Geochemical Appraisal of Chemical Weathering and Metal Contamination in Coastal Surface Sediments, Off Northwest Hainan Island, the Gulf of Tonkin

Coastal sediments not only contain a majority of trace metals, but they also act as a source of dissolved metal ions to the overlying water column. Distinguishing the level of trace metal enrichment from the natural input in sediments is therefore important to determine the distribution and sources of land-derived detritus and pollutants in the coastal region. This study investigates fine (2) for As, Cd, and Pb, suggesting that the sediments were likely enriched by these elements. A comparative study of trace metals concentrations and EF with other coastal regions of China, however, revealed that the study area is in a pristine environmental condition compared to other coastal regions of eastern China. Factor analysis identified three dominant sedimentological and geochemical associations, accounting for ∼70% of total variance, recognize terrigenous input, heavy mineral role and anthropogenic input in controlling the distribution of most elements in the study area.