The Dexing Evaluation Of Heavy Metal Pollution And The Spatial And Temporal Comparison Study

The current assessment and spatial-temporal contrast of heavy metals contamination were performed in Dexing areas within the scope of 4800km~2 .919 soil samples and 330 sediment samples were collected and analyzed for As, Hg, Cd, Cr, Zn, Cu and Pb. Heavy metal levels were determined using inductively couple plasma-atomic emission spectrometry, X-ray fluorenscence spectrometry procedures, and so on.According to 919 soil samples' data, the current assessment of heavy metals contamination in soils was performed using three methods, original testing data, pollution index and contamination degree, respectively. The contents of soil samples concentrated between 1.790～899 mg/kg for As, 0.034～4.980 mg/kg for Hg, 0.043~8.330mg/kg for Cd, 10～666 mg/kg for Cr, 25～18500 mg/kg for Zn, 6～1825 mg/kg for Cu, and 16～1312 mg/kg for Pb, respectively. The single-factor pollution index ranged from 0.119～30.967 for As, 0.227-5.900 for Hg, 0.215～13.471 for Cd, 0.111～4.773 for Cr, 0.250～63.000 for Zn, 0.171～7.071 for Cu, and 0.451～6.248 for Pb, respectively. The Nemerow pollution index ranged form 0.511～45.459. The contamination factor ranged from -0.881～58.933 for As, -0.773～32.200 for Hg, -0.785-40.650 for Cd, -0.889～6.400 for Cr, -0.750～184.00 for Zn, -0.829～51.143 for Cu, -0.543～36.486 for Pb, respectively. The contamination degree ranged from -4.038～265.497. The results of assessment indicated consistently that there were different extents of contamination of As, Hg, Cd, Zn, Cu and Pb, especially in the areas of the Dexing mines, coal mines along the lower courses Le'an river, coal mines in the northwest and the areas around battery factory.According to 330 sediment samples' data, the current assessment of heavy metals contamination in sediments was performed using three methods, original testing data, geoaccumulation index and potential ecological risk index, respectively. The contents of sediments samples reported concentrations between 3.070～1109 mg/kg for As, 0.015～5.430 mg/kg for Hg, 0.035～13.5mg/kg for Cd, 7～236mg/kg for Cr, 22～1770 mg/kg for Zn, 5～4390mg/kg for Cu, and 15～1685 mg/kg for Pb, respectively. The geoaccumulation index ranged from -2.667～5.83 for As, -5.129～3.371 for Hg, -3.1～5.492 for Cd, -3.585～1.490 for Cr, -3.483～2.847 for Zn, -3.672～6.106 for Cu and -1.787～5.025 for Pb, respectively. The potential ecological risk coefficient ranged...