The Pollution And Risk Assessment Of Heavy Metals In Soil Of The High Cancer Area Of Huai River Basin

This paper choses Shicao, a village of Zhoukou as the object of the study. It is located in ShayingRiver basin, which is the biggest tributary of Huai River. In recent years, along with the increasingpollution, the incidence of the cancer has increased year by year. This paper based on field investigation,collecting soil samples and laboratory analysis, analyses with ICP-MS to determine6kinds of heavymetals(Cu, Cr, Cd, Zn, Ni, Pb)content in soil, discusses the spatial distributions of heavy metals in soil,pollution and health risks. The main contents include:Part Ⅰ: the overview of soil heavy metal pollution as well as the purpose and significance of thestudy.Part Ⅱ: the main content of soil heavy metal pollution, research progress as well as therelationship between heavy metal pollution and health.PartⅢ: investigation of regional environment, including natural environment, the level ofdevelopment of agriculture and social economy, the main environment problems.Part Ⅳ: the main research methods in the study, including the laboratory sample collectionmethod, processing method and data processing and analysis.Part Ⅴ: analysis of soil heavy metal content and spatial distribution characteristics in study area.Part Ⅵ: analysis of soil heavy metal pollution and space assessment in study area, including thesingle heavy metal pollution assesment, Nemerow comprehensive pollution assessment, potentialecological risk assessment and health risk assessment.PartⅦ:summarize conclusion. The conclusions are as follows:(1) In the study area, the average content of soil heavy metals in the dry season is higher thanthat in rainy season.6heavy metal elements in the dry season from high to low: Zn＞Cr＞Pb＞Cu＞Ni＞Cd；6heavy metal elements from high to low: Zn＞Cr＞Ni＞Pb＞Cu＞Cd.6heavy metal elements in thedry season belongs to the same component, Except Cd, the other five elements show a significant positivecorrelation, Cd and other5heavy metal elements are also significantly related, the dry season is likely tohave the same soil heavy metals pollution sources. The6heavy metals in soil in rainy season has3maincomponents, and there is no correlation between the rainy season and dry season of heavy metals, so thesources of pollution in the rainy and dry seasons are different, Compound pollution is serious in the soil.(2) In the rainy season and dry season of the study area,single soil heavy metal pollution indexmean value is less than1, the rank of single heavy metal pollution index in the dry season is Ni> Cu> Cr>Zn> Cd> Pb, in the rainy season is Ni> Cu> Cr> Zn> Cd> Pb. Ni, Cu and Cr during the dry season, CrNi and Cd in the rainy season, sample has reached the level of minor contamination, a few more tomoderate pollution degree. In the study area the average Nemero comprehensive pollution index of soilheavy metals in the dry season is0.71, which has reached the warning level, some samples to slightpollution. The mean value is0.53in the rainy season, which belongs to the security level, the partial samplebelongs to the alert level.(3)In the dry season and rainy season of the study area soil heavy metal potential ecological riskindex mean value is less than30, except the middle potential ecological risks of Cd samples, the other5were belonged to slight risk. The potential ecological risk index, in the dry season was Cd> Pb> Cu> Ni>Cr> Zn, in the rainy season was Cd> Pb> Ni> Cu> Cr> Zn. And their spatial distribution characteristicsare consistent with the content of the spatial distribution of heavy metals, high content of heavy metal’s potential ecological risk is high. In the dry season and rainy season integrated ecological risk index ismoderate ecological risk, the number of samples in dry season at moderate risk are up to78%, the numberof samples in rainy season at moderate risk are up to56%, dry season to achieve a strong risk is up to6%,the rainy season is23%. The rest are slight risk.(4)In the study area single and comprehensive non carcinogenic index of the soil heavy metalduring the dry season and rainy season are less than1, non carcinogenic health risk is small, carcinogenichealth risk index and the total index are less than soil governance standards（10-6） recommended byUSEPA, but the carcinogenic risk index and the total index of some Cr samples are higher than（10-6）, onthe whole, attention should be paid that Cr is the main carcinogenic risk contribution factor, and it would beexist some health risk.