Moermond Caroline T A, Roessink Ivo, Jonker Michiel T O, Meijer Thijs, Koelmans Albert A
Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, 6700 DD Wageningen, The Netherlands.
Environ Toxicol Chem. 2007 Apr;26(4):607-15. doi: 10.1897/06-288r.1.
It is not clear whether sequestration or aging of organic chemicals like polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) limits accumulation in higher levels of aquatic food chains. Therefore, the effect of aging on accumulation was studied in 1(-m3) model ecosystems that mimicked fish-dominated, macrophyte-dominated, and fish- and macrophyte-dominated shallow lakes. Also treatments without fish and macrophytes were included. General characteristics, biomasses, total (Soxhlet-extractable), and labile (6-h Tenax-extractable) PCB and PAH concentrations in sediment and biota were monitored over time. Accumulation data for PCB 28, PCB 149, and fluoranthene (native to the sediment taken from the field) were compared to those for spiked analogues PCB 29, PCB 155, and fluoranthene-d10. Labile fractions for spiked compounds were higher than for their native analogues and decreased over time, suggesting sequestration in the sediment. In the majority of cases, 6-h Tenax-extractable concentrations correlated better with concentrations in biota than Soxhlet-extractable concentrations. Ecosystem structure affected food web accumulation, but replicate variability was too high to detect clear treatment effects. Differences in accumulation between spiked compounds and their native analogues indicated an effect of aging for invertebrates, macrophytes, and benthivorous fish. Thus, aging may translate directly into reduced uptake at higher trophic levels.
尚不清楚多氯联苯（PCBs）和多环芳烃（PAHs）等有机化学物质的固存或老化是否会限制其在水生食物链较高营养级中的积累。因此，在1立方米的模拟生态系统中研究了老化对积累的影响，这些生态系统模拟了以鱼类为主、以大型植物为主以及鱼类和大型植物共同主导的浅水湖泊。还设置了没有鱼类和大型植物的处理组。随着时间的推移，监测了沉积物和生物群的一般特征、生物量、总（索氏提取法可提取）和不稳定（6小时Tenax提取法可提取）的多氯联苯和多环芳烃浓度。将多氯联苯28、多氯联苯149和荧蒽（取自野外沉积物中的天然物质）的积累数据与加标类似物多氯联苯29、多氯联苯155和荧蒽-d10的数据进行了比较。加标化合物的不稳定组分高于其天然类似物，且随时间下降，表明在沉积物中发生了固存。在大多数情况下，6小时Tenax提取法可提取的浓度与生物群中的浓度相关性比索氏提取法可提取的浓度更好。生态系统结构影响食物网的积累，但重复实验的变异性过高，无法检测到明显的处理效果。加标化合物与其天然类似物在积累上的差异表明老化对无脊椎动物、大型植物和底栖鱼类有影响。因此，老化可能直接转化为较高营养级的吸收减少。
