Pollution Status And Risk Assessment Of Heavy Metals In Soils Of Chemical New Material Industrial Park In Zhenjiang

Soil is the earliest means of production developed and utilized by human beings.It is also the material basis for human survival and the source of precious wealth.As one of the main pollutants in soil,heavy metals have a great impact on soil environmental quality,and can cause harm to human health through food chain enrichment.Therefore,the pollution status and risk of heavy metals in regional soil have attracted great attention.The industry types of Zhenjiang Green Chemical New Materials Industrial Park involve chemical raw materials,electroplating,fine chemicals and bio-energy.There are more than 60 electroplating enterprises in Zhenjiang Environmental Protection and Electroplating Professional Zone.In this paper,the main heavy metals in soils and vegetables of different industrial zones were analyzed and detected,the pollution status of heavy metals in the industrial park was studied,and the ecological and health risks related to heavy metal pollution were preliminarily discussed.The results show that:(1)The contents of Cr,Ni,Cu,Cd,Pb and Zn in soil of Zhenjiang New Green Chemical Industry Park were 72.90,34.95,30.55,0.19,19.05 and 138.45 mg/kg,respectively.Referring to the Standard for Risk Control of Soil Pollution in Agricultural Land of Soil Environmental Quality(GB15618-2018),the average values of Cr,Cu,Cd,Pb and Zn are lower than the standard.Comparing with the heavy metals in the soils of other urban industrial zones in China,it is found that the heavy metals in the soils of Zhenjiang New Green Chemical Materials Industrial Park are in a moderate pollution level.(2)The results of soil ecological risk assessment in Industrial Park showed that the average cumulative index of soil heavy metals was Ni>Cr>Pb>Cd>Cu>Zn,and the order of individual potential ecological hazards was Cd>Ni>Pb>Cu>Cr>Zn.Judging from the average value of the comprehensive potential ecological hazard index,the total ecological hazard is slight.The contribution rate of Cd element to the ecological hazard of each sampling point is the largest,followed by Ni,and the contribution rate of Zn element is the smallest.The elements of Cr,Ni,Cu,Cd and Pb have some homology,but the correlation between Zn and other five heavy metals is not strong.(3)The results of heavy metals detection in the main vegetables in the Industrial Park showed that the average contents of Cr,Cu,Zn and Cd in the vegetables in the industrial park were lower than the food hygiene standard limits,and the average contents of Ni and Pb were between the critical values of the food hygiene standard limits.The average contents of Cr,Cu,Cd,Zn and Pb in rapeseed were lower than the limits of food hygiene standards,and the average contents of Ni exceeded the limits of food hygiene standards.The average contents of Cu,Cd,Zn and Pb in radish were lower than the limits of food hygiene standards,while the average contents of Cr were between the critical limits of food hygiene standards,while that of Ni exceeded the limits of food hygiene standards.(4)The results of vegetable health risk assessment in the Industrial Park showed that the average comprehensive pollution index of heavy metals in green vegetables was 0.84,and Ni was in a mild pollution state,while the other five heavy metals were in a non-pollution state.The average comprehensive pollution index of heavy metals in rapeseed was 1.46.Ni and Cr were slightly polluted,while the other four heavy metals were non-polluted.The average comprehensive pollution index of radish is 1.31.The elements of Cr and Ni are slightly polluted,and the other four heavy metals are non-polluted.The pollution degree of heavy metals in three vegetables was rapeseed > radish > green vegetables.There was a significant positive correlation between heavy metal Cu and Pb in Chinese cabbage and soil Cr,Ni,Cu,Cd,Pb,but no significant correlation between heavy metal elements in rape and radish and soil heavy metal elements.