Metal mixture effects in soils contaminated with Cu, Ni and Zn

土壤中个别微量金属的毒性已研究多年。然而，痕量金属很少单独存在于土壤中，因此需要了解金属混合物的毒性，以确定环境中金属的安全水平。研究将与三个国际金属协会（国际铜协会、国际锌协会和镍生产者环境研究协会）、一家专门从事环境建模的私营公司（HydroQual）和一个由William Hendershot领导的大学研究小组（麦吉尔大学）合作进行，这些协会的部分资金来自加拿大金属采矿和精炼业。金属环境研究协会越来越担心土壤中铜、镍和锌的毒性会被高估，导致对这些金属的使用更严格的限制。在这种情况下，如果在土壤中发现一种以上的金属浓度升高，毒性可能会增加，这可能会导致对金属向环境中的释放施加更严格的限制。对这些金属的使用实行更严格的管制将导致加拿大采矿和金属生产公司的出口减少，这将对加拿大经济产生负面影响。这些实验将确定金属如何在土壤和植物根系表面相互作用。实验将以这样的方式进行，即数据可用于校准陆地生物配体模型，该模型将基于1）土壤溶液中的金属与吸附在土壤颗粒上的金属之间的相互作用和2）植物根部从土壤溶液中吸附的金属量来预测金属混合物的毒性。我们的合作者之一HydroQual正在开发的模型将为金属行业提供一种工具，用于评估金属混合物在不同金属释放情况下的影响。

The toxicity of individual trace metals in soils has been studied for many years. However, trace metals are rarely found alone in soils and so the toxicity of metal mixtures needs to be understood in order to determine safe levels of metals in the environment. Research will be carried out collaboratively with three international metal associations, funded in part by the Canadian metal mining and refining industry, (International Copper Association, International Zinc Association and the Nickel Producers Environmental Research Association), a private firm that specializes in environmental modeling (HydroQual) and a university research group led by William Hendershot (McGill University). Metal environmental research associations are becoming increasingly concerned that the toxicity of Cu, Ni and Zn in soils will be over-estimated leading to greater restrictions on the use of these metals. In this context, the possible augmentation in toxicity when more than one metal is found in elevated concentrations in soils could lead to much more stringent limits being put on the release of metals into the environment. Tighter regulations on the use of these metals would lead to decreased exports by Canadian mining and metal producing companies, which would have a negative impact on the Canadian economy. The experiments will determine how metals interact in soil and on the surfaces of plant roots. The experiments will be conducted in such a way that the data can be used to calibrate a terrestrial biotic ligand model that will predict toxicity of metal mixtures based on 1) the interactions between metals in the soil solution and adsorbed on soil particles and 2) the amounts of metals that are sorbed by the plant root from the soil solution. The model that is being developed by HydroQual, one of our collaborators, will provide the metal industry a tool to evaluate the effects of metal mixtures under different metal release scenarios.