Irstea, UR HBAN Hydrosystems and Bioprocesses, 1 rue Pierre-Gilles de Gennes, F-92761 Antony Cedex, France; FIRE FR-3020, 4 place Jussieu, 75005 Paris, France.
Irstea, UR HBAN Hydrosystems and Bioprocesses, 1 rue Pierre-Gilles de Gennes, F-92761 Antony Cedex, France; FIRE FR-3020, 4 place Jussieu, 75005 Paris, France.
Water Res. 2016 May 15;95:330-9. doi: 10.1016/j.watres.2016.03.023. Epub 2016 Mar 14.
Kinetic models have become established tools for describing trace metal bioaccumulation in aquatic organisms and offer a promising approach for linking water contamination to trace metal bioaccumulation in biota. Nevertheless, models are based on laboratory-derived kinetic parameters, and the question of their relevance to predict trace metal bioaccumulation in the field is poorly addressed. In the present study, we propose to assess the capacity of kinetic models to predict trace metal bioaccumulation in gammarids in the field at a wide spatial scale. The field validation consisted of measuring dissolved Cd, Cu, Ni and Pb concentrations in the water column at 141 sites in France, running the models with laboratory-derived kinetic parameters, and comparing model predictions and measurements of trace metal concentrations in gammarids caged for 7 days to the same sites. We observed that gammarids poorly accumulated Cu showing the limited relevance of that species to monitor Cu contamination. Therefore, Cu was not considered for model predictions. In contrast, gammarids significantly accumulated Pb, Cd, and Ni over a wide range of exposure concentrations. These results highlight the relevance of using gammarids for active biomonitoring to detect spatial trends of bioavailable Pb, Cd, and Ni contamination in freshwaters. The best agreements between model predictions and field measurements were observed for Cd with 71% of good estimations (i.e. field measurements were predicted within a factor of two), which highlighted the potential for kinetic models to link Cd contamination to bioaccumulation in the field. The poorest agreements were observed for Ni and Pb (39% and 48% of good estimations, respectively). However, models developed for Ni, Pb, and to a lesser extent for Cd, globally underestimated bioaccumulation in caged gammarids. These results showed that the link between trace metal concentration in water and in biota remains complex, and underlined the limits of these models, in their present form, to assess trace metal bioavailability in the field. We suggest that to improve model predictions, kinetic models need to be complemented, particularly by further assessing the influence of abiotic factors on trace metal uptake, and the relative contribution of the trophic route in the contamination of gammarids.
动力学模型已成为描述水生生物中痕量金属生物积累的常用工具，为将水污染与生物体内痕量金属生物积累联系起来提供了一种有前途的方法。然而，模型是基于实验室得出的动力学参数，而将其应用于预测野外痕量金属生物积累的问题尚未得到很好的解决。在本研究中，我们提出评估动力学模型在广泛的空间尺度上预测野外大型蚤中痕量金属生物积累的能力。野外验证包括在法国 141 个地点测量水柱中溶解态 Cd、Cu、Ni 和 Pb 的浓度，用实验室得出的动力学参数运行模型，并将模型预测值与在同一地点放置 7 天的大型蚤中痕量金属浓度的测量值进行比较。我们发现，大型蚤对 Cu 的积累能力较差，表明该物种对监测 Cu 污染的相关性有限。因此，Cu 未被用于模型预测。相比之下，大型蚤在广泛的暴露浓度范围内显著积累 Pb、Cd 和 Ni。这些结果突出表明，使用大型蚤进行主动生物监测以检测淡水生物可利用性 Pb、Cd 和 Ni 污染的空间趋势具有重要意义。模型预测值与野外测量值之间的最佳一致性是在 Cd 上观察到的，有 71%的良好估计值（即野外测量值在两倍的范围内预测），这突出了动力学模型将 Cd 污染与野外生物积累联系起来的潜力。Ni 和 Pb 的一致性最差（分别为 39%和 48%的良好估计值）。然而，为 Ni、Pb 开发的模型，以及在较小程度上为 Cd 开发的模型，总体上低估了笼养大型蚤中的生物积累。这些结果表明，水中痕量金属浓度与生物体内痕量金属浓度之间的联系仍然很复杂，并强调了这些模型在其现有形式下评估野外痕量金属生物可利用性的局限性。我们建议，为了提高模型预测值，动力学模型需要得到补充，特别是需要进一步评估非生物因素对痕量金属吸收的影响，以及营养途径在大型蚤污染中的相对贡献。
