Overview

• Researchers collected 16 air samples from residential environments and car cabins to quantify 1–10 µm microplastics using Raman spectroscopy.
• Median indoor concentrations reached 528 particles/m³ in homes and 2,238 particles/m³ in car cabins, with 94% of particles small enough to reach deep lung tissue.
• The team estimates adults inhale about 3,200 microplastics sized 10–300 µm and roughly 68,000 particles sized 1–10 µm each day.
• Exposure estimates for inhalable microplastics are up to 100 times higher than previous figures extrapolated from larger particles.
• Inhalable plastic fragments can penetrate deep into lungs and may trigger oxidative stress and immune disruption, raising concerns over long-term health risks.