Geochemical characteristics of heavy metals in surface sediments of the Bohai Strait, China

The heavy metal (Cr, Cu, Ni, Pb, and Zn) content and particle size of surface sediment samples taken from 123 sites in the Bohai Strait of China were analyzed. All five heavy metals showed a similar distribution in the Bohai Strait, with lower concentrations in the middle and higher concentrations at the sides of the strait. The amount of heavy metals was lowest in the Laotieshan Channel due to the rapid current in this channel. According to our calculated values of the pollution index (Pi), only 1.6 % of the sample sites were polluted by Cr and Cu. The calculated geo-accumulation index (Igeo) values showed that few of the sites were polluted by heavy metals. The level of Pb was controlled by both terrigenous inputs and clay adsorption, while the levels of the other heavy metals (Cr, Cu, Ni, and Zn) were mainly controlled by terrigenous inputs.

Automated summary

We analyzed the heavy metal (Cr, Cu, Ni, Pb, and Zn) content and particle size of surface sediment samples taken from 123 sites in the Bohai Strait of China. All five heavy metals showed a similar distribution in the strait, with lower concentrations in the middle and higher concentrations at the sides. The Laotieshan Channel had the lowest heavy metal content due to rapid currents. Only 1.6% of the sample sites were polluted by Cr and Cu, according to our pollution index (Pi) calculations. Few sites were polluted by heavy metals based on geo-accumulation index (Igeo) values. Pb levels were influenced by terrigenous inputs and clay adsorption, while the levels of other heavy metals (Cr, Cu, Ni, and Zn) were mainly controlled by terrigenous inputs.