Division of Agricultural Chemistry, Taiwan Agricultural Research Institute, Taichung City 41362, Taiwan.
Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan.
Environ Pollut. 2020 Jun;261:114189. doi: 10.1016/j.envpol.2020.114189. Epub 2020 Feb 14.
To understand the risk of two emerging contaminants, gallium (Ga) and indium (In) to humans via rice consumption, effects of soil properties and concentrations of spiked Ga/In on the accumulation of Ga and In in rice grains were investigated. A pot experiment was conducted, and paddy rice was grown in three soils with different pH values and Al availabilities (i.e., Pc, TWz and Cf), which were spiked with various Ga and In concentrations. The growth index and concentrations of Ga, In, and Al in plant tissues and soil pore water were measured. Results revealed that the concentrations of Ga and In in soil pore water increase with the spiking of Ga or In in all of the tested soils, but the biomass of roots and shoots does not significantly decrease. The accumulation of Ga in shoots and brown rice was significantly reduced in high available Al acidic soils (Pc soils), but this accumulation was significantly increased in low available Al acidic soils (TWz soils), which can be explained by the competitive uptake between Ga and Al by rice plants. The extent of competitive effects between In and Al was less than that between Ga and Al because of the lower solubility and translocation capability of In than those of Ga in soil-rice systems. However, significant differences in the concentrations of Ga and In in brown rice in neutral soils (Cf soils) among the Ga or In treatment were not observed. In addition, the iron plaque formed on the root surface can serve as a barrier to reduce the accumulation of Ga in rice plants. This study suggested that the risk of accumulation of Ga and In in rice grains should be of concern when paddy rice is grown in acidic Ga- or In-contaminated soils with low Al availability.
为了了解人类通过食用大米摄入两种新兴污染物镓（Ga）和铟（In）的风险，研究了土壤特性和添加 Ga/In 浓度对稻米中 Ga 和 In 积累的影响。进行了盆栽实验，在三种 pH 值和 Al 有效性不同的土壤（即 Pc、TWz 和 Cf）中种植水稻，并添加了不同浓度的 Ga 和 In。测量了植物组织和土壤孔隙水中的生长指数以及 Ga、In 和 Al 的浓度。结果表明，在所测试的所有土壤中，随着 Ga 或 In 的添加，土壤孔隙水中 Ga 和 In 的浓度增加，但根和茎的生物量没有明显减少。在高有效 Al 酸性土壤（Pc 土壤）中，Ga 在地上部和糙米中的积累显著减少，但在低有效 Al 酸性土壤（TWz 土壤）中，Ga 的积累显著增加，这可以用水稻植株对 Ga 和 Al 的竞争吸收来解释。由于 In 在土壤-水稻系统中的溶解度和迁移能力低于 Ga，因此 In 和 Al 之间的竞争效应程度小于 Ga 和 Al 之间的竞争效应程度。然而，在中性土壤（Cf 土壤）中，Ga 或 In 处理对糙米中 Ga 和 In 浓度没有显著差异。此外，在根表面形成的铁斑可以作为减少 Ga 在水稻植株中积累的屏障。本研究表明，当在酸性 Ga 或 In 污染且 Al 有效性低的土壤中种植水稻时，应关注稻米中 Ga 和 In 积累的风险。
