Ilias E. Dimeas, George E. Zakynthinos, Christos Salmas, Athanasios D. Pagonis, Konstantinos N. Tourlakopoulos, Achilleas Sarris, Eleni Karetsi, Charalampos Varsamas, Ioannis Diamantis, Maria Giannaki, Paraskevi Kirgou, Sotirios I. Sinis, Maria Perraki, Cormac McCarthy, Michael P. Keane, Patrick D. Mitchell, Evangelos Oikonomou, Ioannis D. Papanikolaou, Zoe Daniil
Background: Inhalation is an increasingly recognised route of human exposure to airborne microplastics, yet data from paired airway and tissue respiratory compartments remain scarce.
Objective: To quantify microplastic burden and characterise particle features in paired bronchoalveolar lavage (BAL) and lung tissue samples, and to explore associations with clinical diagnosis and selected haematological parameters.
Methods: In this prospective observational study, 50 adults undergoing diagnostic bronchoscopy provided paired BAL and lung tissue samples. Microplastics were isolated under strict contamination control and characterised by stereo-microscopy; 40% underwent micro-Raman spectroscopy.
Results: Across 100 paired samples, 186 microplastics were identified, predominantly fragments (88.2%). Total microplastic burden was higher in patients with lung malignancy than in non-malignant participants (p=0.025). Total microplastic counts correlated strongly with BAL counts (ρ=0.66, p<0.001) but not with tissue counts (ρ=-0.18, p=0.203), indicating compartmental discordance. In the malignancy subgroup, BAL and tissue microplastic counts demonstrated a significant inverse correlation (ρ≈-0.60, p=0.001). Raman-characterised particles showed a non-random distribution by diagnosis, with fluorescence-only particles enriched in epithelial malignancies (χ² p=0.023).
Conclusion: Paired airway and tissue sampling reveals heterogeneous, compartment-specific distribution of respiratory microplastics, with higher burden in cancer.