A July 2025 study from researchers at the University of Toulouse found that people may be inhaling approximately 68,000 microplastic particles per day from indoor air alone — roughly 100 times higher than previous estimates that focused on larger particle sizes.
The study
Published in PLOS One, the research specifically measured suspended microplastics in the 1–10 micrometer range — small enough to penetrate deep into the lung. Median indoor residential concentrations were 528 microplastic particles per cubic meter of air. Ninety-four percent of detected particles were smaller than 10 micrometers. Polyethylene was the dominant polymer type. The authors conclude that "the health impacts of MP inhalation may be more substantial than we realize."
What it means
This isn't the first evidence that microplastics reach the lung. In 2022, researchers at the University of Hull published the first study to detect microplastics in lung tissue removed from live human patients, using μFTIR spectroscopy. Polypropylene, polyethylene, and polyethylene terephthalate were found across all lung regions.
Continuous inhalation exposure, particularly in indoor environments rich in synthetic fibers, raises concern about their contribution to respiratory disease.
A December 2025 review in EMBO Molecular Medicine linked microplastic inhalation to inflammation, oxidative stress, and epigenetic changes — and concluded that microplastics may worsen existing lung conditions including asthma, COPD, and pulmonary fibrosis.
The overall risk picture is still being built. In October 2025, the UK's Committee on the Medical Effects of Air Pollutants (COMEAP) concluded there is not yet enough data to quantify the health risk from typical environmental exposures. But it noted that historical studies of plastic and textile industry workers — exposed at higher concentrations — showed measurable lung function impairment and disease.
Where this lives in your home
The dominant indoor microplastic source is not outdoor air coming through windows — it is the synthetic materials inside the room itself. A 2024 systematic review in Journal of Exposure Science & Environmental Epidemiology found calculated indoor inhalation exposures consistently higher than outdoor, and identified infants as the highest-exposure group due to time spent near floor surfaces where fiber concentrations accumulate.
Polyester, acrylic, and nylon shed microfibers into air during ordinary movement — walking across a synthetic carpet, sitting on a polyester-upholstered sofa, or moving through a room where synthetic clothing is stored. An early study in Environmental Pollution (Dris et al., 2017) measured indoor microfiber concentrations at 10–40 times outdoor levels in the same location. The highest-shedding materials are synthetic pile textiles: fleece blankets, deep-pile acrylic rugs, and synthetic upholstery.
What to do
The material change most directly supported by the evidence is switching primary home textiles — bedding, rugs, upholstery — from synthetics to natural fibers: wool, linen, organic cotton. These shed organic fibers rather than polymer particles. If you're shopping right now, the product directory is filtered against these criteria, and the methodology behind those filters is public.
Cover image: Sasha P via Pexels (Pexels License) — source.
