Historical records of trace metals in sediments of the eastern Beibu Gulf, South China Sea.

In this study, trace metal (Cu, Pb, Zn, Cr, Cd, As, Hg, Ni, Li, and Co) concentration profiles along a sediment core were investigated to obtain background values and assess depositional trends and contamination levels in the Beibu Gulf. The EFs of all metals indicated no enrichment. The mean concentrations of all trace metals in the 10-6.5 ka phase could be considered the background values in the study area. Factor and principal component analyses indicated that the metals were mainly naturally sourced throughout the observed depositional period. Their geoaccumulation indices revealed that the sediments were not contaminated by trace metals.