2018-2020年某市饮用水中消毒副产物监测结果及风险评估

目的 了解某市城区生活饮用水中消毒副产物的分布,并对其进行健康风险评估.方法 2018-2020年对该市城区市政出厂水消毒副产物进行监测,按照美国环保局推荐的健康风险模型进行风险评估.结果 出厂水中共检出三氯甲烷、一氯二溴甲烷、二氯一溴甲烷、三溴甲烷、二氯乙酸、亚氯酸盐、氯酸盐等11种消毒副产物,其含量均符合《生活饮用...

Surveillance results and risk assessment of disinfection by-products in drinking water in a city,2018-2020

Objective To investigate the distribution of disinfection by-products (DBPs) in drinking water in urban area of a city, and to evaluate their potential health risk. Methods DBPs in municipal supply water in this city from 2018 to 2020 were monitored, and risk assessment was conducted according to health risk assessment model recommended by the United StatesEnvironment Protection Agency (USEPA). Results Eleven kinds of DBPs, including trichloromethane, chlorodibromomethane, difluorobromomethane, bromoform, dichloroacetic acid, chlorite, and chlorate were detected in drinking water, and the concentration of above-mentioned DBPs detected was lower than the standard limits specified in the Standards for Drinking Water Quality (GB 5749-2006). Chlorate could be detected in water disinfected by non-chlorine dioxide, with a high detection rate and a high concentration. The contents of trihalomethanes and haloacetic acids were also high in water except chlorate. The concentration of chlorate in wet season was higher than that in dry season(Z=-3.814, P<0.001), and no statistically significant differences were found in the other DBPs in dry season (P>0.05). Among factory water samples with groundwater as the source of water, the concentration of trihalomethanes was lower in water samples disinfected with chlorine dioxide than in water samples disinfected with chlorine, but the concentration of chlorate was higher in water samples disinfected with chlorine dioxide than in water samples disinfected with chlorine (P<0.05). The carcinogenic risk of DBPs was 1.42×10^-5 per year, and the non-carcinogenic health risk was3.23×10^-2per year. Trichloromethane contributed the most to both carcinogenic andnon-carcinogenic risks. Conclusion Chlorate, trichloromethane and haloacetic acids are the principal DBPs in drinking water in urban areas of this city, and the carcinogenic and non-carcinogenic risks of DBPs are all within an acceptable range. Trichloromethane is the major contributor to the health risk, and should be the focus of risk management.