Using a toxicokinetics approach to explain the effect of soil pH on cadmium bioavailability to Folsomia candida
Using a toxicokinetics approach to explain the effect of soil pH on cadmium bioavailability to Folsomia candida
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DOI：
10.1016/j.envpol.2013.05.024
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发表时间：
2013-09-01
影响因子：
8.9
通讯作者：
van Gestel, Cornelis A. M.
中科院分区：
文献类型：
--
作者：
Ardestani, Masoud M.;van Gestel, Cornelis A. M.
本研究的目的是通过将生物配体方法与毒性动力学建模联系起来，提高我们对土壤中金属生物可利用性的理解。我们测定了镉在假丝酵母菌（Folsomia candida, collemulbola）体内的生物积累动力学与土壤ph的关系。动物在5或20 μ g Cd g（-1）的LUFA 2.2土壤中暴露21天，然后在清洁土壤中消除21天。内部镉浓度使用一阶单室模型建模，将吸收速率常数（k(1)）与土壤、水或0.01 M CaCl2可提取浓度和孔隙水浓度相关。基于土壤总浓度，k(1)与土壤pH无关，而基于孔隙水浓度，k(1)随着pH的增加而强烈增加，这解释了H+离子的竞争减少，使镉在高pH的孔隙水中更具生物可利用性。这表明生物配体建模的原理适用于预测土壤无脊椎动物的镉积累动力学。(C) 2013 Elsevier Ltd.版权所有。
The aim of this study was to improve our understanding of metal bioavailability in soil by linking the biotic ligand approach with toxicokinetics modelling. We determined cadmium bioaccumulation kinetics in Folsomia candida (Collembola) as a function of soil pH. Animals were exposed for 21 days to LUFA 2.2 soil at 5 or 20 mu g Cd g(-1) dry soil followed by 21 days elimination in clean soil. Internal cadmium concentrations were modelled using a first-order one-compartment model, relating uptake rate constants (k(1)) to total soil, water or 0.01 M CaCl2 extractable and porewater concentrations. Based on total soil concentrations, k(1) was independent of soil pH while it strongly increased with increasing pH based on porewater concentrations explaining the reduced competition of H+ ions making cadmium more bioavailable in pore water at high pH. This shows that the principles of biotic ligand modelling are applicable to predict cadmium accumulation kinetics in soil-living invertebrates. (C) 2013 Elsevier Ltd. All rights reserved.