Microplastics in crustaceans imposing potential risk on human health: transferring, degradation, synergy, and metabolism

This review elucidates the biotransformation mechanisms and ecological health risks of micro/nanoplastics (MNPs) in crustaceans, aiming to address knowledge gaps in their biological degradation processes and associated hazards. It highlights MNPs presence in crustaceans, emphasizing factors influencing their toxicity, including metabolic pathways post-ingestion and subsequent transfer to humans through the food chain. Direct and indirect toxic effects on crustaceans and humans are summarized, alongside potential implications of MNP metabolism. The research reveals that combined toxicity of MNPs and co-existing environmental contaminants may elevate human health risks via crustacean consumption. Notably, it presents the first evidence of microplastics (MPs) being converted to nanoplastics (NPs) during the digestive process in Antarctic krill, raising concerns about the heightened hazards of MNPs. These findings underscore the role of crustaceans as valuable ecotoxicological sentinels for MNP risk assessment and offer novel insights into the mechanisms underlying composite toxicity along the food chain. The article also identifies critical research gaps, such as the interactions between gut microbiota and MNPs, and the modulatory roles of polysaccharides and proteins in MNP metabolism. By integrating metabolic pathways, ecological impacts, and human health risks, this work provides a comprehensive framework for understanding MNPs bioaccumulation dynamics and their systemic health consequences.