Study On Heavy Metal Pollution Distribution In Sediment And Soil In Realgar Mining Area And Analysis Of Residents' Health Risk Perception

In recent years,the heavy metal pollution in soils caused by the industrialization has attracted wide attention worldwide.The long time mining of realgar will cause serious soil pollution and may damage the health of local residents.Therefore,it is of great significance to understand the distribution and pollution level of heavy metals in the soil of realgar mining area for the prevention and control of heavy metals pollution in the soil of the mining area.Meanwhile,it is very important to understand the current residents'perception for the risk of soil arsenic pollution,which is very significant for strengthening self-protection awareness of soil pollution.In this research,by collecting soil samples from a realgar mining area in Hunan Province,we analyzed the content and the distribution of seven heavy metals,such as As,Cd,Cr,Cu,Zn,Ni and Pb,and their correlation with soil physical and chemical properties.The main forms of arsenic in soil and the effects of soil physical and chemical properties on their morphology were also studied.Nemerow index method and Hakanson potential ecological hazard index method were used to evaluate the pollution degree and ecological environmental risk of heavy metals in the soil of realgar mining area.According to two questionnaires surveys for the residents from local realgar mining area and the residents from circumjacent area,the awareness,attention and risk perception of residents for soil heavy metal pollution and soil arsenic pollution were investigated.The results show that average concentration of 7 heavy metals in the soil of this realgar mining area are in the order of As>Zn>Cr>Pb>Cu>Ni>Cd,in which As and Cd are the main pollutants,and As content in all sampling areas is beyond national soil quality secondary standard.The correlation coefficient between As and Cd is as high as 0.998,and the correlation between As and Cd and NH₄⁺-N in soil is very significant.Pollution assessment shows that the closer to the mining area,the higher the potential ecological risk of arsenic is.The main forms of arsenic in this mining area are iron arsenate and calcium arsenate,and the proportion of residual arsenic is small.The results of the questionnaire surveys show that the residents from local mining area have high risk awareness of soil pollution and arsenic pollution,and their attention and related knowledge about soil pollution protection are relatively high,while the residents from circumjacent area have low awareness about the relevant issues and their attention is generally low.