各组分的含量,采用健康风险评价方法进行评价。结果4种THMs浓度均符合GB 5749-2006《生活饮用水标准》的要求,合格率为100%,浓度关系表现为三氯甲烷(TCM)>一溴二氯甲烷(BDCM)>二溴一氯甲烷(DBCM)>三溴甲烷(TBM)。TCM(Z=-6.041,P<0.001)、BDCM(Z=-5.220,P<0.001)、DBCM(Z=-8.897,P<0.001)和TBM(Z=-5.830,P<0.001)浓度在枯水期和丰水期的差异有统计学意义。居民经饮水途径非致癌风险为5.21×10^(-2)(以成人计)和10.33×10^(-2)(以儿童计),处于可接受范围。居民经饮水途径致癌总风险为24.81×10^(-6)(以成人计)和49.21×10^(-6)(以儿童计),位于1.0×10^(-6)~1.0×10^(-4),存在致癌风险,THMs的健康风险以TCM为主。结论朝阳区饮用水中THMs存在一定健康风险,对于成人在可以接受范围内;儿童的健康风险值大于成人,应重点考虑儿童暴露于水中污染物质的健康风险。

Objective To analyze the content of trihalomethanes(THMs)in drinking water in Chaoyang district of Beijing,and assess its health risks to human body.Methods In dry season(Februrary-May)and wet season(June-August)of 2021,216 municipal end water samples from municipal water sampling points in Chaoyang district were collected.4 kinds of THMs were determined by hadspace gas chromatography,and the concentrations of these components in dry season and wet season were compared with non-parametric test(Wilcoxon matched pair technique),and evaluated by health risk assessment method.Results All of the concentrations of the above four THMs met the requirements of GB 5749-2006 drinking water sanitary standard,and the standard compliance rate was 100%.The concentration relationships of the four THMs were as follows:TCM>BDCM>DBCM>TBM.The result of statistical analysis was TCM(Z=-6.041,P<0.001),DBCM(Z=-5.220,P<0.001),DBCM(Z=-8.897,P<0.001),TBM(Z=-5.830,P<0.001).The differences of concentrations of the 4 kinds of THMs had statistical significance between dry season and wet season.The non-carcinogenic risk through drinking water was 5.21×10^(-2)(in adults)and 10.33×10^(-2)(in children),which was in the acceptable range.The total carcinogenic risk through drinking water was 24.81×10^(-6)(in adults)and 49.21×10^(-6)(in children),which is between 1.0×10^(-6)and 1.0×10^(-4),and there was carcinogenic risk.The health risk of THMs was mainly chloroform.Conclusions There are certain health risks of THMs in drinking water in Chaoyang district,but it is in acceptable range;The health risk of the exposure to pollutants in drinking water was higher in children than in adults,which should be taken into special consideration.