The Characteristics And Risk Assessment Of The Heavy Metals In Soil And Foliar Dust Content And Isotopic In Xi’an Universities

This paper selects the campus soil and foliar dust of heavy metals of Pb, Cd, As, Hg and Cras the research object, using the ICP-MS analysis from September of2011to July of2012inthe12universities of Xi’an Eastern, West, South and northern suburbs in the heavy metals insoil and foliar dust and isotope seasonal distribution characteristics and regional distributioncharacteristics and pollution characteristics, and the use of environmental risk measures andhealth risk assessment method for evaluation of heavy metal pollution state. The results showthat:As and Cd content of3universities and3universities in Beijiao suburbs soil foliar dustthan the other3regions, which were19.09mg/kg and0.19mg/kg,20.78mg/kg and0.23mg/kg,in Shaanxi province is the soil background values of1.72times and2.02times,1.87times and2.45times; Pb and Hg content in soil and in3universities leaf surface dust than the other3regions, which were27.27mg/kg and0.15mg/kg,29.68mg/kg and0.16mg/kg, in Shaanxiprovince is the soil background values of1.27times and5times,1.39times and5.3times; thecontent of Cr3in the soil and foliar dust than the other3regions, respectively, for96.77mg/kg100.54mg/kg, Shaanxi Province is the soil background value of1.55times,1.61times.The average value of heavy metals in soil As, Pb, Cr, Hg and Cd were15.61mg/kg,25.97mg/kg,83.82mg/kg,0.128mg/kg and0.16mg/kg, the average value of foliar dust of heavymetals of As, Pb, Cr, Hg and Cd were18.61mg/kg,26.73mg/kg,85.09mg/kg,0.132mg/kg and0.19mg/kg. Content of heavy metals in soil is generally higher than that of heavy metals infoliar dust, heavy metals in foliar dust with the particle migration in the soil, is one of thesources of heavy metals in soil. Study on the content of pollution isotope showed that, Hg²⁰⁰ content, Cd¹¹², Cr⁵², Pb²⁰⁷inhigh concentration in their respective.Environmental risk analysis results show that, Xi’an city comprehensive environment5kinds of heavy metals in12colleges and universities in4regions of the risk index in the rangeof2.979-6.850, four regional environmental risk trend is on the eastern outskirts of southwestern north. Xi’an city comprehensive environment5kinds of heavy metals in12collegesand universities in4regions of foliar dust in the risk index is in the range of1.100-10.008, fourregional environmental risk trend is north eastern south west. Health risk assessment showedthat, Xi’an City,5kinds of heavy metals in the soil of A1（As, Pb, Cd, Cr and Hg） on the order ofhuman non-carcinogenic health impact damage from big to small Cr>As>Pb>Hg>Cd.3kindsof carcinogenic heavy metals on the order of human carcinogenic health impact damage frombig to small Cr>As>Cd. Heavy metals in3non carcinogenic pathways in the greatest harm tothe human body way is oral ingestion.