Research On The Impact Of A Lead-zinc Mining Area In Daxin, Guangxi Province On Its Surrounding Environment And Population Health

[Objective] To determine the situation of heavy metal pollution in the mining area’ssurrounding environment,then evaluate the level of heavy metal pollution of the studyarea and exposed population’s hairs. To determine the situation of heavy metal loadsin local residents’ body,and the heavy metal loads on the health effects of localresidents.This may provides a theoretical reference for the environment protection andagricultural production in this mining area and its surrounding environment andimprove local residents’awareness of self-protection.[Methods] This paper choosed a lead-zinc mining area’s surrounding environment inDaxin， Guangxi Province as the research scope using of investigation andexperimental methods.Informations were investigated in the field.To determine thesituation of heavy metal pollution and local residents’ health in the studyarea.Arranged sample points in the study area.19water samples，21crops samples andcorresponding38soil samples,15human hair samples were collected and ICP-AESwas used to analyze heavy metal elements including Cd, Cu, Cr，Pb, Zn and Mn ofthese samples. Set up the paper’s database by Excel and use SPSS16.O for basicstatistical description and deduction by chi-square test,t test,variance analysis andother methods.Use Arcgis9.0to draw the geographical map of the study area,samplingpoint arrangement maps and the spatial distribution map of the situation of heavymetal pollution of soil.The single factor pollution index and the comprehensivepollution index were used to evaluate the level of heavy metal pollution of samples.[Results](1)Heavy metal contents of soil samples exceed evaluation criteria atdifferent levels.The order of over standard rates of heavy metal in soil samples is Zn＞Cd＞Pb＞Cu＞Cr.Pb，Zn and Cd accumulate heavily in the soil of the study area，especially in abandoned lands.(2) Heavy metal contents of drinking water samples donot exceed evaluation criteria.The drinking water can’t affect people’s health.(3)Contents of Cd，Pb，Zn in water samples from irrigation ditches exceed evaluationcriteria at different levels，those of Cr and Cu do not.Cd，Zn and Pb accumulateheavily in irrigation ditches，especially in Asegment.Contents of Cd，Pb，Zn and Mnin sediment samples exceed evaluation criteria,those of Cr and Cu do not.Cd，Zn andPb are the main pollution elements which accumulate heavily in the study area’ssediment.(4)Contents of Cd，Cr and Pb in crops samples exceed evaluation criteria，those of Zn and Mn do not. The order of enrichment abilities to heavy metal in cropssamples is the axle algae＞chjcories> chards> sweet potato leaves.(5)Contents of Cd，Pb，Zn，Cu and Mn of soil show the trend of zonal distribution in the studyarea.Contents of Cr of soil show the trend of nubby distribution.The situation of heavymetal pollution are not fully consistent with regularities of distribution of heavy metal.(6)Of those22people who have been checked the bodies，males’ prevalence rates ofbone hyperplasia are much higher than that of females,the difference is statisticallysignificant (p＜0.01).The differences of prevalence rates of bone pain，brown ringaround eyes，swollen and twisted joints of males and females have no statisticalmeaning(p＞0.05).(7)Contents of Cr,Mn in hairs exceed evaluation criteria atdifferent levels，those of Cd，Cu，Pb and Zn do not.The average of contents of Pb inhairs of people under40years old during people of different ages is the highest (p＜0.01).The differences of contents of heavy mental in hairs of males and females haveno statistical meaning(p＞0.05).(8)By observing physical examination data aboutcontents of Cd in urine organized by the local government in2001,about43.48%people’s contents of Cd in urine exceeded evaluation criteria.Contents of Cd in urineand contents of Cd exist positive relativity(r=0.609,p＜0.05).(9)The single factorpollution index and the comprehensive pollution index were used to evaluate the levelof heavy metal pollution.Analytic results of water，soil and sediment samples areconsistent with each other，as a whole，it shows the serious combined pollutioncharacteristic which Cd，Pb，Zn mainly pollute and Cu，Mn，Cr follow.Chjcories andchards of crops samples in the study area are mainly contaminated by Cd,Cr andPb,sweet potato leaves and the axle algae are not contaminated.Contents of Cr and Mnin human hairs samples exceed evaluation criteria，the highest concentration of Pb isclose to the evaluation criterion.[Conclutions](1) The lead-zinc mining area has had a negative impact on itssurrounding environment and population health.(2) The study area has beencontaminated by Cd in2001，villagers’health got hurt.(3) It shows that since2001themining area has been closed，the pollution which local population are exposed to isbecoming less than before.Positive measures such as unified distributing foodorganized by local government， the introduction of qualified drinking water andcadmium removing in vitro，having a good effect on villagers’health.