Spatial and vertical distributions of sedimentary halogenated polycyclic aromatic hydrocarbons in moderately polluted areas of Asia

Abstract

The sedimentary halogenated (chlorinated and brominated) polycyclic aromatic hydrocarbons (Cl/BrPAHs), PAHs, and elements were analyzed to investigate contamination processes and sources. Assessments were conducted in sediments from three sites: surface sediments from the Yellow Sea and sediment cores from Kandy Lake and Negombo Lagoon, Sri Lanka. Most of ClPAHs targeted were detected in all sediments. Spatial distributions of total ClPAH concentrations in the Yellow Sea showed the presence of multiple hot spots that differed from those of total PAHs. In Kandy and Negombo sediments,total ClPAH concentrations were slightly higher in surface layers than in bottom layers; the opposite trend was observed for PAHs. Principal component analysis showed that the clusters of most ClPAHs were similar to those of anthropogenically derived elements, but were far from those of PAHs. Consequently, ClPAHs in sediments appear to be persistent contaminants, which may make them appropriate as indicators of anthropogenic sources.