While face masks have become a standard tool for respiratory protection, recent scientific evidence suggests they may also be a source of microscopic plastic exposure. A scoping review published in The Laryngoscope has examined how different types of masks and the way we wear them impact the amount and type of micro- and nano-plastics (MNPs) that end up in our upper respiratory tract.
A Shift from Fragments to Fibers
One of the most striking findings in the review is how masks change the physical nature of the plastic we inhale. In the general environment, most inhaled MNPs are fragments. However, in individuals wearing masks, fibers become the predominant shape found in nasal fluids.
Studies on mask-wearers found:
- Fibers predominated in the nasal samples of mask users, accounting for up to 92.1% of the particles in some groups.
- Commonly detected plastic types from masks included polystyrene, polyamide (nylon), and polyester.
Surgical vs. Cotton: Which Has a Higher Impact?
Research led by Zhang et al. (2024) specifically compared different masking scenarios among 113 students. The results showed a significant difference in MNP density based on the material:
- Surgical Masks: Associated with the highest density of MNPs in nasal lavage fluid.
- Cotton Masks: Associated with the lowest density of MNPs.
- Natural Exposure (No Mask): This group fell in the middle, showing more plastic than cotton mask wearers but less than those using surgical masks.
Potential Health Implications
While masks are vital for blocking pathogens and large pollutants, the inhalation of textile microfibers is not without risk. Experimental evidence suggests that certain synthetic microfibers, such as nylon and polyester, may inhibit the development of airway cells and organoids.
Furthermore, MNP exposure in the respiratory tract has been linked to oxidative stress and cellular inflammation, disruption of the respiratory microbiome, potentially increasing the abundance of bacteria associated with disease, and decreased tissue resistance, making the nasal lining more permeable.
Understanding the Context
It is important to note that MNPs were detected in all subjects studied, whether they wore masks or not. Plastic is a pervasive part of our modern air, particularly in urban areas. While surgical masks may contribute more fibers to the nasal cavity than cotton alternatives, researchers emphasize that the toxicity of these particles in human nasal tissue is still an emerging field of study and requires more standardized long-term investigation.
Author: Dr. KW Wong
Reference:
Dubois, P., Lechien, J. R., Al Barajraji, M., et al. (2025). Micro- and Nanoplastic Toxicity in Upper Respiratory Tract: A Scoping Review. The Laryngoscope.