[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.