Assessment Model of Landfill Sites Groundwater Environmental Health Risk Based on Stochastic Simulation-triangular Fuzzy Numbers

On the basis of US EPA health risk assessment method, and coupling the methods of triangular fuzzy number and stochastic simulation, the Stochastic Simulation-Triangular Fuzzy Numbers Model was built up and applied in groundwater environmental health risk assessment for a domestic waste landfill site in northern China as a case study. The results showed that the children's health risks of six monitoring wells all exceed the acceptable level, and the values of wells Z1 and Z2 distributed in Level Ⅲ and Level Ⅳ interval. The adults’ health risks of three monitoring wells also exceed the acceptable level, and the values of well Z6 distributed in Level Ⅴ and Level Ⅵ interval. Compared with that by the deterministic method, this model in a certain extent solved the uncertainty problem existing in the traditional deterministic evaluation process. It could not only calculate the risk level of groundwater pollution, but also quantitatively obtain the corresponding probability level, providing more accurate assessment information of the health risks for the decision makers and more basis for the groundwater pollution management.