Washington State University, School of the Environment, P.O. Box 642812, Pullman, WA, 99164, USA.
Washington State University, School of the Environment, P.O. Box 642812, Pullman, WA, 99164, USA.
Environ Pollut. 2018 Jul;238:348-358. doi: 10.1016/j.envpol.2018.03.042. Epub 2018 Mar 22.
The upper Columbia River and associated valley systems are highly contaminated with metal wastes from nearby smelting operations in Trail, British Columbia, Canada (Teck smelter), and to a lesser extent, Northport, Washington, USA (Le Roi smelter). Previous studies have investigated depositional patterns of airborne emissions from these smelters, and documented the Teck smelter as the primary metal contamination source. However, there is limited research directed at whether these contaminants are bioavailable to aquatic organisms. This study investigates whether smelter derived contaminants are bioavailable to freshwater zooplankton. Trace metal (Zn, Cd, As, Sb, Pb and Hg) concentrations and Pb isotope compositions of zooplankton and sediment were measured in lakes ranging from 17 to 144 km downwind of the Teck smelter. Pb isotopic compositions of historic ores used by both smelters are uniquely less radiogenic than local geologic formations, so when zooplankton assimilate substantial amounts of smelter derived metals their compositions deviate from local baseline compositions toward ore compositions. Sediment metal concentrations and Pb isotope compositions in sediment follow significant (p < 0.001) negative exponential and sigmoidal patterns, respectively, as distance from the Teck smelting operation increases. Zooplankton As, Cd, and Sb contents were related to distance from the Teck smelter (p < 0.05), and zooplankton Pb isotope compositions suggest As, Cd, Sb and Pb from historic and current smelter emissions are biologically available to zooplankton. Zooplankton from lakes within 86 km of the Teck facility display isotopic evidence that legacy ore pollution is biologically available for assimilation. However, without water column data our study is unable to determine if legacy contaminants are remobilized from lake sediments, or erosional pathways from the watershed.
哥伦比亚河上游流域及其相关的河谷系统受到加拿大不列颠哥伦比亚省 Trail 附近冶炼厂（Teck 冶炼厂）和美国华盛顿州 Northport 附近冶炼厂（Le Roi 冶炼厂）排放的金属废物的高度污染。先前的研究调查了这些冶炼厂排放的空气传播污染物的沉积模式，并记录了 Teck 冶炼厂是主要的金属污染来源。然而，针对这些污染物是否对水生生物具有生物可利用性的研究有限。本研究调查了冶炼厂衍生的污染物是否对淡水浮游动物具有生物可利用性。在距离 Teck 冶炼厂 17 至 144 公里的湖泊中测量了浮游动物和沉积物中的痕量金属（Zn、Cd、As、Sb、Pb 和 Hg）浓度和 Pb 同位素组成。两个冶炼厂使用的历史矿石的 Pb 同位素组成明显比当地地质构造放射性低，因此当浮游动物大量吸收来自冶炼厂的金属时，它们的组成会偏离当地基线组成，向矿石组成靠拢。随着距离 Teck 冶炼厂的增加，沉积物中的金属浓度和 Pb 同位素组成分别遵循显著（p < 0.001）的负指数和 S 型模式。浮游动物 As、Cd 和 Sb 含量与距离 Teck 冶炼厂有关（p < 0.05），浮游动物 Pb 同位素组成表明，来自历史和当前冶炼厂排放的 As、Cd、Sb 和 Pb 对浮游动物具有生物可利用性。距离 Teck 设施 86 公里内的湖泊中的浮游动物显示出同位素证据，表明遗留的矿石污染对生物可同化。然而，由于缺乏水柱数据，我们的研究无法确定是否从湖底沉积物或流域侵蚀途径重新释放了遗留污染物。
