Dongling Smelter Surrounding Soil Heavy Metal Accumulation And Heavy Metal Pollution Assessment

Heavy metal pollution is produced by human activities, intentional or unintentional variety of heavy metals into the soil, leading to heavy metals in soil was higher than original content, environmental quality deterioration.Difficult to move the heavy metal ions, long-term retention and irreducible to the characteristics of the soil caused great damage to the ecological environment and soil to produce food is the main place of fruits and vegetables and other foods, heavy metals enter the body through the food chain ultimately, harm to human health.Donglingtai smelter in the production process in the form of point source emissions to the air a lot of lead, zinc and other heavy metals in the dust, serious pollution of the local environment. Fengxiang children's blood lead poisoning cases occurred. Donglingtai smelting company was identified as the major source of pollution, the surrounding villages in lead and zinc pollution in the health and life to people a lot of problems and hidden dangers. In this study, the soil around the smelter was in the Field sampling and laboratory analysis, and using the gray relational analysis of the region's quality of soil pollution levels were evaluated, in order to more accurately understand the extent of soil contamination of heavy metals, and the further application of single pollution index, Nemerow integrated pollution index, the Index of Geoaccumulation on surface soil levels of heavy metals were evaluated in order to get more reliable results.Finally evaluation of the local ecological risks of soil pollution and health risks. The main conclusions are as follows:(1) the horizontal direction, with increasing distance from the smelter, has emerged as the first heavy metal content generally increased (0-400 m), then decreased (400 m-700 m) the last stable (700 m～1500 m) of the distribution. Pb, Zn content in the area were the highest in the northwest, southwest, respectively, from the sources of pollution 50m～600 m,50m～400m range; Pb content of a maximum of 3.87 times the environmental quality standards (northwest) and 3.43 times (southwest), indicating that the northwest southwest Pb pollution was more serious, while the southeast, northeast, although the Pb content lower than the national quality standard, but higher than the background value, indicating that the soil under a certain external factors, is Pb, areas of high background values; in the study area the maximum Zn content of environmental quality standards for China's 0.85 times (northwest) and 0.66 times (southwest), Not excessive; elements Cr. Ni, Mn, Co and Cu contents were lower than the national quality standards, does not constitute a pollution, but the six elements were higher than the soil background values.(2) the vertical direction, in the southwest 300 meters away from the pollution profile of the sampling area, the main concentration of heavy metals in the soil surface, and their contents to the deep decline. One, Pb and Zn content variation similar,0cm～35cm between the layers of content by a big margin,35cm rapid decline in the future. In the context of 5cm～25cm, Pb were significantly higher than that of the soil environmental quality standards, are polluting elements, and Zn content and standards of environmental quality flat. Cr, Ni. Mn, Co and Cu layers in the profile changes of similar content, showed a downward trend in volatility, on the whole is not exceeded.(3) Soil quality assessment levels are as follows:Grey relational analysis concluded that the four monitoring sites in the southwest and northwest are IV, the upper limit of environmental quality standards; the southeast and northeast are 11, the second floor of environmental quality standards, reflecting the location of the smelter soil around the 300m has been a certain degree of pollution, especially the southwest and northwest more serious. Evaluation results for the single pollution index:smelter in different directions around the surface soil, Pb at a high level of contamination in the southwest and northwest to heavy pollution of soil Pb, Zn is non-pollution levels,, southwest and northwest the extent of pollution of heavy metals in the order of Pb> Zn, Cu, Cr, Ni, Mn, Co is not pollution. In the southeast and northeast are not all heavy metal pollution. Comprehensive pollution index Greater than 6, less than 12, indicating that the heavy metal pollution of soil has occurred. Nemerow comprehensive pollution index calculated concluded that the southwest and northwest heavy pollution; the southeast and northeast of the light pollution.(4) ecological risk assessment concluded that:Pb, Zn, Cu, Cr potential hazard index Degree of potential harm were:Pb and Zn strong, Cu and Cr minimal. Corresponding to the potential ecological risk Are:the northwest and southwest side to strong; the southeast and northeast are moderate.(5) health risk assessment concluded that:African soil around smelters carcinogen Pb, Zn, Cu, health hazards of the average personal risk, both adults and children. Children generally much higher than adults. HI (non-carcinogenic risk index) adult children are less than 1. Three non-carcinogenic health hazard to the average individual risk for adults:Children:That heavy metals every year in the region of non-carcinogenic pollutants affect the health of every 1.000 adults in less than 80 people; per 1,000 children, nearly 200 people.