College of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, PR China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, Hunan 411105, PR China.
College of Environment and Resources, Xiangtan University, Xiangtan, Hunan 411105, PR China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, Hunan 411105, PR China.
J Hazard Mater. 2024 Aug 5;474:134844. doi: 10.1016/j.jhazmat.2024.134844. Epub 2024 Jun 5.
With advances in plastic resource utilization technologies, polystyrene (PS) and sulfonated polystyrene (SPS) microplastics continue to be produced and retained in environmental media, potentially posing greater environmental risks. These plastics, due to their different physicochemical properties, may have different environmental impacts when compounded with other pollutants. The objective of this study was to investigate the combined toxic effects of PS and SPS on wheat using cadmium (Cd) as a background contaminant. The results demonstrated that Cd significantly impeded the normal growth of wheat by disrupting root development. Both PS and SPS exhibited hormesis at low concentrations and promoted wheat growth. Under combined toxicity, PS reduced oxidative stress and promoted the uptake of essential metal elements in wheat. Additionally, KEGG pathway analysis revealed that PS facilitated the repair of Cd-induced blockage of the TCA cycle and glutathione metabolism. However, high concentrations of SPS in combined toxicity not only enhanced oxidative stress and interfered with the uptake of essential metal elements, but also exacerbated the blocked TCA cycle and interfered with pyrimidine metabolism. These differences are related to the different stability (Zeta potential, Hydrodynamic particle size) of the two microplastics in the aquatic environment and their ability to carry heavy metal ions, especially Cd. The results of this study provide important insights into understanding the effects of microplastics on crops in the context of Cd contamination and their environmental and food safety implications.
随着塑料资源利用技术的进步，聚苯乙烯（PS）和磺化聚苯乙烯（SPS）微塑料不断被生产并滞留在环境介质中，可能带来更大的环境风险。这些塑料由于其不同的物理化学性质，与其他污染物复合时可能会产生不同的环境影响。本研究旨在以镉（Cd）为背景污染物，研究 PS 和 SPS 对小麦的联合毒性作用。结果表明，Cd 通过破坏根系发育显著阻碍了小麦的正常生长。PS 和 SPS 在低浓度下均表现出兴奋效应，促进了小麦的生长。在联合毒性下，PS 减轻了氧化应激并促进了小麦对必需金属元素的吸收。此外，KEGG 途径分析表明，PS 有助于修复 Cd 诱导的三羧酸循环和谷胱甘肽代谢受阻。然而，高浓度的 SPS 在联合毒性下不仅增强了氧化应激并干扰了必需金属元素的吸收，还加剧了受阻的三羧酸循环并干扰了嘧啶代谢。这些差异与两种微塑料在水环境中的不同稳定性（Zeta 电位、水动力粒径）及其携带重金属离子的能力有关，尤其是 Cd。本研究结果为了解微塑料在 Cd 污染背景下对作物的影响及其对环境和食品安全的影响提供了重要的见解。
