Micro- and Nanoplastic-Induced Respiratory Disease and Dysfunction: A Scoping Review

Background: Human bioaccumulation of micro- and nanoplastics (MNPs) is increasingly being recognised in the aetiology and pathophysiology of human disease. This systematic scoping review aims to provide a comprehensive investigation of studies examining the presence and effects of MNPs on the human pulmonary system. Methods: A scoping review was conducted in line with JBI guidelines. Five databases (PubMed, SCOPUS, CINAHL, Web of Science and EMBASE) were systematically searched. Results: Sixty-eight articles were identified, with fifteen reporting the presence of MNPs in human respiratory tissues and fluids. The data reported in the remaining toxicology-focused studies suggest that MNPs induce widespread cellular dysfunction in pulmonary-related human cell lines. Exposure to MNPs was associated with significant cytotoxicity, genotoxicity and altered metabolic activity, including mitochondrial damage, increased reactive oxygen species and reduced membrane potential. Functionalised and smaller particles had more pronounced effects. Conclusions: The reported presence of MNPs, coupled with their biological toxicity, represents a growing global health concern. Evidence suggests MNPs may contribute to the rising burden of pulmonary disease worldwide, including cancer, COPD, interstitial lung disease and ARDS. Urgent international research is needed to characterise exposure pathways, develop standardised detection methods and understand the long-term health implications of MNP inhalation across the lifespan.