Variation and source of heavy metals in surface sediment of Sanmen Bay in recent 10 years

To clarify the distribution and concentration of heavy metals in the surface sediments of the Sanmen Bay, Fujian, South China, Cu, Pb, Zn, Cd, Cr, As and Hg in the surface sediments of 82 stations in the Sanmen Bay waters in 2019 were analyzed. The concentration of the heavy metal elements were determined, and the data from 10 years ago were compared to show the changes in content of the elements, and their main material sources were analyzed. Results show that the average concentrations of Cu, Zn, Pb, Cd, Cr, As, and Hg in the surface sediments were 31.33, 96.46, 29.86, 0.116, 91.54, 13.09, 0.06 mg/kg, respectively, and Cu and Cr contents were higher obviously. Compared with 2009, the contents of Cu, Zn, and Cd in 2019 were generally consistent, while those of Pb, Cr, and As increased, and that of Hg decreased significantly. The contents of heavy metals in sediments decreased gradually from the nearshore to the sea, and the high-value areas were mainly concentrated near the mouth of the Shepan Waterway, Liyang Port, and Jiantiao Town. The principal component analysis and factor analysis showed that the sources of heavy metals were closely related to the impact of human activities.