The geochemical characteristics and the source of heavy metals in sediment for the Beibu Gulf

The environmental background values for Cu, Zn, As, Pb, Hg, Cd in the Beibu Gulf are measured by the investigation data obtained in 2007, and their difference from background values of the South China Sea and terrigenous soil are also studied.The trend analysis of heavy metal contents in surface sediments and core sediments in the Beibu Gulf shows that in recent 100 a,the contents of Cu, As, Hg and Cd in coastal sediments are basically increasing; the trends in the middle of the Beibu Gulf are complicated; heavy metal contents in the sediments of the mouth of the gulf are stable. According to the distribution and trends of the heavy metal contents in sediments, it is qualitatively concluded that the environmental behaviors of heavy metals in the Beibu Gulf are affected by the human activity in Guangxi coastal areas, among which Cd, Hg, As are deeply affected. The main sources of heavy metals in the Beibu Gulf are terrigenous input from Guangxi, ocean currents via Qiongzhou Strait also contributed to heavy metal inputs.