Developmental toxicity of microplastics: Mechanisms of action, influencing factors and research progress

Microplastics are a ubiquitous and persistent class of pollutants that have been detected in water bodies, soil, the atmosphere, and living organisms worldwide; their developmental toxicity has become a central focus in the fields of environmental health and ecological risk assessment. This paper systematically reviews the primary mechanisms by which microplastics induce developmental toxicity, including physical damage, oxidative stress, gut microbiota dysbiosis, and early developmental damage. It further elucidates key regulatory factors such as particle size, concentration, chemical composition, duration of exposure, and species-specific sensitivity. Existing studies confirm that early life stages are highly susceptible to microplastic exposure, while nanoplastics, long-term exposure, and chemical additives can significantly potentiate their toxic effects. However, current research still has many shortcomings, such as a lack of data at realistic environmental concentrations, limited studies on synergistic and chronic toxicity, and a lack of direct evidence regarding human developmental systems. Future research should focus on real-world exposure scenarios, transgenerational effects, microbiome-mediated toxicity pathways, and highly sensitive analytical techniques to refine the risk assessment framework and provide support for the development of evidence-based environmental and health policies.