Xie Dongmei, Gai Yingbao, Zhang Yunlei, Zhang Jingjing, Xin Ye-Hong, Xu Jing, Wang Minghua
Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies/College of the Environment & Ecology, Xiamen University, Xiamen 361102, China.
Environ Sci Technol. 2025 Jan 14;59(1):234-244. doi: 10.1021/acs.est.4c10189. Epub 2024 Dec 31.
Aged plastics possess diverse interactive properties with metals compared to pristine ones. However, the role of aging for nanoplastics (NPs) in being a carrier of mercury (Hg), a common marine environmental pollutant, and their combined effects remain unclear. This study investigated the carrier effect of ultraviolet-aged NPs on Hg and the ensuing toxicity in a marine copepod under a multigenerational scenario. Aged NPs revealed a better carrier role in Hg bioaccumulation than pristine ones, which was increased by 1.61, 1.52, and 1.54 times in F0, F1, and F2, respectively, probably attributed to increased levels of O-containing functional groups and better adsorption for Hg. Consequently, relative to Hg alone, Hg combined with aged NPs (rather than pristine ones) significantly compromised the copepod's fitness, e.g., the survival rate decreasing by 74.2 and 62.1% in F1 and F2, respectively. This is possibly linked to the most pronounced transcriptomic response under Hg combined with aged NPs, including disturbed cuticle formation, activated antioxidants, and down-regulation of reproductive genes. Overall, our findings emphasize the non-negligible risk of aged NPs as carriers of toxic metals and provide a better understanding about the long-term effects of coexisting NPs and metal pollution on organisms in real marine environments.
与原始塑料相比，老化塑料与金属具有多种相互作用特性。然而，老化对纳米塑料（NPs）作为汞（Hg）（一种常见的海洋环境污染物）载体的作用及其综合影响仍不清楚。本研究在多代实验条件下，研究了紫外线老化的纳米塑料对汞的载体效应以及随后对海洋桡足类动物的毒性。老化的纳米塑料在汞生物累积方面比原始纳米塑料表现出更好的载体作用，在F0、F1和F2代中分别增加了1.61、1.52和1.54倍，这可能归因于含氧化官能团水平的增加以及对汞的更好吸附。因此，相对于单独的汞，汞与老化的纳米塑料（而非原始纳米塑料）结合显著损害了桡足类动物的健康，例如，F1和F2代的存活率分别下降了74.2%和62.1%。这可能与汞与老化纳米塑料结合时最明显的转录组反应有关，包括角质层形成紊乱、抗氧化剂激活以及生殖基因下调。总体而言，我们的研究结果强调了老化纳米塑料作为有毒金属载体的不可忽视的风险，并为更好地理解纳米塑料和金属污染在真实海洋环境中共存对生物的长期影响提供了依据。
