Heavy Metals Pollution Study And Health Risk Assessment In Soil Of Demolished Chemical Site

Heavy metals have the greatest potential to cause environmental problems on account of their extensive sources,hard-degradable characteristic,accumulation in the environment,and the toxicity to creatures and humans.With the acceleration of urbanization development,the plants that may have contaminated the environment are forced to move out of the city,the former sites are going to be used as residential or commercial land.However,the impact of the demolished sites on human health can't be ignored.Therefore,the main research of this paper aims to find out the pollution characteristics of the heavy metals on the demolished site and the impact on the ecological environment and human health.The main results are as follows:The heavy metals are accumulated at a certain degree with the most abundance of Hg.The average contents of As,Hg,Pb and Cr are 1.2,34.5,2.57,and 1.82 times of the background values of soil heavy metals in Jiangxi Province,respectively.Correlation analysis shows that a significant correlation between Pb and As,and a strong correlation between Pb and Cr,either.Clustering analysis results indicated sampling site No.1 belongs to a category of its own.The single factor pollution index showed that Hg was heavily polluted,and concentrations of As in partial sampling positions were exceeded the standard limits greatly.Nemerow pollution index stated that the pollution levels of As and Hg was serious,with the P_N values ranks at the order of Hg>As>Cr>Pb.The index of geo-accumulation results showed that the contaminations of Hg may mainly from human activities.The results of non-carcinogenic risk assessment showed that the index HIT was lower than 1 for adults,higher than 1 for children,the maximum value of HIT of children reached 5.16,which indicated that there was non-carcinogenic risk for children but not for adults.Meanwhile the general cancer risk index CRT were higher than the acceptable risk lever 10-6 both for adults and children,indicating that there were carcinogenic risks in the site,The non-carcinogenic and carcinogenic risk of children were higher than adults.The contribution rate of HIAs to HIT was about59%,CRAs to CRT was about 99%,therefore arsenic was the crucial factor for carcinogenic and non-carcinogenic risk.Conclusively,the present study has intensively studied the pollution characterization and health risk assessment on a demolished site in Nanchang which was a former chlor-alkali plant.On the basis of the obtained results,remediation measures are suggested for the further residential land use.