Tong Jing, He Siying, Huang Xiaoming, Li Xin, Nie Xiaodong, Li Zhengyang, Li Zhongwu, Xiong Weiping
School of Geographic Science, Hunan Normal University, Changsha 410081, PR China.
College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
J Contam Hydrol. 2025 Nov;275:104699. doi: 10.1016/j.jconhyd.2025.104699. Epub 2025 Aug 20.
Microplastics are ubiquitous in various environments with a wide distribution. When exposed to the natural environment, microplastics undergo photoaging under ultraviolet irradiation, accompanied by a series of physicochemical property changes such as bond breakage and oxygen addition. It is of great significance to understand the physical and chemical properties of photoaged microplastics and their potential environmental risks, but information is limited and lacking in summary to date. This paper summarizes the properties of photoaged microplastics, the factors influencing their aging, and the increased environmental risks following microplastics exposure to ultraviolet radiation in aquatic environments. Firstly, the apparent changes in photoaging behavior on microplastics' physical and chemical properties were outlined, including morphological characteristics, chemical structure, crystallinity, hydrophobicity, Zeta potential and leaching behavior. Then, the factors affecting the photoaging process were discussed comprehensively, including microplastic properties, environmental media, dissolved organic matter (DOM), clay minerals and inorganic anions. In addition, the environmental risks of photoaged microplastics as pollutant transport vectors and disruption of elemental cycles were analyzed. Notably, photoaged microplastics may enhance the induction of biological toxicity and human exposure risks. Finally, knowing the summarized above, some issues that deserve more attention for future research are forecasted. Since the UV-induced weathering of microplastics is a widespread phenomenon with implications for humans, society and the environment, this review could offer valuable insights for future research directions and environmental risk assessments of microplastics.
微塑料在各种环境中广泛存在且分布广泛。当暴露于自然环境中时，微塑料在紫外线照射下会发生光老化，伴随着一系列物理化学性质的变化，如化学键断裂和加氧反应。了解光老化微塑料的物理化学性质及其潜在的环境风险具有重要意义，但迄今为止相关信息有限且缺乏总结。本文综述了光老化微塑料的性质、影响其老化的因素，以及微塑料在水环境中暴露于紫外线辐射后增加的环境风险。首先，概述了微塑料光老化行为对其物理化学性质的明显影响，包括形态特征、化学结构、结晶度、疏水性、zeta电位和浸出行为。然后，全面讨论了影响光老化过程的因素，包括微塑料性质、环境介质、溶解有机物（DOM）、粘土矿物和无机阴离子。此外，分析了光老化微塑料作为污染物传输载体以及破坏元素循环的环境风险。值得注意的是，光老化微塑料可能会增强生物毒性诱导和人类暴露风险。最后，基于上述总结，预测了未来研究中一些值得更多关注的问题。由于微塑料的紫外线诱导风化是一种广泛存在的现象，对人类、社会和环境都有影响，本综述可为微塑料的未来研究方向和环境风险评估提供有价值的见解。
