MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China; Tianjin Engineering Research Center of Environmental Diagnosis and Contamination Remediation, Tianjin 300350, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, PR China; Tianjin Engineering Research Center of Environmental Diagnosis and Contamination Remediation, Tianjin 300350, China.
Sci Total Environ. 2024 Nov 15;951:175592. doi: 10.1016/j.scitotenv.2024.175592. Epub 2024 Aug 17.
N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), a widely used antioxidant in rubber products, and its corresponding ozone photolysis product N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q), have raised public concerns due to their environmental toxicity. However, there is an existing knowledge gap on the toxicity of 6PPD and 6PPD-Q to aquatic plants. A model aquatic plant, Chlorella vulgaris (C. vulgaris), was subjected to 6PPD and 6PPD-Q at concentrations of 50, 100, 200, and 400 μg/L to investigate their effects on plant growth, photosynthetic, antioxidant system, and metabolic behavior. The results showed that 6PPD-Q enhanced the photosynthetic efficiency of C. vulgaris, promoting growth of C. vulgaris at low concentrations (50, 100, and 200 μg/L) while inhibiting growth at high concentration (400 μg/L). 6PPD-Q induced more oxidative stress than 6PPD, disrupting cell permeability and mitochondrial membrane potential stability. C. vulgaris responded to contaminant-induced oxidative stress by altering antioxidant enzyme activities and active substance levels. Metabolomics further identified fatty acids as the most significantly altered metabolites following exposure to both contaminants. In conclusion, this study compares the toxicity of 6PPD and 6PPD-Q to C. vulgaris, with 6PPD-Q demonstrating higher toxicity. This study provides valuable insight into the risk assessment of tire wear particles (TWPs) derived chemicals in aquatic habitats and plants.
N-(1,3-二甲基丁基)-N'-苯基-对苯二胺（6PPD）是一种广泛应用于橡胶制品的抗氧化剂，其相应的臭氧光解产物 N-(1,3-二甲基丁基)-N'-苯基-对苯二胺-醌（6PPD-Q）因其环境毒性而引起公众关注。然而，关于 6PPD 和 6PPD-Q 对水生植物的毒性，目前还存在知识空白。本研究选用模式水生植物小球藻（Chlorella vulgaris，C. vulgaris），采用浓度为 50、100、200 和 400μg/L 的 6PPD 和 6PPD-Q 处理，研究其对植物生长、光合作用、抗氧化系统和代谢行为的影响。结果表明，6PPD-Q 提高了 C. vulgaris 的光合作用效率，在低浓度（50、100 和 200μg/L）下促进了 C. vulgaris 的生长，而在高浓度（400μg/L）下抑制了生长。6PPD-Q 诱导的氧化应激比 6PPD 更严重，破坏了细胞通透性和线粒体膜电位稳定性。C. vulgaris 通过改变抗氧化酶活性和活性物质水平来应对污染物诱导的氧化应激。代谢组学进一步确定脂肪酸是两种污染物暴露后变化最显著的代谢物。综上所述，本研究比较了 6PPD 和 6PPD-Q 对 C. vulgaris 的毒性，结果表明 6PPD-Q 的毒性更高。本研究为轮胎磨损颗粒（Tire Wear Particles，TWPs）衍生化学物质在水生栖息地和植物中的风险评估提供了有价值的信息。
