Geochemical speciation and ecological risk assessment of heavy metals in surface soils collected from the Yellow River Delta National Nature Reserve, China

摘要

In this study, a comprehensive assessment of soil heavy metal (HMs) pollution in the Yellow River Delta National Nature Reserve (YRDNNR) was conducted. Spatial distributions, chemical fractions, and sources of eight HMs (Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni) in 46 soil samples in the studied region were analyzed. In addition, the potential risks of the HMs were evaluated. The results showed that the mean concentrations of Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni were 19.4, 65.2, 38.4, 55.9, 0.078, 41546.5, 510.3, and 27.5 mg kg(-1), respectively. It indicates that the concentrations of most HMs, with exception of Pb and Fe, in samples were similar to the background value of soil in China. Principal component analysis results showed that the HMs originated mainly from natural sources, but Pb pollution in the studied area was significantly caused by anthropogenic activities. In addition, Ecological risk assessment statistical analysis indicates that the HM contamination level in YRDNNR ranged from low to moderately polluted, however, the environmental risk due to Mn and Pb contamination was high.