Study Finds Indoor Air Contains Thousands of Microplastics

Thousands of microplastics so small they can penetrate the lungs have been found in indoor air environments, according to a recent study published in PLOS One.

The particles are likely the result of the degradation of plastic-filled objects such as carpets, curtains, furniture, textiles, and the plastic parts of car interiors.

The study found adults may inhale approximately 68,000 microplastic particles of 1 to 10 micrometers per day from indoor air. In comparison, a red blood cell is 6.2 to 8.2 micrometers, while E. coli bacteria may be 1 to 2 micrometers long. The study reported that this amount of microplastic particles is about 100 times more than expected.

Scientists have detected microplastics in human testes and the penis, human blood, lung and liver tissues, urine and feces, mother’s milk, and the placenta. A February study found nearly a spoon’s worth of microplastics in human brain tissue. A March 2024 study found that people with microplastics in their carotid artery tissues were twice as likely to have a heart attack, stroke, or die from any cause over the next three years than those who had none.

Nano plastics are the most worrisome type of plastic pollution for human health, according to experts. That’s because the minuscule particles can invade individual cells and tissues in major organs, potentially interrupting cellular processes and depositing endocrine-disrupting chemicals such as bisphenols, phthalates, flame retardants, perfluoroalkyl and polyfluoroalkyl substances (PFAS), and heavy metals.