[Investigation on the content of persistent organic pollutants in fish from Dongting Lake in China].

Objective: To investigate the content of persistent organic pollutants (POPs) in fish from Dongting Lake. Methods: Ten sample collection points were set in lakeside city Yueyang and Yuanjiang. In July (wet season) and November (dry season) of 2012, 13 common fish species were captured by convenience sampling in Dongting Lake. Two to three fish with similar weight were selected in each season for the same species of fish. After sample preparation and pretreatment, the contents of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), indicator polychlorinated biphenyls and polybrominated diphenyls ether (PBDEs) in the samples were determined by high resolution gas chromatographer-high resolution mass spectrometry. Toxicity Equivalents (TEQ) of PCDD/Fs and dl-PCBs were calculated according to the revised toxicity equivalent factor (TEF) of WHO in 2005. The contents of POPs were expressed by median and quavtile. The differences of POPs in fish in different periods were compared by Wilcoxon rank sum test. Results: The content of PCDD/Fs of fish in Dongting Lake in wet season was 12.397 (8.865, 24.964) pg/g, higher than that in the dry season 0.771 (0.490, 1.442) pg/g (P<0.001), and the toxicity equivalent quantity (TEQ) were 0.150 (0.066,0.528) and 0.143 (0.066, 0.235) pg-TEQ/g without statistically significant difference (P>0.05). For the fish in wet and dry season from Dongting Lake,Σdl-PCBs of fish were 66.475 (28.065, 77.794) and 24.205 (18.237, 90.777) pg/g, respectively, and the TEQ were 0.061 (0.046, 0.268) and 0.075 (0.054, 0.182) pg-TEQ/g; Σ indicative PCBs were 237.764 (153.896, 335.483) and 119.711 (52.171, 408.696) pg/g, respectively; Σ PBDEs were 106.513 (64.834, 164.860) and 86.837 (61.872, 177.108) pg/g, respectively. The highest content of PCDD/Fs was found in grass carp (198.360 pg/g) in wet season. The higher content of PCBs was found in long-necked fish (2 332.509 pg/g) and PBDEs was found in pelteobagrus fulvidraco (343.857 pg/g), respectively. Conclusion: A lower burden was found in fishes from Dongting Lake, and the content of POPs varied in different seasons and fishes.