Study And Application Of Model Modification For Risk Assessment Of Contaminated Sites

With the advance of urbanization and the relocation of industrial enterprises, the city’s contaminated sites have become an important source of risk to human health. Compared to Europe, America and other developed countries, China’s health risk assessment of contaminated sites started late, and the existing technical guidelines refer mostly to foreign models and parameters. In order to make our risk assessment more suitable for China, the paper modifies exposure models and parameters of Technical Guidelines for Risk Assessment of Contaminated Sites of China.This paper proceeds from a health risk assessment, several international risk assessment models, including RBCA (Risk-Based Corrective Action) model of the US, CLEA (Contaminated Land Exposure Assessment) model in UK, and CSOIL (Contaminated Soil) model of Netherland, is selected to be analyzed on land and soil types, exposure pathways and models, risk characterizations and methods for determining remediation values of contaminated sites. Moreover, the paper briefly analyzes the Technical Guidelines for Risk Assessment of Contaminated Sites of China. After analysis of each model, the paper compares the differences between the Guideline and other models, and uses the Monte Carlo method to analyze the sensitivity of different parameters. Then, based on existing research results and experiences, the paper modifies parameters and models in the Guidelines and its exposure pathway of dermal contact with soil.At last, the paper selects a contaminated site of a chemical factory’s removal to apply the revised model and parameters to evaluate it, and compares the results with original model. The results show that the modified model results are lower than the original ones. The reasons may be that the revised parameters, including daily intake rate of soil, the exposure frequency and the PM10values, have all reduced. The rates of risk contribution show that each route of exposure is basically the same, which illustrated the revised parameters and model have certain rationality.