de Santiago-Martín Ana, van Oort Folkert, González Concepción, Quintana José R, Lafuente Antonio L, Lamy Isabelle
Department of Soil Science, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain.
Environ Toxicol Chem. 2015 Jan;34(1):37-44. doi: 10.1002/etc.2772. Epub 2014 Nov 12.
The contribution of the nature instead of the total content of soil parameters relevant to metal bioavailability in lettuce was tested using a series of low-polluted Mediterranean agricultural calcareous soils offering natural gradients in the content and composition of carbonate, organic, and oxide fractions. Two datasets were compared by canonical ordination based on redundancy analysis: total concentrations (TC dataset) of main soil parameters (constituents, phases, or elements) involved in metal retention and bioavailability; and chemically defined reactive fractions of these parameters (RF dataset). The metal bioavailability patterns were satisfactorily explained only when the RF dataset was used, and the results showed that the proportion of crystalline Fe oxides, dissolved organic C, diethylene-triamine-pentaacetic acid (DTPA)-extractable Cu and Zn, and a labile organic pool accounted for 76% of the variance. In addition, 2 multipollution scenarios by metal spiking were tested that showed better relationships with the RF dataset than with the TC dataset (up to 17% more) and new reactive fractions involved. For Mediterranean calcareous soils, the use of reactive pools of soil parameters rather than their total contents improved the relationships between soil constituents and metal bioavailability. Such pool determinations should be systematically included in studies dealing with bioavailability or risk assessment.
利用一系列低污染的地中海农业石灰性土壤，这些土壤在碳酸盐、有机和氧化物组分的含量和组成方面具有自然梯度，以此测试了与生菜中金属生物有效性相关的土壤参数的性质而非总含量的贡献。通过基于冗余分析的典范排序比较了两个数据集：参与金属保留和生物有效性的主要土壤参数（成分、相或元素）的总浓度（TC数据集）；以及这些参数的化学定义反应性组分（RF数据集）。仅当使用RF数据集时，金属生物有效性模式才能得到令人满意的解释，结果表明结晶态铁氧化物、溶解有机碳、二乙烯三胺五乙酸（DTPA）可提取铜和锌以及不稳定有机库的比例占变异的76%。此外，通过金属加标测试了2种多污染情景，结果表明与RF数据集的关系比与TC数据集的关系更好（高出17%），且涉及新的反应性组分。对于地中海石灰性土壤，使用土壤参数的反应性库而非其总含量改善了土壤成分与金属生物有效性之间的关系。此类库的测定应系统地纳入涉及生物有效性或风险评估的研究中。
