Abstract TP089: Micro and Nano plastics in Cerebrovascular Health: A systematic Review of Current Evidence and Research Directions

Background: Microplastics (MPs) and nano plastics (NPs) are widespread environmental contaminants accumulating in humans. Emerging evidence connects their buildup to cardiovascular, cerebrovascular and neurological diseases. We synthesized recent human, animal, and mechanistic studies on MP/NP presence in biological tissues and implications for cerebrovascular health. Methods: We conducted a literature review following PRISMA rules of peer-reviewed studies published from 2021 to mid-2025, focusing on MP/NP exposure, tissue accumulation, cardiovascular outcomes, and mechanisms relevant to stroke pathophysiology. Selected studies addressed MP/NPs in human or animal models with measurable endpoints like tissue/plaque presence, blood detection, neurovascular impairment, oxidative stress, and inflammation. Results: Out of 47 reviewed studies, 10 reported relevant data for this review showing that humans ingest up to 5g of MPs weekly. A biomonitoring study detected MPs in 80% of healthy human blood samples (17 of 22), with a mean concentration of 1.6 μg/ml (Table). MPs were found in human carotid atheromas, correlating with adverse cardiovascular risk profiles. After a 34-month follow-up, non-fatal stroke was the most common adverse outcome in patients with MPs. Mechanistic studies in animal models show immune-mediated vascular occlusion and neurobehavioral impairments. A recent autopsy study found MPs/NPs in brain samples, with correlations to dementia cases, suggesting the brain may accumulate higher concentrations than other organs over time. Conclusion: Our findings collectively establish a biologically plausible link between MPs in vascular and brain tissues and the promotion of inflammation, oxidative stress and cerebrovascular pathology, that may contribute to stroke and cardiovascular disease risk. The presence of MPs in human blood and carotid plaques confirms their systemic absorption and deposition in arteries, linking them to higher rates of non-fatal stroke and suggesting their role in disease progression. The finding of MPs/NPs in human brains raises concerns about direct impacts on cerebrovascular and neurodegenerative health. The ability of these particles to cross the blood-brain barrier and trigger inflammatory responses provides a plausible mechanism for neurovascular dysfunction. Longitudinal human studies are needed to characterize dose-response relationships and effects on brain structure and function, as well as to establish exposure limits.