ANALYSIS OF SOURCES OF HEAVY METAL POLLUTION IN NEAR-SHORE SEDIMENTS

Heavy metals have been referred to as a kind of the most harmful pollutants in marine sediments due to their special geochemical properties, toxicity, high vulnerability and difficulty in management. Evaluation of the pollution level of heavy metals have been made by scholars with various proxies, such as geological accumulation index, enrichment factors, ecological risk index and pollution sources of the heavy metals based on elements correlation, principal component analysis, enrichment factor study and cluster analysis. As the result, preliminary qualitative understanding is achieved, but quantitative distinction on pollution sources of the heavy metals remain unsolved. Polycyclic aromatic hydrocarbon in sediments is regarded as a proxy of human activity for marine environment, while the element Ti, which is usually not enriched in marine environment, is mainly from continental rocks, soils, and their weathering products, and generally considered as the indicator of terrigenous clastic materials. Therefore, the correlations among heavy metals, polycyclic aromatic hydrocarbons and elements Ti can be effectively used to distinguish the heavy metal pollution source.