Microplastics in marine environments: occurrence and degradation mechanisms

The aquatic ecosystem faces significant threats from microplastic (MP) contamination, a global environmental concern of growing magnitude. Plastic pollution presents a substantial challenge, underscored by empirical data. Nevertheless, efforts to mitigate microplastic pollution have faced significant challenges in achieving effective removal. Microplastics, owing to their small size, exhibit heightened absorption capacities within biological cells and possess a vast surface area. Their hydrophobic nature attracts co-contaminants, facilitating their infiltration into living organisms. With a persistent presence in the environment, microplastics traverse the food chain, ultimately reaching humans as the ultimate consumers. The destiny and mobility of microplastics in the environment remain uncertain. Understanding and regulating the environmental behavior of microplastics are crucial to devising effective solutions for microplastic pollution. While initial studies have explored the distribution of microplastics in aquatic settings, a comprehensive inquiry into their environmental behaviors and degradation mechanisms in marine ecosystems is urgently needed. This review provides a thorough overview of recent research on microplastics, encompassing their origins and dissemination in marine environments. It focuses on advancing our understanding of the degradation mechanisms of microplastics in marine settings.