Bioaccumulation Of Dechlorane Plus: Compared With Polybrominated Diphenyl Ethers In Sediment From Yongning River Within An E-waste Dismanting Plant In Taizhou,southeastern China

Dechlorane Plus（DP） is a classical polychlorinated flame retardant,which has been widely used in wires, cables, computers, plastic and many other polymer materials. Increasing studies have found that DP and its related compounds（including Mirex、DPMA、Dec 602、Dec 603、Dec604 、 a Cl10-DP 、 a Cl11-DP） can be ubiquitously detected in various environmental matrices and biological samples. In the present thesis, the concentrations of nine DP and related compounds were analyzed in the sediment-aquatic organism group samples collected from a river near a classicalelectronic waste dismantling area in the southeast of China（Yongning River, Taizhou）. Meanwhile, bio-sediment accumulation factors（BSAFs） were calculated in order to evaluate their biological availabilities. Moreover, the concentrations and BSAFs of polybrominated diphenyl ethers（PBDEs, including BDE 28, BDE 47,BDE 99, BDE 100, BDE 153, BDE 154, BDE 183, BDE 209） in the collected sampleswere also studied for comparison purposes. The main results are as follows:1. All Dechlorane Plus and its related compounds（DPs） exceptDPMA（53.85%） and Mirex（84.62%） were 100% detected in the sediment samples from Yongning River, Taizhou. The concentrations of total DP, Mirex, DPMA, Dec 602, Dec 603, Dec 604, αCl₁₀-DP, αCl₁₁-DP were 21.99-5894.00 ng/g dry weight（dw）, BDL-14.71 ng/g dw,BDL-2.05 ng/g dw, 0.031-37.80 ng/g dw, 0.016-1.13 ng/g dw, 0.63-79.41ng/g dw, 0.051-4.07 ng/g dw, and 0.15-258.92 ng/g dw, respectively. The concentrations of Σ₈BDEs were 303.13-26838.3 ng/g dw, which were similarto those of the previous reports. These contaminant levels of DPs and PBDEs tested in the sediment samples from Yongning River were at medial or high of global level. The component analysis suggested that PBDEs in the studied areas possibly originated from the commercial products of Deca-BDE and Octa-BDEs. While for DP, although its commercial products can not be confirmed, fanti =（anti-DP/（syn-DP+anti-DP）） values in all sediment samples do not varie significantly,implying that DP pollution in the tested area are of similar sources.Moreover, DP does not seem to have gone through significant chemical and/or biological activities, or these corresponding activities have no stereoselectivities.2. The concentrations of DP and its related compounds in aquatic organisms were in the order of Mirex> DPMA> DP（anti-DP> syn-DP）>DP analogues（Dec 602> Dec 604> Dec 603 or Dec 604> Dec 602> Dec603） > dechlorination products of DP(αCl₁₁-DP> αCl₁₀-DP). Thedistribution patterns of these compounds were similar to other studies but obviously different from those of the sediment, implying that DP and its related compounds have different abilities of bioaccumulation. The concentrations of Total-DP, Mirex, DPMA, Dec 602, Dec 603, Dec 604,αCl₁₀-DP, and αCl₁₁-DP in aquatic organisms were BDL-406.83 ng/g lw,BDL-8447.97 ng/g lw, BDL-1489.60 ng/g lw, BDL-35.27 ng/g lw,BDL-29.46 ng/g lw, BDL-158.49 ng/g lw, BDL-5.18 ng/g lw, BDL-14.60ng/g lw, respectively, and are at low or medial levels of reported data. The concentrations of Σ₈BDEs are 7.73-11925.85 ng/g lw, similar to previous results. The fanti values in biological samples variesa lot, which may attribute to the selective biological accumulation or metabolism of the two isomers.3. The average BSAFs of Total-DP, Mirex, DPMA, Dec 602, Dec603, Dec 604, αCl₁₀-DP, and αCl₁₁-DP in aquatic organisms are 0.0087±0.0014, 5.92±0.62, 4.94±1.10, 0.21±0.054, 1.22±0.28, 0.06±0.03,0.43±0.0014, 0.018±0.0018. Based on the values of BSAFs calculated,DPMA and Mirex in the sediments from Yongning River can be accumulated by aquatic organisms. However, DP as well as other DP related compounds have no obvious bioaccumulation. More specifically,the bioaccumulation capabilities of these compounds were in the order of DPMA> Mirex> Dec603> αCl₁₀-DP> Dec602> Dec604> αCl₁₁-DP> DP.In the case of PBDEs, most of the homologues were of certain capabilityof bioaccumulation except BDE 209 and BDE 183. These results agree with previous reports. Moreover, the interspecific differences in BSAFs may relate to the living habitats and diets of the organisms. Moreover, the plots of BSAFs versus LogK_ow suggest that the bioaccumulation capabilities of DPs and PBDEs relate to the Kow values of the compounds.It is also found that bioaccumulation of these chemicals is positively correlated with LogK_ow when LogK_ow is less than 8, and shows are verse trend when LogK_ow is higher than 8.