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Marine pollution, ecotoxicology and sustainability
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Bioaccumulation and biomagnification of halogenated organic pollutants in marine biota from the Pearl River Estuary and South China Sea (Invited)
Monday 7th @ 0930-0950, Conference Room 7
Bixian Mai* , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences
Presenter Email: nancymai@gig.ac.cn |
| Marine organisms (fish and invertebrates) were collected from the Pearl River Estuary and South China Sea to investigate bioaccumulation and trophic transfer of halogenated organic pollutants (HOPs). Dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane Plus (DP), decabromodiphenyl ethane (DBDPE), 2,3,5,6-tetrabromo-p-xylene (pTBX) and pentabromotoluene (PBT) were detected in biota samples. The levels of DDTs, PCBs, and PBDEs showed sharp decreases, with more than 60% drops between 2005 and 2013. No clear temporal trends were found for the other HOPs. The concentration and contaminant pattern exhibited species-specific values in marine organisms. Habitat, feeding habit, and metabolic capability for xenobiotics can contribute to these species differences. The body burden of DDTs, PCBs and PBDEs was negatively correlated with the body length. Biota-sediment accumulation factors (BSAFs) for DDTs, PCBs, PBDEs, DP, DBDPE, pTBX, and PBT were 0.53-2.61, 0.79-10.31, 0.058-8.93, 0.031-0.043, 0.0018, 0.22, and 0.14. All the target compounds exhibited biomagnification, with biomagnification factors (BMFs) greater than 1 in the studied feeding relationships. The BMFs for PCBs increased with Kow at log Kow < 7.7, and subsequently decreased with a further increase of log Kow. However, a negative relationship was found for PBDEs. Food web magnification was found for PCBs, DDTs, PBDEs and DP, with trophic magnification factors (TMFs) of 2.76, 2.61, 2.20 and 2.31, respectively. Marine fish from Yongxing Island accumulated more POPs than those from Natuna Island, attributing to historical usage of POPs in the surrounding countries. Different POPs compositional profiles were found in marine fish from the South China Sea. The contribution of DDTs to POPs was higher than those of PBDEs and PCBs in marine fish from Yongxing Island, while PCBs was dominated in marine fish from Natuna Island. 31% of fish samples had values of (DDD+DDE)/DDTs lower than 0.5, suggested that fresh input of DDT exist in the environment of the South China Sea. Difference for POPs levels in Golden thread was observed among the sampling sites from the South China Sea. Levels of PBDEs and PCBs decreased gradually from eastern to western areas and from northern to southern areas; while no specific distribution for DDTs concentrations were found among the sampling sites. The hazard quotient values were lower than 1 for both PCBs and DDTs, suggested that consumption of marine fish in the South China Sea might not subject residents to significant health risk as far as PCBs and DDTs concerned.
Keywords: Halogenated organic pollutants; Marine organisms; Bioaccumulation; South China Sea
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