Researchers have discovered tiny plastic particles lodged in human lungs, with higher concentrations found in individuals diagnosed with lung cancer. The study’s findings have been published in the Journal of Clinical Medicine.
According to new research, microplastics are more frequently detected—and in greater quantities—in the lungs of people diagnosed with lung cancer. These results provide further evidence that these minute plastic particles enter the human body through the air we breathe and raise serious questions about a potential link to lung disease.
The study was led by Ilias Dimeas of the University College Dublin School of Medicine and the University of Thessaly in Larissa, Greece.
“Microplastics have become an integral part of our environment, yet we still know very little about what happens after they enter the human body,” said lead researcher Ilias Dimeas. “We do not yet know the baseline level of microplastics in the lungs, how much this varies from person to person, or whether they contribute to the development of disease. If we are inhaling these particles daily, we need to understand where they ultimately end up and whether they might be linked to illness.”
The study involved 100 individuals undergoing bronchoscopy at the University Hospital of Larissa in Thessaly, Greece. Bronchoscopy is a procedure in which doctors insert a thin, flexible endoscope into the lungs to investigate symptoms and collect samples directly.
As part of the procedure, each patient provided a lung fluid sample, obtained by washing a section of the lung with saline solution to collect cells and other substances. For half of the patients, researchers also collected a small tissue sample directly from the lung itself. Each sample underwent detailed analysis for the presence of microplastics, and a subset of samples was further tested to precisely identify the specific types of plastic present. Of the 100 patients examined, 50 were ultimately diagnosed with lung cancer, while the remaining 50 were not.
Researchers identified a total of 232 individual microplastic particles across all collected samples. Microplastics were detected in at least one sample—whether lung lavage fluid, tissue, or both—in 70 percent of all patients.
However, a distinct pattern emerged when researchers combined the results from each patient’s lung lavage and tissue samples. Patients with lung cancer were more likely to have microplastics detected, and they exhibited a higher total load of microplastics in their bodies compared to patients without cancer.
Looking specifically at the lung lavage samples, microplastics were found in 66 percent of lung cancer patients, compared to 46 percent of patients without cancer. Patients with cancer also showed a higher total microplastic content in these samples.
One particularly interesting detail came to light when researchers compared the lung lavage samples with the tissue samples from each patient. Patients who had higher levels of microplastics in their lung lavage fluid tended to have lower levels in the corresponding tissue sample, and vice versa.
Lung lavage samples collect material from the airways and air spaces of the lungs, whereas tissue samples collect material located within the lung tissue itself. This pattern suggests that microplastics are unevenly distributed throughout the lungs.
Regarding the specific types of plastic identified by the researchers, polypropylene and polyethylene were the most frequently encountered. Both materials are commonplace and widely used in packaging, textiles, household goods, and countless consumer products.
“Our findings show that inhaled microplastics may be found in human lungs more frequently than many might imagine,” said Dimeas. “This adds to the growing body of evidence that reducing environmental plastic pollution could benefit not only ecosystems but also human health.”
The study does not explain why higher levels of microplastics were observed in cancer patients, and Dimeas points to two competing explanations that are still being considered.
“Microplastics could contribute to inflammation or other biological processes that might lead to diseases like cancer, but it is also possible that diseased lungs simply trap particles differently than healthy ones.”
“…findings,” he said. “This shows that microplastics were detected more frequently and in greater quantities in patients with lung cancer, raising important questions for future research. We have already begun additional laboratory experiments to better understand which types of plastic are involved and how they might interact with lung cells.”
Dimeas and his colleagues are now continuing their work by analyzing samples from patients with chronic lung diseases to determine whether microplastics might play a role in lung scarring and overall disease progression.
Professor Barbara Hoffmann, Chair of the European Respiratory Society’s Advocacy Council at the University of Düsseldorf, noted that lung cancer remains the most common type of cancer worldwide and a leading cause of cancer-related deaths.
The disease accounts for approximately 2.5 million cases and 1.8 million deaths annually, with smoking remaining the primary cause.
She pointed out that air pollution is also a cause of lung cancer and a contributing factor to other lung conditions, such as asthma and COPD.
“Research into the health effects of microplastics is still in its early stages, but we are beginning to understand that these tiny plastic particles penetrate many parts of the body,” Hoffmann said. “This study adds to the evidence that we inhale microplastics from the air and that they settle in our lungs. We need further research to fully understand their potential role in the development of lung diseases, including cancer. In the meantime, we advocate for the fundamental human right to breathe clean air—and that includes air free from microplastic pollution.”
About the Author
