Laboratorio de Ecoloxía Mariña (LEM), Universidade de Vigo, Campus Universitario, Crta. Colexio Universitario s/n, Vigo, Galicia, Spain.
Aquat Toxicol. 2011 Mar;102(1-2):48-57. doi: 10.1016/j.aquatox.2010.12.012. Epub 2010 Dec 28.
It is well known that dissolved organic matter binds metal ions and buffers them in natural waters. Although it is believed that a decrease in metal ion concentration should lead to a decrease in metal bioavailability, previous work has shown that Pb uptake by Mytilus edulis gills is greatly enhanced in the presence of humic acids. In the present work, the effect of more soluble organic matter (fulvic acids and DOM extracted from river) on Pb uptake by mussels and their gills is studied. Pb complexation by these organic substances was measured by anodic stripping voltammetry (ASV) and it is proven that Pb uptake by mussel gills in the presence of fulvic acids can be successfully predicted according to ASV-labile Pb concentrations. However, Pb uptake by whole mussels in the presence of river DOM is slightly higher than predicted on the basis of ASV measurements. The possible reasons leading to different effects of DOM on Pb uptake by mussels are discussed according to physicochemical properties of DOM.
众所周知，溶解有机质可以结合金属离子，并在天然水中缓冲它们。虽然人们认为金属离子浓度的降低会导致金属生物利用度的降低，但先前的工作表明，在腐殖酸存在的情况下，贻贝鳃对 Pb 的吸收能力大大增强。在本研究中，研究了更易溶解的有机物（富里酸和从河流中提取的 DOM）对贻贝及其鳃吸收 Pb 的影响。通过阳极溶出伏安法（ASV）测量这些有机物质对 Pb 的络合作用，证明在富里酸存在的情况下，贻贝鳃对 Pb 的吸收可以根据 ASV 不稳定 Pb 浓度成功预测。然而，在存在河流 DOM 的情况下，整个贻贝对 Pb 的吸收比根据 ASV 测量预测的要略高。根据 DOM 的物理化学性质，讨论了导致 DOM 对贻贝吸收 Pb 的不同影响的可能原因。
