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- Breathing in Plastic: The Indoor Air Threat
Breathing in Plastic: The Indoor Air Threat
Sam Garcia
August 27, 2025
A recent study published in the journal PLOS One has revealed that adults may inhale approximately 68,000 microplastic particles daily from indoor air in homes and cars. The study, which was published on July 30, 2025, highlights that these estimates are considerably higher—about 100 times more—than previous calculations that focused on larger microplastic sizes.
The research, led by Nadiia Yakovenko and Jeroen Sonke from the University of Toulouse, France, investigated airborne microplastics in the 1 to 10 micrometer size range (PM10), which are small enough to penetrate deep into the lungs. Using Raman spectroscopy, the researchers analyzed air samples from both residential environments (apartments) and car cabins.
Key findings from the study include:
The median concentration of suspended microplastics in homes was 528 particles per cubic meter.
Car cabins showed significantly higher concentrations, with a median of 2,238 microplastic particles per cubic meter.
Over 90% of the microplastic particles detected in indoor air across both environments were small enough to be inhaled deep into the lungs.
The primary sources of these microplastics are believed to be the degradation of plastic-filled household items such as curtains, furniture, carpets, and textiles, as well as the plastic components within car interiors.
Given that people spend an average of 90% of their time indoors, including in homes and cars, the study emphasizes that the potential for significant exposure to microplastics through inhalation is much greater than previously understood. The researchers warn that the inhalation of these tiny plastic fragments could lead to oxidative stress, immune dysfunction, and damage to organs, and call for further research into the long-term health effects.
Detailed Breakdown of Findings:
High Inhalation Rate: Adults are estimated to inhale around 68,000 microplastic particles (1–10 µm in size) per day, and approximately 3,200 larger microplastic particles (10–300 µm) daily. Children are estimated to inhale 47,000 ± 28,000 MPs/day.
Prevalence in Indoor Air: The study highlights that indoor air contains significantly higher concentrations of microplastics than outdoor air. People in developed nations spend about 90% of their time indoors, including 5% in cars, increasing their potential exposure.
Particle Size and Health Risk: The research focused on microplastics in the 1–10 µm range, which are small enough to penetrate deep into lung tissue and potentially enter the bloodstream. Previous studies often focused on larger particles (20–200 µm) that are less likely to reach the lungs.
Dominant Particle Size: Over 90% of the microplastic particles found in indoor air across both homes and cars were smaller than 10 µm. The abundance of microplastics increases as particle size decreases, following a power law distribution.
Sources of Indoor Microplastics: These microscopic fragments originate from the degradation of everyday plastic-filled items such as carpets, curtains, furniture, textiles, and plastic components within car interiors.
Car Cabins as Major Sources: Car cabins showed a median concentration of 2,238 microplastic particles per cubic meter, which is four times higher than the median concentration of 528 particles per cubic meter found in residential environments. This is attributed to the enclosed nature and high plastic content of vehicle interiors, where heat, friction, and wear contribute to shedding particles.
Polymer Types: Polyethylene (PE) was the predominant polymer type in residential environments, while polyamide (PA) was more common in car cabins.
Methodology: The researchers utilized Raman spectroscopy, an advanced technique capable of detecting particles as small as 1 micrometer, to analyze air samples from apartments and cars in France.
Potential Health Impacts: Inhaled microplastics can cross cellular barriers, enter the bloodstream, and potentially cause systemic effects such as oxidative stress, immune responses, and damage to vital organs over time. They can also carry toxic additives like heavy metals and persistent organic pollutants, exacerbating their harmful effects. Long-term exposure is a concern for respiratory illnesses, hormone disruption, infertility, cardiovascular disease, and cancer.
Increased Levels with Human Activity: Higher human activity dramatically spiked microplastic levels, with one sample reaching 34,000 particles/m³ when two people were active in a room, compared to typical levels under 2,500.
Call for Further Research and Action: The study emphasizes the need for regular monitoring, a closer look at how these particles move and settle, and further research on the long-term health effects of microplastic inhalation. Experts suggest limiting exposure by avoiding single-use plastics, using cloth bags, switching to glass food containers, and reducing time in enclosed plastic-filled spaces.