Research On Priority Control Factors And Health Risk Assessment Of Heavy Metal Pollution In Soil Around Mining Ares

The development and utilization of mineral resources have caused huge environmental risks and potential safety hazards.The problem of heavy metal pollution in soil is particularly prominent,which seriously threatens the ecological environment and human health.Due to resource and cost constraints,determining the priority control factors and pollution sources of soil pollution is the key to control and control soil heavy metal pollution.At the same time,in order to effectively control the health risks caused by soil heavy metal pollution,it is necessary to reasonably identify and quantify potential pollution sources and health risks.It is of great significance to carry out research on the priority control factors and health risk assessment of soil heavy metal pollution in mining areas for the source control of soil heavy metal pollution and pollution prevention and restoration.In this thesis,a copper mine in the Hetao area of Inner Mongolia is the research area,and field sampling will be carried out in the research area in 2020 and 2021,respectively.A total of 31 The soil samples of the surface layer,middle layer and lower layer were collected from each sampling point,and the contents of seven heavy metal elements were determined.The variation trend and spatial distribution characteristics of soil heavy metal content were analyzed,and the soil heavy metal pollution in the study area was evaluated based on the coupled simulation of potential ecological risk index method,geological accumulation index method,Monten Carlo-single factor index method and Nemero index method.The traceability analysis of heavy metals in soil was carried out by means of variation coefficient analysis method,accumulation coefficient analysis method,principal component analysis,correlation analysis method and PMF model.Health Risk Assessment Research.Explore the pollution characteristics,pollution sources and potential health risks of soil heavy metals in a mining area in the Hetao area of Inner Mongolia,and determine the priority control factors in the control of soil heavy metal pollution to identify and quantify key pollution sources and assess health risks.The impact of health risks,and to determine the priority control factors that contribute the most to health risks,in order to provide a scientific basis for the determination of the priority of control of heavy metal pollutants in the soil of mining areas and the prevention and control of pollution.This thesis draws the following main conclusions:(1)The content of the same heavy metals in the soil changed little with time in different sampling periods,and the change trend was stable with some decline.From the perspective of spatial distribution,the distribution patterns of As,Cu,Pb,Zn and Cd are basically the same in the horizontal distribution;while the content of the seven heavy metals has obvious differences in the vertical distribution,and there is a downward migration trend.(2)The comprehensive pollution evaluation results of Monte Carlo-single-factor index method show that the content of three heavy metals,As,Cu,and Pb,exceeds the standard according to the screening value,while none of Zn,Cd,Ni,and Cr exceeds the standard.Among them,the pollution level of Cu The highest;the Nemerow index method-Monte Carlo coupling simulation results show that the study area has reached the level of heavy pollution.Taking the soil background value in the Hetao area as a reference,the results of the geoaccumulation index method show that: Cu and Pb in the surface soil are moderately polluted,As,Zn,Cd are slightly polluted,Ni and Cr are non-polluted,and moderately polluted.The most polluted area is the surface layer,the middle layer,and the lower layer the smallest.The results of the potential ecological risk index method showed that the risks of Cd,Cu and Pb were significantly higher than those of other heavy metal elements;the risk index of the soil surface was significantly higher than that of the middle and lower soils,and the lower soil risk index was the smallest.In conclusion,the study area should strengthen the pollution prevention and control of Cu,Pb and Cd.(3)Source analysis results show that the pollution sources of soil heavy metals in the study area are mainly traffic pollution sources,agricultural pollution sources,natural parent material sources and tailings pollution sources,with contribution rates of 34.7%,9.3%,17.8% and 38.2%,respectively.(4)The health risk assessment results of the Monte Carlo-USEPA coupling simulation show that the study area has significant non-carcinogenic health risks to children,while adults are relatively safe;both adults and children have carcinogenic health risks.In addition,the source-oriented health risk assessment results showed that As and Cr were the priority control factors,and tailings pollution sources and natural parent material sources were the priority control pollution sources.