Higher Pulmonary Microplastic Burden Observed in Patients With Lung Cancer

Microplastic particles were detected more frequently in the lungs of patients with lung malignancies than in those without lung cancer, according to findings presented at the European Respiratory Society (ERS) Congress 2026. Although the study adds to evidence that inhaled plastics can reach and remain in human lungs, its observational design cannot determine whether microplastics contribute to cancer development or whether diseased lungs retain the particles differently.¹

Investigators Compare Lung Samples From 100 Patients

The prospective observational study included 100 patients undergoing diagnostic bronchoscopy. Half had newly diagnosed lung malignancies, whereas the control group underwent bronchoscopy for nonchronic respiratory indications. All participants provided bronchoalveolar lavage (BAL) samples, and paired airway tissue samples were available for approximately half of the cohort.¹

Microplastics were detected in approximately 70% of participants and 60% of all collected samples. Detection in BAL or airway tissue occurred more frequently among patients with lung cancer than controls, at 66% and 46%, respectively (P = .044). Patients with lung malignancies had a median of 1 microplastic particle detected in BAL samples, compared with 0 among patients without malignancy (P = .045).¹

After adjusting for age, sex, and smoking exposure, a higher microplastic burden remained associated with lung malignancy (OR, 2.00; 95% CI, 1.01-3.95). Among those with both BAL and tissue samples, investigators also observed significantly greater total microplastic burden and overall detection among those with lung cancer.¹

An inverse relationship between BAL and tissue microplastic burdens emerged within the lung malignancy group. Investigators said this finding could reflect compartment-specific particle dynamics, in which particles are deposited, retained, or cleared differently across pulmonary tissues and airway fluid.¹

Association Does Not Establish Causation

The results do not show whether microplastics were present before cancer developed. Lung tumors or other disease-related changes could affect particle deposition and clearance, leaving patients with malignancies more likely to retain inhaled material. Potential differences in occupational exposure, ambient air pollution, underlying pulmonary disease, prior medical procedures, and cancer type or stage also require further study.¹

Sample contamination is another challenge in microplastic research. Collection equipment, laboratory materials, and analytical procedures can introduce plastic particles unless investigators apply stringent controls. The small cohort and lack of longitudinal follow-up further limit conclusions about cancer risk.

Earlier research has confirmed that microplastics can be recovered from human lung tissue. Investigators of a 2022 analysis identified 39 microplastics across 11 of 13 tissue samples collected during surgery. Particles were detected in upper, middle, and lower regions of the lungs, with the greatest levels found in lower-lung tissue.²

Microplastics are defined as plastic particles measuring between 1 nanometer and 5 millimeters. They can be manufactured at a small size or form through the breakdown of larger items, including food packaging, tires, and synthetic textiles. Their varied sizes, shapes, densities, and chemical compositions have made standardized sampling and measurement difficult.³

Biological Plausibility Requires Clinical Confirmation

Laboratory and animal data offer several hypotheses for how inhaled microplastics could affect pulmonary health. Experimental studies have linked exposure with oxidative stress, inflammatory signaling, cellular injury, and impaired mitochondrial function. Particle characteristics and chemicals carried on their surfaces could influence these effects; however, experimental exposure levels may exceed those encountered in daily life. A review of research on microplastics and respiratory health concluded that the particles can affect lung cells and tissue, but the consequences of routine environmental exposure remain uncertain.⁴ A separate rapid systematic review rated the evidence for pulmonary injury, chronic inflammation, oxidative stress, and impaired lung function as moderate, while emphasizing the scarcity of human studies.⁵

For oncology pharmacists, the findings do not support changes to cancer treatment, screening, or patient counseling. They instead highlight an emerging environmental-health question relevant to prevention research and risk communication. Pharmacists should distinguish the observed association from proof of causation when patients raise concerns about microplastic exposure.

Future studies should be larger, prospective, and characterize polymer types. Additionally, they should measure occupational and environmental exposures, account for tumor features, and follow participants over time. Standardized collection and analytical methods will also be necessary to determine whether pulmonary microplastic burden precedes malignancy or results from changes within cancer-affected lungs.

REFERENCES

1. Lou N. More evidence ties microplastics to lung cancer. MedPage Today. Published September 6, 2026. Accessed September 15, 2026. https://www.medpagetoday.com/meetingcoverage/ers/122907

2. Jenner LC, Rotchell JM, Bennett RT, Cowen M, Tentzeris V, Sadofsky LR. Detection of microplastics in human lung tissue using μFTIR spectroscopy. Sci Total Environ. 2022;831:154907. doi:10.1016/j.scitotenv.2022.154907

3. US Environmental Protection Agency. Microplastics research. Updated March 19, 2026. Accessed September 15, 2026. https://www.epa.gov/water-research/microplastics-research

4. Vasse GF, Melgert BN. Microplastic and plastic pollution: impact on respiratory disease and health. Eur Respir Rev. 2024;33(172):230226. doi:10.1183/16000617.0226-2023

5. Chartres N, Cooper CB, Bland G, et al. Effects of microplastic exposure on human digestive, reproductive, and respiratory health: A rapid systematic review. Environ Sci Technol. 2024;58(52):22843-22864. doi:10.1021/acs.est.3c09524