Study On The Health Risk Assessment-based Soil Repair Target Value For A Chromium-contaminated Site Of Qingdao

Determining of a site soil renovation target value which is environmental feasibleand economical is a basic element for choosing the solution of renovatingcontaminated field soil. Adopting health risk assessment，it’s a common way todetermine target value backward. Based on site investigation which considering offuture function and current situation this essay presents a health risk assessment on achromium-contaminated site. After studying and reviewing the key data in health riskmodel, the essay also determines the site target value. The main conclusions are asfollows:1．Pollution survey results show that the maximum content of total chromiumwas20410.9mg/kg in surface soil, and that of hexavalent chromium was6354.4mg/kg. The total chromium was contented in between392.5~20410.9mg/kg, withthe arithmetic average was10299.0mg/kg, and the geometry average was7885.7mg/kg; The hexavalent chromium in surface soil was contented in between34.9~6354.4mg/kg, with the arithmetic average was2524.2mg/kg, and the geometryaverage was1346.4mg/kg.2．Health risk assessment results show that the risks of cancer respectively were37.1E-06and58.3E-06in skin contact and breathing inhaled exposure ways. Thehexavalent chromium residue in the site has the potential risk of cancer to humanhealth. The site must be soil repair in order to reduce risk level.3．The target value was determined for43.00mg/kg for hexavalent chromium,and2.9x104mg/kg for total chromium.4．Through the repair target rationality analysis, we found that the existingassessing methods for health risks exist some problems. For instance, model cannotfully reflects the objective facts and model parameter selection is inflexible.