Spatial Distribution and Ecotoxicological Assessment of Heavy Metals in Bottom Sediments of Yellow River from Inner Mongolia, China.

The concentrations of Cu, Fe, Mn, Ni, Zn, Cr, Pb, and Cd in 37 samples collected from surface sediments from the Inner Mongolia section of Yellow River, China were discussed in order to estimate their distribution and pollution level. The measured metals in the sediments were found be in the range of Cu 10.28~45.54, Fe 18, 460.00~41, 880.00, Mn 448.90~919.83, Ni 8.52~67.39, Zn 60.93~149.40, Cr 65.69~149.67, Pb 0.50~19.98 and Cd 0.23~4.36 mg kg–1. The mean values of the heavy metal contents were arranged in the following decreasing order: Fe > Mn > Cr > Zn > Ni > Cu > Pb >Cd. Significant positive correlations were observed between the concentrations of Cu, Fe, Mn and Zn. Common sources and the identical behavior are observed in these heavy metals. PCA extracted two components with eigenvalues explaining 62.190% of the total variance. Cu, Fe, Mn, Zn, Cr had the natural origin controlled by the first factor. Anthropogenic causes are major sources of Pb and Cd. Ni could be affected by natural geological background and human activity. The higher values of Geo-accumulation index, enrichment factor, and PLI of Cr were attributed principally to anthropogenic activities. Fe and Zn did not lead to pollution. The Sediment contamination grade from the Inner Mongolia section in upstream of Yellow River was 0~1, belonging to from unpolluted to moderately polluted. [ABSTRACT FROM AUTHOR]