Dioxins, Dibenzofurans and Diphenyl ethers in the off-shore Yellow Sea coast of Korea- a case study

Abstract

Polychlorinated dibenzo dioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs), Polychlorinated biphenyls (PCBs) and Polybrominated diphenyl ethers (PBDEs) are Persistent Organic Pollutants (POPs) of considerable significance. Their contamination in environmental media is monitored with great concern for human and ecosystem safety. State-of-the art anytical methods were used in the congener-specific determination of these compounds in the surface sediments of Yellow Sea, collected from off-shore dump site zone (D), its neigbourhood (B) and in clean waters (A) of Korea. For comparative purposes sediment samples were collected from an inland bay (Masan Bay - MB) in Korea. In Yellow Sea 10 samples of clean area, 9 samples of near-contamination zone and 19 samples of contaminated dump site zones were collected. In Masan Bay 21 surface sediment samples were collected. The four groups of compounds were determined in all the sediments analysed. The sum of all detected congeners in each group revealed the following concentrations (pg/g dry weight) (average of various stations sampled). The highest levels were noted in Masan Bay for PCDDs and PCDFs viz. 686and 617 but in dump site zone for PBDEs (953). The investigation revealed that dump site contamination acts like a secondary source of pollution in Korean waters as shown in the concentrations and PBDEs patterns in dump site neihbourhood and as far south as close to Jeju island. On the other hand municipal wastes, ship trafficking and harbour activities were essential source of contamination in Masan Bay. The average concentrations of PCDDs, PCDFs and PBDEs in zone A (minimum levels) are: 132, 24 and 46 pg/g (dry wt.). Dioxin-like PCBs were determined in MB and D zones only. Clean waters revealed no such pollution whereas B zone had traces.Subsequent analysis of Masan Bay sediments for AH receptor binding in Hepatoma cell line (H4IIE) [indication of possible ecotoxicity] demonstrated high binding in samples that contai