Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN, 55804, USA.
Located at the Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, Oak Ridge Associated Universities, U.S. Environmental Protection Agency, 6201 Congdon Blvd, Duluth, MN, 55804, USA.
Arch Environ Contam Toxicol. 2023 Nov;85(4):390-403. doi: 10.1007/s00244-023-01038-6. Epub 2023 Nov 1.
Rainbow trout (Oncorhynchus mykiss) was exposed through the diet to a mixture of non-ionic organic chemicals for 28 d, followed by a depuration phase, in accordance with OECD method 305. The mixture included hexachlorobenzene (HCB), 2,2',5,5'-tetrachlorobiphenyl (PCB-52), 2,2',5,5'-hexachlorobiphenyl (PCB-153), decachlorobiphenyl (PCB-209), decabromodiphenyl ether (BDE209), decabromodiphenyl ethane (DBDPE), bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH), perchloro-p-terphenyl (p-TCP), perchloro-m-terphenyl (m-TCP), and perchloro-p-quaterphenyl (p-QTCP), the latter six of which are considered highly hydrophobic based on n-octanol/water partition coefficients (K) greater than 10. All chemicals had first-order uptake and elimination kinetics except p-QTCP, whose kinetics could not be verified due to limitations of analytical detection in the elimination phase. For HCB and PCBs, the growth-corrected elimination rates (k), assimilation efficiencies (α), and biomagnification factors (BMF) corrected for lipid content compared well with literature values. For the highly hydrophobic chemicals, elimination rates were faster than the rates for HCB and PCBs, and α's and BMFs were much lower than those of HCB and PCBs, i.e., ranging from 0.019 to 2.8%, and from 0.000051 to 0.023 (g-lipid/g-lipid), respectively. As a result, the highly hydrophobic organic chemicals were found be much less bioavailable and bioaccumulative than HCB and PCBs. Based on the current laboratory dietary exposures, none of the highly hydrophobic substances would be expected to biomagnify, but Trophic Magnification Factors (TMFs) > 1 have been reported from field studies for TBPH and DBDPE. Additional research is needed to understand and reconcile the apparent inconsistencies in these two lines of evidence for bioaccumulation assessment.
虹鳟鱼（Oncorhynchus mykiss）通过饮食暴露于非离子有机化学品混合物中 28 天，然后进行净化阶段，符合 OECD 方法 305。该混合物包括六氯苯（HCB）、2,2',5,5'-四氯联苯（PCB-52）、2,2',5,5'-六氯联苯（PCB-153）、十氯联苯（PCB-209）、十溴二苯醚（BDE209）、十溴二苯乙烷（DBDPE）、双（2-乙基己基）-3,4,5,6-四溴邻苯二甲酸酯（TBPH）、五氯对三联苯（p-TCP）、五氯间三联苯（m-TCP）和五氯对四苯（p-QTCP），后六种物质根据正辛醇/水分配系数（K）大于 10 被认为具有高度疏水性。所有化学物质均具有一级吸收和消除动力学，除了 p-QTCP，由于消除阶段分析检测的限制，其动力学无法验证。对于 HCB 和 PCBs，生长校正的消除率（k）、同化效率（α）和脂质校正的生物放大因子（BMF）与文献值非常吻合。对于高度疏水性化学物质，消除率快于 HCB 和 PCBs 的消除率，α 和 BMF 远低于 HCB 和 PCBs，即分别为 0.019 至 2.8%和 0.000051 至 0.023（g-脂质/g-脂质）。因此，高度疏水性有机化学物质被发现比 HCB 和 PCBs 的生物利用度和生物累积度低得多。根据目前的实验室饮食暴露情况，预计没有一种高度疏水性物质会生物放大，但 TBPH 和 DBDPE 的实地研究报告了营养级放大因子（TMFs）>1。需要进一步研究以了解和调和这两条生物累积评估证据之间的明显不一致。
