次氯酸钠消毒饮用水中消毒副产物健康风险评估

Health risk assessment of disinfection by-products in drinking water disinfected by sodium hypochlorite

目的评估江苏省饮用水次氯酸钠消毒副产物水平及其人群健康风险。方法2017—2020年,采集使用次氯酸钠消毒处理工艺的水厂出厂水53份,检测出厂水中消毒副产物三卤甲烷(三氯甲烷、一氯二溴甲烷、二氯一溴甲烷、三溴甲烷)和卤乙酸(二氯乙酸、三氯乙酸)浓度,使用美国环境保护局(US EPA)推荐的健康风险评价方法,对成人饮水暴露消毒副产物的健康风险进行评估。结果饮用水中一氯二溴甲烷和二氯一溴甲烷具有潜在致癌风险,一氯二溴甲烷对成年男性和成年女性的致癌风险均为1.2×10^(-5)(1.4×10^(-7)~5.1×10^(-5));二氯一溴甲烷对成年男性和成年女性的致癌风险分别为8.2×10^(-6)(5.0×10^(-7)~5.7×10^(-5))和8.3×10^(-6)(5.0×10^(-7)~5.7×10^(-5))。太湖水源饮用水消毒副产物致癌风险高于江河水源。三卤甲烷和卤乙酸对成年男性和成年女性非致癌风险均远小于1。结论江苏省次氯酸钠消毒饮用水中三卤甲烷和卤乙酸致癌风险、非致癌风险均在可接受范围内,一氯二溴甲烷和二氯一溴甲烷是次氯酸钠消毒饮用水中消毒副产物风险管理重点指标。

Objective To investigate the contaminant level of disinfection by-products(DBPs)of sodium hypochlorite in drinking water and to estimate their health risks in Jiangsu Province,China.Methods A total of 53 finished water samples disinfected by sodium hypochlorite were collected from water plants in 2017 to 2020.The mass concentrations of DBPs including trihalomethane(trichloromethane,chlorodibromomethane,bromodichloromethane,and tribromethane)and haloacetic acid(dichloroacetic acid and trichloroacetic acid)in the samples were measured.The health risks of DBPs(trihalomethane and haloacetic acid)exposure in drinking water for adults were assessed using the health risk assessment method recommended by US EPA.Results Chlorodibromomethane and bromodichloromethane contributed the highest carcinogenic risk of the total carcinogenic risk.The carcinogenic risk of chlorodibromomethane exposure through drinking water was 1.2×10^(-5)(1.4×10^(-7)-5.1×10^(-5))for adult males and females.The carcinogenic risk of bromodichloromethane exposure through drinking water was 8.2×10^(-6)(5.0×10^(-7)-5.7×10^(-5))for adult males,and 8.3×10^(-6)(0.50×10^(-6)-5.74×10^(-5))for adult females.The carcinogenic risk of DBPs in drinking water was higher in Taihu Lake water source than that in river water source.The non-carcinogenic risks of adult men and adult women were far less than 1,respectively.Conclusion The carcinogenic and non-carcinogenic risks of trihalomethane and haloacetic acid in drinking water are accepted in Jiangsu Province.Chlorodibromomethane and bromodichloromethane are key indicators for risk management of DBPs in drinking water disinfected by sodium hypochlorite.