Historic contamination alters mercury sources and cycling in temperate estuaries relative to uncontaminated sites.
Historic contamination alters mercury sources and cycling in temperate estuaries relative to uncontaminated sites.
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历史污染改变了温带河口相对于未污染地点的汞来源和循环。
DOI：
10.1016/j.watres.2020.116684
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发表时间：
2021-02-15
期刊：
影响因子：
12.8
通讯作者：
Mason RP
中科院分区：
文献类型：
--
作者：
Seelen EA;Chen CY;Balcom PH;Buckman KL;Taylor VF;Mason RP
汞 (Hg) 是一种全球性持久污染物，可在自然系统中甲基化为毒性更强的形式（甲基汞；MeHg）。这两种形式都对人类和野生动物构成风险，并且接触通常始于水生环境。因此，量化水生浓度并确定来源途径对于了解生物暴露非常重要。在这项研究中，结合了美国东北部河口的数据，评估点源污染如何影响水柱总量和甲基汞的浓度和来源动态，重点关注沉积物与非沉积物源。采用偏最小二乘回归模型来确定一组与河口水柱甲基汞和总汞 (HgT) 最相关的变量。主要研究结果表明，受污染场地的 HgT 内部循环能力强于外部输入，这导致当地水柱中 HgT 和 MeHg 浓度升高。然而，未受污染的河口系统中的汞T源与当地流域有很强的联系，溶解的汞T与溶解的有机碳有关，颗粒汞T与流域土地利用和河口混合有关。几乎没有相关证据表明水体中的甲基汞浓度与此类系统中的沉积物有关，但与汞T不同的是，这些浓度也与流域没有明确的联系。相反，溶解水柱 HgT 的原位甲基化似乎主导了 MeHg 源途径。结果表明，在管理方面，汞点源污染场地应与非污染场地分开考虑，并且土地利用在沿海甲基汞动态中起着重要的间接作用。
Mercury (Hg) is a global and persistent pollutant which can be methylated to more toxic forms (methylmercury; MeHg) in natural systems. Both forms pose a risk to humans and wildlife, and exposure often begins in aquatic environments. Therefore, quantifying aquatic concentrations and identifying source pathways is important for understanding biotic exposure. In this study, data from estuaries in the Northeast United States were combined to evaluate how point source contamination impacts the concentration and source dynamics of water column total and MeHg with an emphasis on sediment versus non-sediment sources. Partial least squares regression models were implemented to identify a set of variables most related to water column MeHg and total Hg (HgT) across the estuaries. The main findings suggest that contaminated sites have strong internal recycling of HgT that dominates over external inputs, and this leads to elevated concentrations of HgT and MeHg in the local water columns. However, HgT sources in uncontaminated estuarine systems have a strong connection to the local watershed with dissolved HgT linked to dissolved organic carbon, and particulate HgT linked to watershed land use and estuarine mixing. There was little correlative evidence that water column MeHg concentrations were linked to sediment in such systems, but unlike HgT, the concentrations were also not clearly linked to the watershed. Instead, in situ methylation of dissolved water column HgT appeared to dominate the MeHg source pathway. The results suggest that Hg point-source contaminated sites should be considered independently from non-contaminated sites in terms of management, and that land use plays an important indirect role in coastal MeHg dynamics.
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影响因子：
9.8
作者：
Eckley, Chris S.;Branfireun, Brian
通讯作者：
Branfireun, Brian
影响因子：
11.4
作者：
Bergamaschi, Brian A.;Krabbenhoft, David P.;Aiken, George R.;Patino, Eduardo;Rumbold, Darren G.;Orem, William H.
通讯作者：
Orem, William H.
影响因子：
8.3
作者：
Driscoll, Charles T.;Chen, Celia Y.;Hammerschmidt, Chad R.;Mason, Robert P.;Gilmour, Cynthia C.;Sunderland, Elsie M.;Greenfield, Ben K.;Buckman, Kate L.;Lamborg, Carl H.
通讯作者：
Lamborg, Carl H.
影响因子：
3.2
作者：
Abdi, Herve;Williams, Lynne J.
通讯作者：
Williams, Lynne J.
影响因子：
12.8
作者：
Bravo, Andrea G.;Kothawala, Dolly N.;Amouroux, David
通讯作者：
Amouroux, David