Microplastics — plastic particles <5mm — and nanoplastics (<1μm) have been detected in virtually every ecosystem on Earth, including in human blood, lung tissue, placenta, breast milk, fetal meconium, and most recently in atherosclerotic plaques in a landmark 2024 NEJM study. The science has moved from "microplastics exist in the environment" to "microplastics are inside human bodies" — with the clinical question now being: at current body burden levels, do they cause measurable harm?
What Has Been Found and Where
Blood: Ragusa et al. (2022): detected polyethylene terephthalate (PET), polystyrene, and polypropylene in 77% of blood samples from 22 healthy adults. Concentrations: mean 1.6 μg/mL. Placenta: microplastics detected in placentas from normal pregnancies — with higher concentrations associated with markers of placental inflammation. Lungs: microplastics detected in all 11 lung tissue samples analyzed in a 2022 Environment International study — including in the upper, middle, and lower lobes. Atherosclerotic plaques (NEJM, March 2024): this was the breakthrough finding. Microplastics and nanoplastics were detected in 58% of carotid atherosclerotic plaques (n=257). Patients with plastics in plaques had a 4.5× higher risk of MI, stroke, or death at 34-month follow-up. This is the first evidence linking microplastics to a hard clinical cardiovascular outcome — though causation is not established from this observational design.
Proposed Mechanisms and Exposure Reduction
Proposed toxicity mechanisms: physical irritation from particle ingestion, leaching of plasticizers (phthalates, bisphenols — known endocrine disruptors), persistent organic pollutants adsorbed to plastic surfaces (PCBs, pesticides), and direct inflammatory pathway activation. Bisphenol A (BPA) and phthalate evidence: these chemical components of plastics have the clearest evidence of endocrine disruption — both are associated with reproductive dysfunction, thyroid disruption, and metabolic syndrome in observational data. Practical exposure reduction: reduce single-use plastic food contact, don't heat food in plastic containers (heat dramatically increases leaching), reduce processed foods in plastic packaging, use water filters certified for microplastic removal, avoid PVC (polyvinyl chloride) products. For clinical settings concerned about patient chemical exposures, our medical gloves section includes nitrile and non-latex options minimizing phthalate exposure in clinical settings.
