Microplastic accumulation in the human lung: distinct signatures in lung cancer vs normal tissue

Abstract Microplastics (MPs; <5 mm) are increasingly detected in human tissues, yet their relationship to lung cancer remains unclear. We conducted a pilot study comparing MP burden and characteristics in cancerous and non-cancerous lung tissue. Twenty cryopreserved samples (10 cancer, 10 controls) were processed using potassium hydroxide digestion, followed by Raman microspectroscopy for polymer identification. MPs were detected in all specimens. Cancer tissues showed a higher median MP count (39.0 vs 31.5 particles per ∼100 mg), although this difference was not statistically significant (OR 1.009 per particle, 95% CI 0.982–1.036). Polypropylene, polyethylene, and polyethylene terephthalate accounted for 78% of particles, with higher proportions of polypropylene and PET in cancer samples. Fibers predominated overall and were more frequent in cancer tissue, as were smaller particles (<50 µm). These findings suggest distinct microplastic signatures in lung cancer, supporting further investigation into their potential role in pulmonary carcinogenesis in larger, longitudinal studies.