天津表土PAHs区域环境风险评价研究

在参照国外相关标准基础上,应用指示克立格方法对天津地区表层土壤PAHs进行区域环境风险评价,并对评价结果进行比分析.结果表明,按照美国风险评价标准,只有组分Bap的含量超标,风险区域仅为8.12%和2.34%;按照荷兰风险评价标准,除了Ant和Baa的风险区域所占天津地区总面积的比重比较小之外(分别为5.26%和68.42%),其余所占比重都非常大,全部超过90%以上;按照加拿大风险评价标准,除了Nap的风险区域所占比重比较大(为97.89%)、Phe和Pyr所占比重中等(分别为56.84%和47.65%)之外,其余参与风险评价组分的风险区域所占比重都比较小,全部都在5%以下;按照丹麦(西兰岛)风险评价标准,只有组分Nap超标,且风险区域仅为9.26%.通过不同国家评价标准结果的比较,能充分了解天津地区目前土壤PAHs风险特征,对于制定符合天津地区特征以及符合中国特征的土壤PAHs风险评价标准具有重要的意义.

Regional Environment Risk Assessment and Probability Distribution of Topsoil PAHs in Tianjin Area

Based on some foreign standards of soil PAHs assessment, regional environment risk assessment of topsoil PAHs in Tianjin Area was discussed using the method of indicator Kriging. The results using different standards are also compared. It is shown that Bap is the only one component which exceeds the preliminary remedial goals and risk based concentration of U.S. in Tianjin area and the regions of exceeding standards are about 8.12% and 2.34% respectively. Most components of soil PAHs in Tianjin area are exceed the standard of Holland. The regions of exceeding standard are mostly 90% except the components of Ant (5.26%) and Bas (68.42%). Otherwise, the regions of exceeding Canada standard are mostly under 5% except Nap (97.89%), Phe (56.84%) and Pyr (47.65%). Based on the Soil Plan Zealand of Denmark, Nap is the only one component which exceeds the standard in Tianjin area and the region is about 9.26%. Comparing these risk distribution maps and spatial distribution maps of PAHs, it is found that the areas with high risk are mainly fallen in the areas with high concentrations of PAHs. The probability maps of PAHs risk are helpful for regional environmental management and planning.