Plasticopathology: Multi-Organ Damage and One Health Implications of Micro- and Nanoplastics

Microplastics (MPs) and nanoplastics (NPs) have emerged as pervasive environmental contaminants with increasing evidence of pathological consequences across biological systems. This study synthesizes current findings on histopathological alterations induced by MPs and NPs in multiple organ systems and animal species, highlighting their relevance to human health within a One Health framework. Analysis of recent experimental and field studies (2019-2025) revealed consistent lesions across the gastrointestinal, hepatobiliary, renal, reproductive, nervous, respiratory, cardiovascular, immune, and integumentary systems. Common pathological patterns include epithelial erosion, inflammatory infiltration, oxidative stress, cellular degeneration, and fibrosis, with severity often correlated to particle size, exposure route, and duration. The liver, kidney, and reproductive organs emerged as major targets of systemic toxicity, while translocation of particles across biological barriers underscores potential for multi-organ involvement. Evidence from animal models suggests trophic transfer of plastics through the food chain, posing direct and indirect risks to human health. Despite significant progress, knowledge gaps persist due to limited chronic exposure data, underrepresentation of veterinary and wildlife models, and lack of standardized exposure and detection methods. Hence, integration of omics technologies and exploring emerging areas such as transgenerational and epigenetic effects are essential for advancing mechanistic understanding. Overall, this review emphasizes the pathological continuum linking animal and human health impacts of plastic pollution and calls for coordinated global efforts-anchored in One Health principles to mitigate exposure, enhance surveillance, and inform evidence-based risk assessment and policy action.