The soil around the coal industrial area of East Junggar Basin in Xinjiang was studied. A total of 64 soil samples were collected from the 0-10 cm, 10-20 cm, 20-30 cm layers of soil profile, and the contents of Zn, Cu, Cr, Pb, Hg and As were tested, respectively. Pollution Load Index(PLI) was employed to assess the heavy metal contents and the model of health risk assessment recommended by USEPA was adopted to evaluate the health risk due to exposure to heavy metals in different soil depths. The multivariate statistical analysis, geostatistical analysis and GIS technology then were used to study the differences, spatial variability structure and distribution pattern of the evaluated results, and cross-validation method was adopted to assess the prediction results and its stability. The results suggested that the ranges of Zn, Cu, Pb contents were 46.06-48.00 mg·kg-1, 18.37-19.271 mg·kg-1 and 11.30-13.29 mg·kg-1, which did not exceed the standard compared with the background values of soil in Xinjiang. The ranges of Cr, Hg, As contents were 80.29-85.42 mg·kg-1,0.06-0.07 mg·kg-1,30.64-31.52 mg·kg-1, all of which exceeded the standard compared with the background values of soil in Xinjiang, and the exceeded rate was 60%. The values of PLI were in the order of PLI0-10 cm(1.35) > PLI20-30 cm(1.28) > PLI10-20 cm(1.25), which belonged to slightly polluted level. The values of HI were in the order of HI0-10 cm(2.53E-01) > HI20-30 cm(2.48E-01) > HI10-20 cm(2.43E-01), which indicated there was no non-carcinogenic risk. The values of TCR were in the order of TCR0-10 cm(2.81E-05) > TCR20-30 cm(2.80E-05) > TCR10-20 cm(2.74E-05), which was the acceptable level of carcinogenic risk. According to One -way ANOVA analyses, there was no noticeable difference in the PLI, HI, TCR (α is 0.863, 0.134, 0.056 respectively). Geo-statistical Analysis results implied that the regions with high contents of Zn, Cu and As were distributed near the coal industrial area and Northern part of study area in the 0-10 cm soil layer, Pb formed V-shaped high content ribbon, high content of Hg was located in the middle and Southern area, and high content of Cr was located in Coal Industrial Area and the anterior radial decline. High values of PLI, HI and TCR were found in north of the study area. The moderate pollution region of PLI decreased with the increase of soil depth, whereas HI and TCR showed no significant change. On the whole, high degree of heavy metals pollution and high possibility of health risk were mainly distributed around the six coal industrial areas which are in the high density population zone. Especially, the pollution of Cr, Hg, As was relatively serious and the health risk of As was the most serious which should be attached great importance to.
Keywords: geostatistial analysis; health risk; heavy metals; pollution load; soils.