长江上游铜鱼体内全氟辛烷磺酸(PFOS)残留分布特征

为阐明长江上游鱼类全氟辛烷磺酸(PFOS)的残留分布,本研究于2013年分3次在长江上游不同江段,采集该地主要经济鱼类铜鱼(Coreius heterokon)。采用超高效液相色谱–质谱联用法分析铜鱼肌肉、肝和性腺3种不同组织全氟辛烷磺酸(PFOS)含量。结果表明,铜鱼组织内PFOS检出率为100%,总体均值为2.72 ng/g(0.33~10.14 ng/g)。PFOS含量水平在肝最高(5.56 ng/g),肌肉次之(1.39 ng/g),性腺最低(0.62 ng/g)。不同组织间差异极显著(K-W test,P0.01),表明鱼类肝比肌肉和性腺更易于积累PFOS。在不同采集江段,PFOS含量仅在肌肉组织差异显著(ANOVA,P0.05);在不同年龄组,PFOS含量有随鱼类年龄增长而增高的趋势,且在各组织中差异显著(ANOVA,P≤0.05),该结果表明PFOS含量可能与鱼类摄食内容及生理参数不同有关。与已有研究相比,长江上游铜鱼PFOS暴露水平低于国内外淡水、海水鱼类,目前仍处于一个较低水平。

Residual characteristics of perfluorinated sulfonate in Coreiusheterodon from the upper Yangtze River

Perfluorooctane sulfonate (PFOS) is a typical perfluorinated compound and a new environmental chemical pollutant found worldwide. PFOS is a potential threat to the environment and public health. Studies on PFOS pollution in China have focused on the aquatic environment and some aquatic marine organisms, but little attention has been given to wild populations of freshwater fish. The upper Yangtze River is inhabited by 112 en-demic and several rare fish species. However, the effect of PFOS pollution on fish in this area remains unclear. Brass gudgeon (Coreius heterodon), the main commercial fish species in this area, was sampled at Baixi, Yibin, Luzhou, and Chongqing cities in April, September, and December 2013, respectively, to clarify the status of PFOS residues in fish inhabiting the upper Yangtze River. A total of 36 brass gudgeon individuals were sampled, and PFOS content in 98 tissue samples, including three different fish tissues, were detected by ultra-performance liq-uid chromatography-tandem mass spectrometry. A mean value of 2.72 ng/g PFOS (range, 0.33–10.14 ng/g) was detected in all fish samples. The highest mean PFOS concentration was found in liver (5.56 ng/g), followed by muscle (1.39 ng/g), and the lowest concentration was detected in gonad (0.62 ng/g). A highly significant difference in PFOS concentration was observed among different tissues (K-W test,P<0.01).These results are consistent with some previous studies on PFOS concentrations in wildlife; that is, PFOS concentrates more easily in the liver than other tissues, which may be explained by the high binding affinity of PFOS for liver fatty-acid proteins. In addi-tion, muscle PFOS concentrations were significantly different among different river reaches (main effects ANOVA, P<0.05). The PFOS concentrations in all detected tissues increased significantly with increasing fish age (main effects ANOVA,P≤0.05), indicating that tissue PFOS concentrations may be related to food items or physiologi-cal parameters of different age groups of fish. The PFOS concentrations detected in brass gudgeon were lower compared with levels measured in species worldwide, indicating a relatively low level of PFOS pollution in fish species in the upper Yangtze River.