Bioaccumulation Of New POPs In Aquatic Organisms From The Yellow River Estuary

Perfluorinated compounds (PFCs) and hexabromocyclododecanes (HBCDs) were new persistent organic pollutants (POPs), which were used as alternatives for the discontinued POPs. Their environmental persistence, bioaccumulative properties, and potential toxicity were similar to those traditional POPs, however, study on bioaccumulation of PFCs and HBCDs had been just started in China. The purpose of this study was to investigate the levels of PFCs and HBCDs in several wild aquatic species from the Yellow River Estuary, North China, and to assess the extent of bioaccumulation for these pollutants in the wild aquatic species, as well as the trophic levels and dietary sources of them by calculating stable isotopes ratio (δ15N and δ13C).(1) PFCs were detected in all aquatic biological samples, the concentrations of PFCs ranged from 0.74-12.93ng/g wet weight, the highest (12.93ng/g) was found in Neptunea cumingi Crosse, and the lowest (0.74ng/g) in gross clams. In addition, PFCs concentrations in these aquatic organisms based on their dietary sources, followed carnivorous> omnivorous> filter-feeding. PFOA had the highest concentration in all PFCs homologues, accounting for 61.7% of all homologues in white clam PFOA, except PFOA, PFBA and PFDoDA also were much PFCs.PFOA-concentrations were greater than those of PFOS" in all aquatic organisms.(2) The concentration range of HBCDs was from 72.16 to 1043.95ng/g lipid weight, The lowest concentration was 72.16 ng/g (1w) in clam, the highest concentration was 668.22ng/g in conch. The conclusion drawn from the dietry sources of these aquatic organismes, HBCDs concentrations in carnivorous organisms were larger than those of omnivorous and filter-feeding. a-HBCD was the major HBCDs isomer, which account for 42%～93% of HBCDs, β-HBCD was not detected in some samples, and had also the lowest levels.(3) δ15N and δ13C were detected to analyze the trophic structure of studied aquatic organisms. As the result shown, the trophic structure of aquatic organisms determined the concentrations of PFCs and HBCDs in aquatic organisms. Generally, for aquatic organisms located in a same food chain (δ15N and δ13C were significantly linear related), the same pollution mode was shared and organic pollutants were biomagnified along with the food chain (without considering the process of biometabolism); while, aquatic organisms located in different food chains were exposed to different pollution modes and the diversity of contaminants levels were not related to the trophic level.