Overview

• The study estimates adults inhale about 68,000 microplastic particles per day in the 1–10 µm size range while indoors.
• Homes and car cabins showed median concentrations of 528 and 2,238 microplastics per cubic metre, respectively.
• More than 94% of detected particles were smaller than 10 µm, enabling them to penetrate deep into lung tissue.
• Researchers used Raman spectroscopy on 16 indoor air samples to directly measure fine microplastics, finding inhalation rates 100-fold higher than earlier estimates based on larger particles.
• Authors call for studies on long-term health impacts and for policymakers to consider stricter indoor air quality guidelines.