Airborne microplastic particles may remain in the lungs for extended periods and influence immune system activity, according to new research investigating the biological effects of inhaled plastic pollutants.
Microplastics, tiny plastic fragments that have been detected everywhere from deep ocean ecosystems to human tissues, are increasingly viewed as a potential threat to both environmental and public health. Previous studies have linked exposure to these particles with inflammation, cellular damage, and disruptions to normal biological processes.
In the latest study, researchers from the Medical University of Vienna examined the effects of polyethylene terephthalate (PET) microplastics, one of the most widely used plastic materials worldwide. Using a mouse model, the team found that a single exposure was sufficient for the particles to remain detectable in lung tissue for at least 14 days.
The retained particles were associated with inflammation in the airways and increased levels of lymphocytes and eosinophils, immune cells that play a central role in allergic reactions and inflammatory processes.
Published in the Journal of Hazardous Materials Advances, the findings suggest that inhaled microplastics are not merely passive contaminants but may actively interact with the immune system and alter biological responses within the respiratory tract.
Researchers also observed that when PET microplastics were combined with ragweed pollen, a common airborne allergen, inflammatory reactions became even more pronounced. This finding raises the possibility that microplastic exposure could intensify allergic responses or modify the body’s reaction to environmental allergens.
According to the study authors, PET microplastics appear to function as biologically active particles capable of influencing airway inflammation and immune responses in ways that depend on both exposure levels and environmental conditions.
The research further highlights that measurable concentrations of airborne PET particles are already present in urban environments, meaning that people are routinely exposed to small quantities through everyday breathing. However, the scientists caution that the results were obtained in laboratory animals and should not be directly extrapolated to humans without additional investigation.
While further research is needed to determine the real-world implications for human health, the study adds to growing evidence that microplastics may have broader biological effects than previously understood. The authors argue that future risk assessments should include immune-related indicators and examine more closely the long-term consequences of chronic exposure to airborne plastic particles.