城市水环境健康风险评价

Spatial and Temporal Health Risk Assessment of Water Environment in Urban Area

传统的水质化学监测等级评价体系能够客观反映水体的污染物水平,但无法直接反映水体污染物对人体健康的潜在危害。利用美国环境保护署(U.S.EPA)提出的水质健康风险评价模型,评价某市2001-2005年5个水质监测站周围水体中所含污染物对人体健康潜在危害的时空差异和源特征。结果表明,该市水体中所含污染物对人体健康潜在危害较大,72%的水质监测样本对人体健康潜在危害超过了国际辐射委员会(ICRP)推荐的最大可接受限值5.0×10-5a-1;水体污染主要发生在2001年、2003年和2005年,且主要集中在1#和2#水质监测站周围地区;化学致癌物是该市水体中危害人体健康的主要风险来源,各污染物对人体健康危害的风险度排序为:As>Cr+6>Cd;水体中非致癌污染物风险度排序为:F>Pb>Cu>NH3-N>Hg>CN-1>酚,在研究期内未对暴露人群构成明显的健康危害。水环境健康风险评价模型较传统的水质等级评价体系能够更直观地表征水体中各污染物对人体健康的潜在危害,有利于明确水体污染物治理的优先顺序,为水环境管理提供科学依据。

Water pollution intensity can be objectively quantified by traditional Chinese classification system of water quality,however,this method can not directly disclose the human health risk exposed to water pollutants.In this paper,the spatial-temporal differences of human potential exposure risks to water pollutants were evaluated by using the water environmental health risk assessment model developed by U.S.EPA and the source contribution of these risks over five water quality monitoring sites from 2001 to 2005 was analyzed.The results reveal that water pollution situation of study area is very serious,as the health risk values caused by 72 percents of monitored water samples exceeds the guideline threshold（5.0×10^-5a^-1）,recommended by ICPR,of human health risk.The greater human exposure risks happed in year 2001,2003,and 2005 and located in monitoring site 1^# and 2^#.The results also indicate that chemical carcinogens are the major roots of human health risk exposed to water pollution in study area during the study period,while no health risk is caused by the non-carcinogens.The order of carcinogens causing human health risk is As〉Cr^＋6〉Cd,when,for non-carcinogens,the order is F〉Pb〉Cu〉NH3-N〉Hg〉CN^-1〉hydroxybenzene.Overall,the results suggest that water environmental health risk assessment model could be better identify the human health risk exposed to water pollutants,compared to traditional Chinese classification system of water quality.The research results could also help policy maker to ascertain the priority of water pollutants need to be treated