In patients with carotid artery disease, the presence of microplastics and nanoplastics (MNPs) in the carotid plaque is associated with an increased risk of death or major cardiovascular events compared with patients in whom MNPs were not detected. This finding supports previous observational data that suggest an increased risk of cardiovascular disease in individuals exposed to plastics-related pollution.

In this prospective, multicentre, observational study, carotid plaque specimens were excised from 257 patients undergoing carotid endarterectomy and assessed for the presence of MNPs using pyrolysis–gas chromatography–mass spectrometry. Polyethylene was detected in the carotid plaques of 150 patients (mean level 21.7 ± 24.5 μg per mg of plaque); of these patients, 31 (12.1%) had quantifiable amounts of polyvinyl chloride (mean level 5.2 ± 2.4 μg per mg of plaque). In 10 randomly selected patients who had detectable levels of MNPs, visualization of the atheromatous plaque using transmission electron microscopy revealed evidence of particles within foamy macrophages. These particles had jagged edges and were <1 μm in size. Scanning electronic microscopy analysis also revealed the presence of chlorine in some particles. At 34 weeks, a primary end point event (a composite of myocardial infarction, stroke or all-cause death) occurred in 30 of 150 patients (20.0%) who had evidence of MNPs in the atheroma compared with only 8 of 107 patients (7.5%) who did not have evidence of MNPs (HR 4.5, 95% CI 2.0–10.3, P < 0.001).