Study On Health Risk Assessment Of A Pharmaceutical Industry Contaminated Site

With the rapid development of social economy and the optimization and upgrading of industrial structure,a large number of high-pollution enterprises are facing relocation and closure.As an important land resource for urban development,these polluted sites not only seriously affect the development and reuse of land,but also cause serious harm to human health and the environment.How to more accurately assess the risks caused by polluted sites has become a hot topic in the field of environmental protection.In this paper,a pharmaceutical pollution site in Xuzhou is chosen as the research object,and its pollutants and filter values Xuzhou selected for research.Based on the national guidelines,the relevant parameters of the model were modified to analyze the rationality of the risk assessment results before and after the revision and the scope of contaminated site restoration.Based on the modified model parameters,the site was divided into three layers for assessment according to the characteristic of soil layers,and the impact of layered risk assessment and traditional risk assessment on the risk assessment results and restoration scope was compared and analyzed.The results are listed as following:(1)According to the data of Xuzhou National Physique Monitoring Bulletin,Xuzhou Statistical Yearbook,Environmental Bulletin and World Health Statistics Report,the parameters of height,weight,skin contact absorption factor and average time of carcinogenic effect in the guidelines were modified,and the risk control values of contaminated sites before and after revision were obtained.(2)A reasonable soil remediation target value was proposed by analyzing and comparing the calculated risk control value with the national standard,local standard and soil background concentration.It was found that compared with the calculation results of the guidelines before revised,the national and local soil screening values of benzene were larger,and the standards should be appropriately adjusted when selecting the screening values.Through the uncertainty analysis of exposure parameters,it is found that adult body weight,child body weight,average time of carcinogenic effect and indoor foundation thickness have great influence on the risk assessment results.(3)By comparing the risk contribution rates of each exposure pathway before and after the model parameter modification,it is found that the risk contribution rates of different exposure pathways before and after the model parameter modification change very little,indicating that the revised risk assessment results are reasonable and credible.The corrected risk control value is greater than the risk control value of the original guidelines.The corrected soil remediation area is reduced by about12954.75 m~2 compared with that before the correction,and the soil remediation amount is reduced by 34.38%.The area of groundwater restoration was reduced by5618.25 m~2 compared with that before the correction,and the amount of groundwater restoration was reduced by 8.79%.(4)According to the soil properties,the site was divided into three layers for layered risk assessment,and the soil remediation scope of different depths was drawn by Krigin interpolation method.The sensitivity parameters of the site feature parameters were found by comparing and analyzing the layered risk assessment results.Compared with the traditional risk assessment,the total remediation area and earthwork volume of the layered risk assessment were reduced by about 11572.25m~2and 17358.375m~3 respectively,the cost of repair has been reduced by about13.89-17.36 million yuan.which effectively lowered the remediation cost and time,reduced the remediation workload,and improved the site remediation efficiency.