Influence of natural dissolved organic carbon on the bioavailability of mercury to a freshwater alga
Influence of natural dissolved organic carbon on the bioavailability of mercury to a freshwater alga
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DOI：
10.1016/j.envpol.2007.12.004
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发表时间：
2008-07-01
影响因子：
8.9
通讯作者：
Krabbenhoft, D. P.
中科院分区：
文献类型：
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作者：
Gorski, P. R.;Armstrong, D. E.;Krabbenhoft, D. P.
在含有不同浓度溶解有机碳（DOC）的野外采集淡水的生物测定中，评估了汞（Hg）对山羊硒的生物利用度。采用甲基汞（MeHg）和无机汞（II）的稳定同位素测定生物富集因子（BCF）。低doc湖水中MeHg的BCFs显著大于高doc湖水的BCFs。雨水中MeHg的BCF（最低DOC）是所有处理中最大的。雨水和湖水的Hg(II) BCFs也大于河水。此外，在美国和加拿大几个野外站点收集的淡水中，当DOC浓度为50 mg L-1时，汞（II）和甲基汞的BCFs较低。这些结果表明，高浓度的DOC抑制了汞的生物利用度，而低浓度的DOC可能为藻类吸收汞提供了最佳条件。然而，低DOC下BCFs的变异性表明，DOC组成或其他配体可能决定汞的位点特异性生物利用度。
Bioavailability of mercury (Hg) to Selenastrum capricornutum was assessed in bioassays containing field-collected freshwater of varying dissolved organic carbon (DOC) concentrations. Bioconcentration factor (BCF) was measured using stable isotopes of methylmercury (MeHg) and inorganic Hg(II). BCFs for MeHg in low-DOC lake water were significantly larger than those in mixtures of lake water and high-DOC river water. The BCF for MeHg in rainwater (lowest DOC) was the largest of any treatment. Rainwater and lake water also had larger BCFs for Hg(II) than river water. Moreover, in freshwater collected from several US and Canadian field sites, BCFs for Hg(II) and MeHg were low when DOC concentrations were >5 mg L-1. These results suggest high concentrations of DOC inhibit bioavailability, while low concentrations may provide optimal conditions for algal uptake of Hg. However, variability of BCFs at low DOC indicates that DOC composition or other ligands may determine site-specific bioavailability of Hg. Published by Elsevier Ltd.