Evaluation of ecological risk and primary empirical research on heavy metals in polluted soil over Xiaoqinling gold mining region,Shaanxi,China

(整期优先)网络出版时间:2010-04-14
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Soil,cropandresidents'hairoverXiaoqinlinggoldminingregion,China,whichwasselectedasacasestudy,weresampledandanalyzedforHg,Cd,Pb,Cu,Cr,AsandZnconcentrations.Theconcentrationsofheavymetalsinsoilorcropandhairsampleswereusedtoassesstheirpotentialecologicalrisks,ortofindtheresponsestothesemetalsasevidencestoprovethepotentialriskwascomingdowntoobservedharm,respectively.Theresultsshowedthat,thesemetalsinsoilwererankedbyseverityofecologicalriskasHg>Cd>Pb>Cu>Cr>As>Zn,basedontheirsingle-elementindexes.Intheviewofthepotentialecologicalriskindexes,ofallsoilsamples,abouthalfhadsignificantlyhighorhighpotentialecologicalrisk,whichcoveredmorethan74%ofthestudiedregion.Mostoftheriskswere97.41%fromHg,PbandCd,especially,84.37%fromHg.Boththesingle-elementandpotentialecologicalriskindexesindicatedthat,theecologicalriskgradeshadaspecialspatialcharacteristic,andincreasedfromnorthwesttosoutheastgenerally.Thiswasagreedwiththespatialdistributionofthestrengthingoldminingactivitiesoverthestudiedregion.TheconcentrationsofHgandPbwerehigherthantheirrelativebackgroundsinthecorps,andwereeven9.48and25.09timeshigherthantheirrelativebackgroundsinresidents'hair,respectively.Alltheseshowedthattheheavymetalsinthesoilhadahighpotentialecologicalrisk,especially,hadbeenaffectingthesecrops'growingandyield,andeventheresidents'healththroughfoodstrains.Obviously,thesemetals'potentialecologicalharmhadbeencomingdowntoobservedharmtotheecology.