Risk Assessment Of Soil Heavy Metals In Different Functional Areas In The Suburbs Of Dadong District, Shenyang

This paper takes three different types of soil in the industrial cluster,the industrial gathering area,the whole vehicle core area and the living supporting area of the Dadong District of Shenyang as the research object,through the single factor and Nemerow quality evaluation method,Hakanson potential risk model and US EPA.The health risk model for quality assessment,potential and health risk assessment of soil heavy metals As,Cd,Cr,Ni,Hg and spatial analysis of health risk distribution based on ArcGIS software.the result shows:(1)The results of single factor evaluation of heavy metals are: heavy metal pollution degree from large to small Hg(severe pollution)> As(moderate pollution)> Cd(light pollution)> Ni(light pollution)> Cr(clean status).The pollution degree of heavy metal As is the living supporting area>industrial gathering area>the core area of the whole vehicle;Cd,Cr and Ni are the core area of the whole vehicle>the living supporting area>the industrial gathering area;Hg is the industrial gathering area>the living supporting area>the whole vehicle core Area.According to the results of Nemerow evaluation,the comprehensive pollution index varies from 1.31 to 46.35,with an average of 7.74.The industrial cluster(9.14)>the living supporting area(8.04)>the whole vehicle core area(5.64),and the three functional areas are Seriously polluted.(2)The single factor index ArcGIS map analysis shows that the pollution degree of As and Hg decreases from south to north and from west to east;the pollution degree of Cd and Ni decreases from south to north,and pollution from east to west decreases;Pollution to the north is reduced,but there is no significant difference in the east-west direction.Nemero comprehensive pollution index evaluation map shows that among the three functional areas,the industrial clusters are the most polluted,the living supporting areas are polluted second,the vehicle core area is relatively good,and Hg is the main pollution factor of the research area,which seriously affects the The overall pollution level of the region.(3)The potential risk single factor E of As,the core area of the vehicle> the industrial gathering area> the living supporting area;Cd,Cr and Ni are the living supporting areas> the whole vehicle core area> the industrial gathering area;Hg is the industrial gathering area> Car core area> living area.For the potential risk index RI,the three functional areas have reached a very strong risk,the living supporting area>the industrial gathering area>the whole vehicle core area,and the potential risk level of the whole research area has reached a very strong risk.The ArcGIS evaluation chart of potential risk RI shows that the maximum potential risk appears in the living supporting area,and the risk from south to north decreases in turn,and the risk from east to west decreases in turn.(4)The risk grades of four heavy metals are Ni>As>Cr>Cd,among which As,Cr and Ni exceed EPA standards,which do not exceed China's recommended standards,and Cd meets EPA standards.As,Cr and Ni in the three functional areas all have carcinogenic risks,and Cd does not have carcinogenic risk.As a non-carcinogenic hazard in the living area,the other two functional areas are less than 1,and the non-cancer risk index of Cr,Ni,Cd and Hg in the three functional areas is less than 1,which does not cause non-carcinogenic damage to the population.(5)The health risk analysis based on ArcGIS showed that the carcinogenic risk and non-carcinogenic risk of the three different functional areas were consistent in spatial distribution;the total health risk assessment showed that the first-level hazardous area accounted for 54.60% of the sampling area and 67.80%,the secondary risks accounted for 45.07% and 31.68% respectively,and the third-level risks accounted for 0.25% and 0.37% respectively,mainly concentrated in the central part of the core area of the vehicle and the northeastern part of the industrial cluster,level 4 The hazard ratios were 0.04% and 0.10%,respectively,and the five-level hazard accounted for 0.04% and 0.05%,respectively,all concentrated in the central part of the core area of the vehicle.