饮用水消毒副产物比较分析与健康风险评估

Comparative Analysis and Health Risk Assessment of Disinfection By-Products(DBPs) in Drinking Water

自来水消毒对于保障饮用水安全具有至关重要的意义,但是消毒过程伴随着消毒副产物的生成。基于已有的实际消毒方法应用案例,统计分析了液氯消毒、二氧化氯消毒、氯胺消毒、次氯酸钠消毒等消毒方法生成的三氯甲烷、一溴二氯甲烷、二溴一氯甲烷、三溴甲烷、二氯乙酸和三氯乙酸等典型消毒副产物生成量的平均水平,并对消毒副产物进行了人体健康风险评价。结果表明:次氯酸钠消毒副产物的健康风险水平最低(男性为8.34×10^-7,即每十亿人中834人有患癌症风险,女性为9.72×10^-7,即每十亿人中972人有患癌症风险),从健康风险评价的角度分析,次氯酸钠可能是目前较理想的液氯消毒替代品;在我国,南北方自来水中的三卤甲烷健康风险均大于EPA可接受水平(1×10^-6),南方(男性平均水平为1.53×10^-6,女性为1.79×10^-6)三卤甲烷的健康风险水平比北方(男性平均水平为1.44×10^-6,女性为1.68×10^-6)高;夏季(男性平均水平为1.56×10^-6,女性为1.82×10^-6)三卤甲烷的健康风险水平大于冬季(男性平均水平为1.10×10^-6,女性为1.28×10^-6)。

Disinfection of drinking water is very important to guarantee the safety of drinking water, but disinfection process is accompanied by the generation of disinfection by-products. Based on methods of water disinfected by liquid chlorine, chlorine dioxide, chloramine and sodium hypochlorite, average levels of DBPs such as trichloromethane, bromodichloromethane, dibromochloromethane, tribromomethane, dichloroacetic acid and trichloroacetic acid were counted, and the health risk of DBPs was evaluated. It was found that health risk level of the DBPs of sodium hypochlorite (male 8.34×10^-7 , that was 834 people per billion had cancer risk, female 9.72× 10 ^-7 , that was 972 people per billion had cancer risk) was lowest. So from the perspective of health risk assessment, sodium hypochlorite was the ideal substitute of liquid chlorine disinfection. Carcinogenic risk of trihalomethane in the north and south of China was greater than that of EPA acceptable level (1×10^-6 ), the risk of DBPs in the south (male 1.53×10 ^-6 , female 1.79×10 ^-6 ) was higher than that in the north (male 1.44×10 ^-6 , female 1.68×10 ^-6 ). In summer (male 1.56×10^-6 , female 1.82×10 ^-6 ), the health risk of trihalomethane was greater than in winter (male 1.10×10^-6 , female 1.28×10^-6 ).