Key TakeawaysLung cancer might be linked to hidden deposits of microplasticsPeople with lung cancer were more likely to have microplastics in their lungsThey also were more likely to have heavier loads of microplastics.TUESDAY, Sept. 8, 2026 (HealthDay News) — People with lung cancer are more likely to have hidden deposits of microplastics in their lungs, a new study says.About 66% of lung cancer patients had detectable microplastics found in fluid samples taken from their lungs, compared to 46% of people without lung cancer, researchers reported Sunday at a meeting of the European Respiratory Society in Barcelona, Spain.Lung cancer patients also were twice as likely to have heavier loads of microplastics in their lungs, researchers said.“Our results suggest that inhaled microplastics can be found in the human lung more frequently than many people may realize,” said researcher Dr. Ilias Dimeas, a respiratory physician from the University College Dublin School of Medicine.“This adds to the growing evidence that reducing environmental plastic pollution may have benefits that extend beyond ecosystems and into human health,” Dimeas said in a news release.Microplastics can be inhaled and lodge deeply in the lungs, researchers said in background notes.“Microplastics have become an unavoidable part of our environment, but we still know remarkably little about what happens once they enter the human body,” Dimeas said. “We don't yet know what the background levels of microplastics in the lungs are, how much they vary from person to person, or whether they contribute to disease.“If we are breathing these particles in every day, we need to understand where they end up and whether they could be linked to disease,” Dimeas said.For the new study, researchers recruited 100 patients who were undergoing a bronchoscopy to investigate lung symptoms at the University Hospital of Larissa in Greece. The procedure involves a thin flexible tube fed into the lungs, allowing doctors to examine the inside of the lungs and take samples.As part of the process, patients also underwent a lung wash, in which a saline solution is used to flush a section of their lung.Of the 100 patients, 50 were later diagnosed with lung cancer.Analysis showed that 70% of patients overall had detectable microplastics in either their lung wash fluid or lung tissue samples, researchers said.More patients with lung cancer had detectable microplastics in their lung wash samples, and they had a higher overall microplastic burden than those without cancer.Those with heavier microplastic loads were twice as likely to have lung tumors, researchers found.“Research on the health effects of microplastics is still at a very early stage, but we are starting to realize that these tiny pieces of plastic are infiltrating many parts of the body,” said Dr. Barbara Hoffman, chair of the European Respiratory Society’s Advisory Council, who reviewed the findings.“This study adds to evidence that we are breathing microplastics in via the air and they are lodging in our lungs. We need more research to fully understand their potential role in lung diseases, including cancer,” Hoffman noted in a news release.The most common types of plastic found in the lungs were polypropylene and polyethylene, which are widely used in everyday products like packaging, textiles, household materials and consumer goods.“This type of study doesn’t tell us why we found more microplastics in the samples from lung cancer patients,” Dimeas said. “Microplastics could contribute to inflammation or other biological processes that may contribute to diseases like cancer, but it is also possible that diseased lungs simply retain particles differently than healthy lungs.“What it does show is that microplastics were found more often and in greater numbers in patients with lung cancer, which raises important questions for future research,” Dimeas said. “We have already begun more laboratory experiments to better understand the types of plastics involved and how they may interact with lung cells.”Dimeas’ team also is analyzing samples from patients with lung diseases to better understand how microplastics might play a role in lung scarring and disease progression.Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.More informationStanford University has more on microplastics and human health.SOURCE: European Respiratory Society, news release, Sept. 6, 2026 .What This Means For YouInhaled microplastics might be linked to lung cancer..Sign up for our weekly HealthDay newsletter