Plastic pollution may be reaching the heart through the bloodstream, and people suffering the most severe form of heart attack appear to carry the greatest burden. In a study published in the European Heart Journal, researchers detected microplastics and nanoplastics in the coronary blood of 84% of patients who had experienced a serious heart attack. The team also recorded smoking history and estimated each patient’s air pollution exposure on the day of testing and during the previous two years. Patients exposed to higher long-term levels of air pollution (PM2.5/particles measuring 2.5 μm or less in diameter) were more likely to carry microplastics. In those patients, the presence of plastic particles was associated with a higher risk of heart attack, stroke, and death from any cause.