Preliminary Study On Polybrominated Diphenyl Ethers In Wild Fish From The Tributaries Of The Three Gorges Reservoir Area

Polybrominated diphenyl ethers(PBDEs) are one class of efficient flameretardants which are extensively used in a range of applications including textile,electronics and ornaments. PBDEs are now becoming the focus due to its persistent,highly lipophilic and bioaccumulation. There have been quite some investigations ofthe distribution, fate and risk assessment of PBDEs in the environment at home andabroad. However, so far, little information about these emerging contaminants in theThree Gorges Reservoir area is available. The concentrations and distributions ofPBDEs in38species of fish samples from the Three Gorges Reservoir area wereanalyzed in this paper.The results show that: PBDEs congeners were detected in38species of fish,indicating their ubiquitous distribution in the Three Gorges Reservoir area. Totalconcentrations of fourteen PBDEs(BDE-17,28,71,47,66,100,99,85,154,153,138,183,190and209)in all samples ranged from0.62ng/g lw to32.28ng/g lw, withmedian and mean values of7.14ng/g lw and10.03ng/g lw, respectively. The averagelevel of∑14PBDEs in samples from Changtan River, Modaoxi River, Daning River,Yangtze Fengjie, Pengxi River, Tangxi River were10.84,8.62,8.52,4.49,4.26,2.16ng/g lw, respectively. PBDEs levels in muscle tissue this area is lower than that inother areas in China, such as the Pearl River Delta and the Liao River. BDE-47,BDE-209and BDE-138were the major congeners in all samples, contributing22.65%,21.23%and21.92%to the total concentration, respectively. However, highcontributions of BDE-209were found to be same with the commonly detected patternin fishes from other regions of the China, which may be related to use of a largenumber of deca flame retardants. The concentrations of BDE-47, BDE-66, BDE-100,BDE-99, BDE-154, BDE-153, BDE-138and BDE-183, showed significantcorrelations with each other (p<0.05). But the correlation between BDE-190,BDE-209and other congeners was not statistically significant. Significant correlationbetween the lower brominated diphenyl ethers show that different regions of the fish may have the same sources, which may come from the use of penta and octabromodiphenyl ether products. But on the other hand, the residual concentration ofPBDEs in different fish and different homologue distribution patterns indicatedifferent exposure pathways.All the PBDEs congeners except BDE-85were detectable in the samplesindicating that the skin tissue is widely exposed to these pollutants. The Σ13PBDEsranged from11.71to187.06ng/g lw, with median and mean values of26.24ng/g lwand39.77ng/g lw, respectively. BDE-47, BDE-138and BDE-209were thepredominant congeners in all samples, accounting for8.17%,19.06%,60.75%,respectively. The proportion of BDE-138seemed to be relatively high which wasdifferent from the result in other studies around the world but consistent with theresults in muscle tissue. The relative abundance of BDE-209may suggest thatDeca-BDE sources existed in studied area. The average concentrations of BDE-209inskin tissue were approximately21times higher than those of muscle tissue. This maybe related to the structural characteristics of skin and their living habits. Theconcentrations of BDE-71, BDE-47, BDE-66, BDE-100, BDE-99, BDE-154,BDE-153, BDE-138and BDE-183, showed significant correlations with each other(p<0.05). But the correlation between BDE-190, BDE-209and other congeners wasnot statistically significant. These results consistent with those reports of muscletissue.Oral exposure assessment shows that the value of estimated daily intakes ofPBDEs for muscle and skin were0.037,0.181ng/kg body weight/day, respectively.The LOAEL value calculated by Darnerud was5-6orders of magnitude higher thanthe results of this research. The potential human health risks posed via fishconsumption was negligible.Triclosan(TCS) is a synthetic, broad-spectrum antibacterial agent incorporated ina wide variety of household and personal care products. It is the halogenated organicpollutants like PBDEs and PCBs. TCS can be transformed into potentially more toxicand persistent compounds, such as methyl triclosan. So far, it is rarely reported thatTCS and MTCS can be detected simultaneously. A gas chromatography coupled with mass spectrometry (GC/MS) method was developed for the simultaneousdetermination of TCS and MTCS in fish sample. Parameters affecting bothderivatization and clean-up procedures were studied. After extracting with hexane andactone(V:V=1:1), cleaning-up with Gel Permeation Chromatography (GPC) and silicagel packed column, the residues were derivatized with Acetic Anhydride and analyzedby GC/MS. Under the optimal conditions, linear range was5-500pg/μL for TCS and2-500pg/μL for MTCS. The correlation coefficient(R)was above0.99for the analytes,with the1imit of detection (LOD)1.3and0.8pg/μL, respectively. Good recoveries(83%-89%for TCS and85%-98%for MTCS) were achieved in the spikingexperiments. The established method was successfully applied to determine thisanalytes in real fish samples.