Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies/College of the Environment & Ecology, Xiamen University, Xiamen 361102, China.
China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Selangor Darul Ehsan 43900, Malaysia.
Aquat Toxicol. 2023 May;258:106497. doi: 10.1016/j.aquatox.2023.106497. Epub 2023 Mar 15.
The continuous fragmentation of plastics and release of synthetic nanoplastics from products have been aggravating nanoplastic pollution in the marine ecosystem. The carrier role of nanoplastics may increase the bioavailability and toxicity effects of toxic metals, e.g., mercury (Hg), which is of growing concern. Here, the copepod Tigriopus japonicus was exposed to polystyrene nanoplastics (PS NPs) and Hg (alone or combined) at environmental realistic concentrations for three generations (F0-F2). Then, Hg accumulation, physiological endpoints, and transcriptome were analyzed. The results showed that the copepod's reproduction was significantly inhibited under PS NPs or Hg exposure. The presence of PS NPs caused significantly higher Hg accumulation, lower survival, and lower offspring production in copepods relative to Hg exposure, suggesting an increased threat to the copepod's survivorship and health. From the molecular perspective, combined PS NPs and Hg caused a graver effect on the DNA replication, cell cycle, and reproduction pathways relative to Hg exposure, linking to lower levels of survivorship and reproduction. Taken together, this study provides an early warning of nanoplastic pollution for the marine ecosystem not only because of their adverse effect per se but also their carrier role for increasing Hg bioaccumulation and toxicity in copepods.
塑料的持续碎片化和产品中合成纳米塑料的释放加剧了海洋生态系统中的纳米塑料污染。纳米塑料的载体作用可能会增加有毒金属（如汞，Hg）的生物利用度和毒性效应，这引起了越来越多的关注。在这里，哲水蚤（Tigriopus japonicus）在环境现实浓度下连续暴露于聚苯乙烯纳米塑料（PS NPs）和 Hg（单独或组合）三代（F0-F2）。然后，分析了 Hg 积累、生理终点和转录组。结果表明，PS NPs 或 Hg 暴露会显著抑制哲水蚤的繁殖。与 Hg 暴露相比，PS NPs 的存在导致哲水蚤体内 Hg 积累更高、存活率更低、后代产量更低，这表明对哲水蚤的生存和健康构成了更大的威胁。从分子角度来看，与 Hg 暴露相比，PS NPs 和 Hg 的联合作用对 DNA 复制、细胞周期和繁殖途径造成了更严重的影响，这与较低的存活率和繁殖力有关。综上所述，本研究不仅因为纳米塑料本身的不良影响，而且因为它们作为载体增加了 Hg 在哲水蚤体内的生物积累和毒性，为海洋生态系统中的纳米塑料污染提供了早期预警。
