University of Bordeaux 1, UMR CNRS 5805 EPOC, Place du Docteur Peyneau, 33120 Arcachon, France; CNRS, EPOC, UMR 5805, F-33405 Talence, Cedex, France.
University of Bordeaux 1, UMR CNRS 5805 EPOC, Place du Docteur Peyneau, 33120 Arcachon, France; CNRS, EPOC, UMR 5805, F-33405 Talence, Cedex, France.
Chemosphere. 2014 Aug;108:214-24. doi: 10.1016/j.chemosphere.2014.01.042. Epub 2014 Mar 1.
The Riou-Mort watershed (southwest France) exhibits high metal contaminations (Cd and Zn) related to an important mining past. In this context, a remediation process has been implemented in 2007 to reduce the watershed contamination. The aim of this study was to assess the early effectiveness of the remediation process on the hydrosystem contamination state. A biomonitoring was realized over two years (2008-2010) with the filter-feeding bivalve Corbicula fluminea, exposed along a contamination gradient. Several biological parameters were monitored: (1) Cd and Zn bioaccumulation, (2) Metallothionein (MT) production as detoxification mechanism, (3) differential gene expression (cat, sod, gst, 12S, cox1, mt). The physicochemical data highlighted strong metal contamination persistence in the river water and failed to demonstrate a significant decrease of metal contamination during the 2-year monitoring. The bioaccumulation results confirmed the persistence of a water contamination despite remediation works, with maximum values measured downstream from the industrial site (Joany). The bioaccumulation increased in 2010, reaching 69.3±5.3 μg Cd g(-1) DW at Joany in July 2010, whereas it did not exceed 1.4±0.2 μg Cd g(-1) DW at the reference site throughout the biomonitoring. MT concentrations were closely related to the contamination gradient, especially at Joany, demonstrating their strong involvement in the detoxification processes. The mt gene induction was strongly correlated to the MT and metal concentrations. The gene inductions of cat, sod, gst and 12S were correlated to both the metal concentrations and the seasonal variations, especially temperatures. This suggests that environmental factors require serious consideration for the interpretation of bioaccumulation kinetics and thus for the assessment of the remediation effectiveness. Consequently, the whole results did not yet highlight strong beneficial effects of remediation work on the hydrosystem contamination state. First benefits of that process should be progressively felt, once the remediation achieved, and should grandly accelerate the decontamination process of the contaminated area.
里奥-莫尔流域（法国西南部）存在与重要采矿业历史相关的高金属污染（Cd 和 Zn）。在这种情况下，2007 年实施了一项修复工程，以减少流域的污染。本研究的目的是评估修复过程对水系统污染状况的早期有效性。使用滤食性双壳类贻贝 Corbicula fluminea 进行了为期两年（2008-2010 年）的生物监测，暴露在污染梯度中。监测了几个生物学参数：（1）Cd 和 Zn 的生物积累，（2）金属硫蛋白（MT）的产生作为解毒机制，（3）差异基因表达（cat、sod、gst、12S、cox1、mt）。理化数据突出表明，河水金属污染持续存在，并且在两年监测期间未能证明金属污染显著减少。生物积累结果证实，尽管进行了修复工程，但水的污染仍然存在，最大值是在工业场地下游（Joany）测量到的。2010 年生物积累增加，2010 年 7 月在 Joany 处达到 69.3±5.3μg Cd g(-1) DW，而在整个生物监测期间，在参考点处未超过 1.4±0.2μg Cd g(-1) DW。MT 浓度与污染梯度密切相关，特别是在 Joany，这表明它们在解毒过程中起着重要作用。mt 基因的诱导与 MT 和金属浓度密切相关。cat、sod、gst 和 12S 的基因诱导与金属浓度和季节性变化，特别是温度有关。这表明，环境因素需要认真考虑，以解释生物积累动力学，并因此评估修复效果。因此，整个结果尚未突出修复工程对水系统污染状况的显著有益影响。一旦修复完成，应该会逐渐感受到该过程的好处，并大大加速污染区域的脱污染进程。
