南昌市城市饮用水水质健康风险评价

Health Risk Assessment of Drinking Water Supply in Nanchang

目的对南昌市市政出厂水和末梢水进行健康危害风险度评价。方法于2014年丰水期(4月)和枯水期(10月)对城区8个市政水厂和20个末梢水点各采集水样1次,丰水期水样检测常规指标,枯水期8个出厂水和2个末梢水再加测非常规指标,再筛选出可检出的指标,利用美国环保局推荐的水质健康危害风险评价模型计算水质健康危害风险。结果各类检测指标均合格,水中基因毒物质砷所致的健康风险度远大于躯体毒物质所致的风险度,占总风险度的99.9%,但均低于国际辐射防护委员会(ICRP)推荐的有毒有害物质健康危害风险最大可接受水平。丰水期水质健康风险度要高于枯水期,出厂水和末梢水水质健康风险度接近。结论南昌市市政出厂水和末梢水个人年健康危害风险水平在国际辐射防护委员会推荐的最大可接受风险水平范围内,砷的健康风险值要高于美国环保局建议的1.00×10^(-6)/a风险控制水平,为优先关注和治理的污染物。

Objectives To assess the quality and health risk of drinking water in Nanchang city. Methods Water samples were collected from centralized drinking water facilities. There were 9 conventional water quality parameters including iron,manganese,copper,zinc,arsenic,fluoride,nitrate- nitrogen and trichloromethane were examined in the rainy period（ April,2014）; while in the dry period（ October,2014）,a total of 9 unconventional water quality parameters including antimony,carbofuran,barium,nickel,ammonia- nitrogen,boron,molybdenum,dichloromethane and pentachlorophenol were added into the analysis list for 8 finished water and 2 terminal piped water samples. The health risks based on detectable substances in drinking water were assessed according to the assessment model recommended by the U. S. Environmental Protection Agency. Results The qualification rate of drinking water samples was 100%. The risk of genotoxic substance（ arsenic） was higher than non- genotoxic substance; the risk caused by arsenic was accounted for 99. 99% of total risks. The risk of each substance was lower than the maximal acceptable value recommended by the International Commission on Radiological Protection（ ICRP）. The health risk of drinking water samples collected in the rainy period was higher than that in dry period,and the health risk of finished water and terminal piped water were stayed in the same level. Conclusions The health risk of drinking water in Nanchang was in acceptable level recommended by the ICRP,but the risk value of carcinogen arsenic in drinking water was higher than the value recommended by USEPA（ 1. 00 × 10^（-6）/ a）,which should be preferentially concerned and controlled.