Distribution characteristics and ecological risk assessment of heavy metals in surface sediments in Modaomen distributary mouth of Pearl River Estuary

This paper determined the concentrations of 7 heavy metals including Cu, Zn, Mn, Ni, Pb, Cr and Cd in 76 sediment samples collected from Modaomen estuary, and analyzed the distribution characteristics, sources, effects of sedimentary environment and ecological risk of these elements. The results indicated that Cu、Mn、Ni、Pb and Cd in the study area came mainly from the Modaomen, and Zn、Cr had various sources. Characteristic of sediment grain size was the main factor that influenced the distribution of 5 elements including Cu、Mn、Ni、Pb and Cr. The potential ecological risk of the study area was generally serious, and the ecological risk of the surface sediments was mainly caused by Cd.