基于ICE-SSD联用的地下水中苯并[a]芘生态风险评价——以下辽河平原地下水为例

ICE-SSD-based ecological risk assessment of Benzoapyrene in groundwater: A case study of Liao River Basin

借鉴地表水生态风险评价框架,尝试构建地下水生态风险评价方法,以下辽河平原地下水为例,开展地下水中苯并[a]芘(BaP)的生态风险评价工作.通过开展示范区地下水生态系统特征分析,筛选出用于地下水生态风险评价的代表性物种,共计5门9科.基于种间关系模型(ICE),推导地下水代表性物种的毒性数据.选取日本三角涡虫作为地下水典型物种,模拟地下水条件开展急性毒性试验,测试结果与模型推导数据间具有较好的一致性,初步验证了模型推导数据的可靠性;同时将测试结果应用于模型数据的校正,以降低方法的不确定性.基于此,构建地下水生态系统物种敏感度曲线(SSD);参考EPA方法构建地表水生态系统SSD曲线;地下水生态系统和地表水生态系统对于BaP 5%物种有害浓度(HC5)值分别为0.11μg·L^(-1)和0.58μg·L^(-1),初步表明地下水物种对BaP胁迫更为敏感.结合下辽河平原区地下水中BaP的暴露浓度水平,开展地下水生态系统风险评价,结果表明:处于高风险水平(RQ>1)的概率为0.61%,表明胁迫因子BaP对下辽河平原地下水生态系统影响有限.

In this study,a method of ecological risk assessment for groundwater was established,according to the ecological risk assessment procedure for surface water,based on which ecological risk assessment of Benzoapyrene（ BaP） in groundwater was carried out in Liao River Basin. Analyzing the ecosystem characteristic of groundwater in study area,representative species for ecological risk assessment were screened,including 5 phyla 9 families,the toxicity data of which were derived by interspecies correlation estimation（ ICE） model. Taking Dugesia japonica as typical species in groundwater and simulating the condition of groundwater,acute toxicity test was carried out. The test results in accordance with the data derived by ICE model verified the reliability of ICE-derived data. The ICE-derived data were revised using test results to reduce uncertainty. The species sensitivity distribution（ SSD）curves were plot for groundwater as well as surface water,hazardous concentration for 5% of the species（ HC5） derived by which were 0.11 μg·L（-1） and 0.58 μg·L（-1）,respectively. The results indicated that species in groundwater might be more sensitivity to BaP. Compared with BaP exposed concentration level in Liao River Basin groundwater,ecological risk assessment of BaP in groundwater was executed. The probability was 0.61% for high risk（ RQ〉1）,which indicated that the ecological risk of BaP in Liao River Basin groundwater was acceptable.