Universiteit van Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Science Park 904, 1098XH, Amsterdam, the Netherlands.
Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Schmallenberg, Germany.
Chemosphere. 2020 Dec;260:127608. doi: 10.1016/j.chemosphere.2020.127608. Epub 2020 Jul 11.
This study explores whether mechanistic understanding of plant uptake of perfluoroalkyl acids (PFAAs) derived from hydroponic experiments can be applied to soil systems. Lettuces (Lactuca sativa) were grown in outdoor lysimeters in soil spiked with 4 different concentrations of 13 PFAAs. PFAA concentrations were measured in soil, soil pore water, lettuce roots, and foliage. The PFAA uptake by the lettuce was compared with uptake measured in a hydroponic study. The foliage:pore water concentration ratios in the lysimeter were similar to the foliage:water concentration ratios from the hydroponic experiment. In contrast, the root:pore water concentration ratios in the lysimeter were 1-2 orders of magnitude lower than in the hydroponic study for PFAAs with 6 or more perfluorinated carbons. Hence, hydroponic studies can be expected to provide a good quantitative measure of PFAA transfer from soil to foliage if one accounts for soil:pore water partitioning and differences in transpiration rate. However, hydroponic studies will be of little value for estimating PFAA transfer from soil to roots because sorption to the root surface is greatly enhanced under hydroponic conditions.
本研究探讨了从水培实验中得出的关于植物对全氟烷基酸（PFAAs）吸收的机理理解是否可以应用于土壤系统。生菜（Lactuca sativa）在户外淋溶土柱中生长，土壤中添加了 4 种不同浓度的 13 种 PFAAs。测量了土壤、土壤孔隙水中、生菜根系和叶片中的 PFAA 浓度。将生菜对 PFAA 的吸收与水培研究中测量的吸收进行了比较。淋溶土柱中叶片与孔隙水的浓度比与水培实验中叶片与水的浓度比相似。相比之下，如果考虑到土壤与孔隙水的分配以及蒸腾速率的差异，那么对于具有 6 个或更多全氟化碳原子的 PFAAs，淋溶土柱中根系与孔隙水的浓度比在水培研究中要低 1-2 个数量级。因此，如果考虑到土壤与孔隙水的分配以及蒸腾速率的差异，水培研究可以很好地定量测量 PFAA 从土壤到叶片的转移。然而，由于在水培条件下对根表面的吸附大大增强，水培研究对于估计 PFAA 从土壤到根系的转移几乎没有价值。
