Patients with lung cancer showed a higher burden of respiratory microplastics than patients without cancer in a paired analysis of airway and lung tissue samples, according to data presented at the European Respiratory Society (ERS) Congress 2026 in Barcelona, Spain, held September 5 to 9.1
Inhalation is an increasingly recognized route of human exposure to airborne microplastics, but data from paired airway and tissue respiratory compartments have remained scarce, according to the study investigators.1 Researchers led by Ilias Dimeas, MD, of University College Dublin School of Medicine and the University of Thessaly, prospectively collected paired bronchoalveolar lavage (BAL) and lung tissue samples from adults undergoing diagnostic bronchoscopy. The analysis aimed to quantify microplastic burden and its relationship to clinical diagnosis.1
“Microplastics have become an unavoidable part of our environment, but we still know remarkably little about what happens once they enter the human body,” said Dimeas, who presented the findings.2 “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.”
Microplastic burden and compartmental distribution
Investigators enrolled 100 adults undergoing bronchoscopy for lung symptoms at University Hospital of Larissa, Thessaly, Greece, including 50 subsequently diagnosed with lung cancer and 50 who were not. Each patient provided a BAL sample, and roughly half also provided a lung tissue biopsy. Microplastics were isolated from all samples under strict contamination control and characterized by stereo-microscopy, with 40% of particles undergoing micro-Raman spectroscopy for polymer identification.1,2
Across the full cohort, investigators identified 232 microplastic particles, and 70% of patients had detectable microplastics in at least 1 sample.2 Patients with lung cancer were more likely to have detectable microplastics in BAL than patients without cancer (66% versus 46%) and had a higher overall microplastic burden.2 In a paired-sample analysis, investigators identified 186 microplastics across 100 paired BAL and tissue samples, predominantly fragments (88.2%), with total burden significantly higher in patients with malignancy (P = .025).1
Plastic composition and compartmental discordance
Total microplastic counts correlated strongly with BAL counts (ρ = 0.66; P <.001) but not with tissue counts (ρ = -0.18; P = .203), indicating compartmental discordance between airway and tissue compartments.1 Within the malignancy subgroup, BAL and tissue microplastic counts showed a significant inverse correlation (ρ ≈ -0.60; P = .001), suggesting particles retained in the airway and particles embedded in tissue may not track together in the same patient.1 Raman-characterized particles showed a non-random distribution by diagnosis, with fluorescence-only particles enriched in epithelial malignancies (χ² P = .023).1
Because BAL samples capture particles from the airspaces while tissue samples capture particles embedded within the lung, investigators said the inverse relationship suggests microplastics may not be distributed evenly throughout the lung, with different regions retaining particles differently.2 Polypropylene and polyethylene, both widely used in packaging, textiles, and consumer goods, were the most common plastic types identified across samples.2
“We need more research to fully understand their potential role in lung diseases, including cancer,” said Barbara Hoffmann, MD, chair of the ERS Advocacy Council at the University of Dusseldorf, who was not involved in the research.2
Dimeas and colleagues are continuing laboratory work to characterize the plastic types identified and how they may interact with lung cells.2 They are separately analyzing samples from patients with chronic lung disease to assess whether microplastics contribute to lung scarring and disease progression.2 The findings will be presented in the occupational and environmental health session at the congress.
References
Dimeas IE, Zakynthinos GE, Salmas C, et al. High respiratory microplastic burden across paired airway and tissue samples in patients with lung cancer. Abstract 1291. Presented at: European Respiratory Society (ERS) Congress 2026; September 5-9, 2026; Barcelona, Spain.
