Beyond Polymer Identity: Biological and Health Implications of Polyvinyl Chloride Micro- and Nanoplastics

Polyvinyl chloride (PVC) micro- and nanoplastics (PVC-MNPs) represent heterogeneous exposures shaped by product formulation, ageing, environmental transformation and the release of associated chemicals. This review examines evidence on human exposure, tissue distribution and biological effects of PVC-MNPs, emphasising biological barriers and potential health implications. Exposure may occur through ingestion, inhalation, dermal contact and medical devices, while PVC has been detected in blood, placenta, reproductive and respiratory samples, and other human tissues. Experimental studies indicate that PVC-MNPs can impair epithelial homeostasis and induce oxidative stress, inflammatory responses, mitochondrial dysfunction and metabolic alterations. However, these effects vary with particle size, formulation, concentration, ageing, biological conditioning and experimental model. Environmental and biological transformations may modify particle properties, chemical release and microbial interactions, linking environmental contamination with food systems and human exposure within a One Health framework. Interpretation of the available evidence is limited by methodological heterogeneity, contamination risks, uncertain exposure doses, and limited comparability between experimental and clinical studies. Current evidence supports internal exposure and the biological plausibility of cellular and tissue injury but does not establish a causal relationship between PVC-MNP exposure and human disease. Future studies should integrate source-resolved exposure assessment, physiologically relevant models, appropriate leachate controls and standardised analytical methods.