Medical Devices as an Emerging Source of Human Exposure to Microplastics and Nanoplastics: A Critical Review

Microplastics (MPs) and nanoplastics (NPs) are recognized as contaminants of relevance to human health. However, medical devices remain an insufficiently explored source of exposure. This review evaluates evidence on the release of MPs and NPs from polymer-based medical devices, with emphasis on particle-generation mechanisms, exposure pathways, and factors affecting release. The literature indicates that medical devices, including disposable masks and gloves, nasal irrigation devices, breastmilk storage bags, syringes, infusion bags, tubing and filters, extracorporeal circulation systems, ophthalmic surgical devices, orthodontic aligners and retainers, may release particles during manufacturing, storage, preparation, and clinical use, particularly under mechanical stress. Particle release is influenced by polymer type, device design, surface characteristics, temperature, contact time, fluid composition, storage conditions, mechanical abrasion, compression, bending, and repeated use. Of particular concern are medical applications involving direct access to the bloodstream, such as intravenous infusion and extracorporeal circulation, which may allow released particles to enter the circulation without passing through the gastrointestinal or respiratory tract. Thus, medical devices should be considered an emerging and distinct source of human exposure to MPs and NPs, while their potential risks must be interpreted in light of the available evidence and in the context of their essential clinical benefits.