Bronchiectasis, microplastics, and end-of-life
Diffuse lung disease and lung transplant network, occupational and environmental health section
A ubiquitous invasion: The rise of microplastics
About 6.3 billion tons of plastic waste were produced between 1950 and 2015.1 Their degradation into submillimeter fragments of 1 μm to 5 mm, is called microplastics (MP).2 MP are vectors of pollutants, pathologic microorganisms, and chemical additives used in their fabrication.3 Exposure to MP is unavoidable as they are bio-persistent and ubiquitous, even indoors.4 MP have been detected in the snow of large metropolitan areas and in remote locations.5 Humans are exposed to MP via oral ingestion and inhalation. A Brazilian study of human lung autopsy specimens revealed the presence of MP in 13 of 20 subjects.3
In vitro studies have suggested a causal role of polystyrene-MP in the development of chronic pulmonary disease through the formation of reactive oxygen species, inhibition of cell proliferation, and cellular morphology aberration.6 MP can cause local effects due to macrophage-induced inflammation, or alternatively, be transported distantly to the pleura and the systemic circulation.
In addition, MP may disrupt the endocrine pathway due to its estrogenic effects.7 Larger MPs of 8 to 10 µm, like nylon, have been associated with interstitial lung disease.8 Lung biopsies from workers exposed to airborne synthetic fibers (acrylic, polyester, and terylene) have revealed different degrees of inflammation, granulomas, and interstitial fibrosis.9 Factory workers exposed to polyvinyl chloride dust have increased risk of exertional dyspnea and decreased pulmonary function.10 Due to the pervasive nature of MP, it is essential to establish the global burden of airborne MP and to determine its role in lung health.
Bathmapriya Balakrishnan, MD
Member-at-Large
*Tyler Church, DO
Fellow-in-Training Member
*Disclaimer: The views expressed in this article are those of the author(s) and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government.
References
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3. Amato-Lourenço LF et al. Presence of airborne microplastics in human lung tissue. J Hazard Mater. 2021;416:126.
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5. Bergmann M et al. White and wonderful? Microplastics prevail in snow from the Alps to the Arctic. Sci Adv. 2019;5:eaax1157.
6. Dong CD et al. Polystyrene microplastic particles: In vitro pulmonary toxicity assessment. J Hazard Mater. 2020;385:121575.
7. Amato-Lourenço LF et al. An emerging class of air pollutants: Potential effects of microplastics to respiratory human health. Sci Total Environ. 2020;749:141676.
8. Kern DG et al. Flock worker’s lung: Chronic interstitial lung disease in the nylon flocking industry. Ann Intern Med. 1998;129[4]:261-72. Erratum in: Ann Intern Med. 1999;130[3]:246.
9. Pimentel JC et al. Respiratory disease caused by synthetic fibers: a new occupational disease. Thorax. 1975;30:204-19.
10. Soutar CA et al. Epidemiological study of respiratory disease in workers exposed to polyvinyl chloride dust. Thorax. 1980;35:644-52.
