利用区间数表示水环境中污染物浓度的不确定性,构建了基于区间数的河流水环境健康风险评价模型.同时,采用专家咨询法建立模糊化的风险评价标准体系,将风险评价标准分为低、低-中、中、中-高、高和极高6个风险等级,并运用一级综合评判法得出健康风险评价的等级.最后,选取Cd、As、Hg、Pb、CN、NH3和挥发酚为评价因子,将基于区间数和模糊理论的河流水环境健康风险模糊综合评价模型应用于2005—2007年湘江长株潭段的水环境健康风险评价中.评价结果表明,2005—2007年湘江长株潭段的水环境健康风险水平较高;株洲和湘潭段的个人年风险值较大.其中,五星断面的个人年风险最高,儿童的个人年风险明显高于成人的个人年风险;2006年朱亭镇、霞湾、三汉矶和樟树港4个断面上个人年风险略有增高,2007年各断面的健康风险水平有所降低.
A fuzzy assessment model was developed to describe environmental health risks from water sources. The model uses interval numbers to represent contaminant concentration uncertainties and expert consultation to establish the risk assessment system. In the system, the risks were classified into six levels of "low", " low-medium", "medium", "medium-high", "high" and "very-high". Single-level comprehensive assessment was used to obtain the level of health risk assessment. On the basis of the interval numbers and fuzzy theory, an integrated fuzzy model for environmental health risk assessment of water sources was developed,and the model was used to assess the health risks associated with the Xiangjiang River in the Changsha-Zhuzhou-Xiangtan area. The selected parameters were Cd, As, Hg, Pb, CN, NH3 and volatile phenols. The results showed that the environmental health risk level of the Changsha-Zhuzhou-Xiangtan reaches was quite high from 2005 to 2007. The individual annual health risk of the Zhuzhou reaches and Xiangtan reaches were higher than that of the Changsha reaches,and the greatest individual annual health risk appeared in the Wuxing section. The annual health risk for an individual child was significantly higher than that for an individual adult. In 2006 ,the individual annual health risk in some sections was higher than that in 2005 ,while in 2007 the individual annual health risk in all of the sections was reduced.