Microplastics as an emerging driver of osteoarthritis: a translational synthesis of environmental exposure, patho-mechanisms, and public health implications.

Background: Osteoarthritis (OA), a leading global cause of disability, has been increasingly associated with environmental microplastic (MP) exposure. MPs bioaccumulate in human tissues via the food chain and may disrupt joint homeostasis through inflammatory and oxidative pathways. However, their role in OA pathogenesis remains underexplored in translational contexts.

Methods: We conducted a synthesis of environmental microplastic contamination data from global aquatic ecosystems, integrated with molecular pathway analyses and epidemiological evidence. Microplastic sampling and polymer identification were performed using GPS mapping, stereomicroscopy, and Fourier-transform infrared (FTIR) spectroscopy. Public health implications were assessed through cost-effectiveness analyses of MP mitigation strategies.

Results: High MP exposure regions demonstrated elevated OA prevalence, with MPs identified in cartilage and skeletal tissues. Mechanistically, MPs activated NLRP3 inflammasomes, induced reactive oxygen species (ROS), and disrupted osteoblast/osteoclast balance. Epidemiological data revealed that populations in coastal and industrial regions exhibited up to 1.85-fold increased OA risk. Cost-benefit modeling indicated that MP reduction strategies, such as seafood safety regulations and advanced water filtration, could yield annual healthcare savings exceeding $50 billion globally.

Conclusions: Microplastics constitute an emerging and modifiable environmental risk factor for OA. Translational strategies targeting MP reduction may mitigate OA burden and offer substantial public health and economic benefits. This underscores the need for integrated environmental-health policies and further clinical investigation.