Blood clots that form in the heart, arteries, and veins – called thrombi – are a major risk factor for heart attack, stroke, and respiratory problems. Evidence suggests that environmental factors contribute to thrombi formation. A recent study identified microplastics in 80 percent of surgically removed thrombi.

Researchers surgically removed thrombi from patients scheduled for arterial or venous thrombectomy in the brain, heart, or legs using plastic-free surgical implements and storage techniques. Using mass spectrometry, they assessed the thrombi for microplastic particle content and determined the particles' sizes, shapes, and numbers.

They found that 80 percent of the thrombi contained microplastics, including polyamide 66, polyvinyl chloride, and polyethylene. Higher concentrations of microplastics were associated with greater disease severity.

This study was small, but its findings suggest microplastics are present in human thrombi and further increase disease risk. Microplastics are pervasive environmental contaminants present in land, water, and air. They have also been detected throughout the human body, including the sputum, lungs, heart, liver, blood, endometrium, testis, amniotic fluid, and placenta. Recent research found that microplastics in human arterial plaques increase the risk for cardiovascular disease-related events nearly fivefold.