Marine microplastics fuel long-range transport of radioactive nuclides: A review

Growing concerns over microplastics in marine environments have intensified research into their interactions with radioactive nuclides, given microplastics' chemical stability and extensive specific surface area, which render them highly effective carriers for radionuclide adsorption. This review adopts a systematic methodology, incorporating a comprehensive literature survey of peer-reviewed articles published in the past decade, and critically analyzes experimental data from both field and laboratory studies. This article first synthesizes current knowledge on the origins, distribution patterns, and physicochemical properties of both microplastics (e.g., PE, PVC, PN6, PET) and key radionuclides (e.g., U-232, Am-241, Np-237) in aquatic systems. It then provides a detailed examination of the adsorption behaviors and mechanisms, highlighting the influence of various parameters-such as pH, particle size, and environmental heterogeneity-on adsorption efficiency. Particular attention is paid to the fundamental chemical processes on microplastic surfaces, including electrostatic interactions and van der Waals forces, as well as the applicability of isotherm models (e.g., Langmuir, Freundlich) to accurately describe these interactions. Finally, the review delves into the transport and diffusion dynamics of microplastics, especially in coastal and open-ocean settings, discussing their implications for environmental monitoring and pollution mitigation strategies. By integrating these findings, the article underscores critical knowledge gaps and offers a foundation for advancing future research and environmental policies aimed at addressing the convergent challenges posed by microplastics and radioactive nuclides in marine ecosystems.