Micro- and nanoplastic toxicity in humans: Exposure pathways, cellular effects, and mitigation strategies

Microplastics and nanoplastics (MNPs) are emerging environmental contaminants with increasing scientific evidence suggesting their potential risks to human health. The present review systematically explores the pathways through which these particles enter the human body, the cellular and molecular mechanisms of their toxicity, and current strategies to mitigate their effects. A structured literature review was conducted following PRISMA guidelines, focusing on studies published between 2019 and 2024 across major scientific databases. MNPs primarily enter the human system via ingestion, inhalation, and dermal exposure. Once internalized, they can accumulate in various organs and trigger oxidative stress, inflammation, apoptosis, and genotoxic effects. These toxic responses have been linked to chronic conditions such as metabolic disorders (e.g., diabetes, obesity), immune dysfunction, and neurodegenerative diseases. Furthermore, this review highlights emerging attenuation strategies, including advanced filtration technologies, bioremediation approaches, and bioactive compounds such as melatonin, astaxanthin, and probiotics. By identifying exposure pathways, toxic effects, and current research gaps, this review provides a comprehensive foundation for developing effective interventions to reduce MNP-related health risks and inform future toxicological studies.