September 3, 2026

expert reaction to unpublished study on microplastic burden in lungs found in lung cancer diagnoses

Scientist comments on an unpublished study exploring microplastic burden in lungs found in lung cancer diagnosis, as presented at the European Respiratory Society Congress 2026.

Dr Ria Devereux, Environmental Research Fellow at the University of East London’s Sustainability Research Institute, said:

Does the press release accurately reflect the science? Is it responsibly written?

“There were 100 participants in total: 50 with lung malignancy and 50 bronchoscopy controls. 50 participants had paired lung tissue and BAL samples (26 malignancy and 24 control); all 100 participants had BAL samples.

It is not clear whether all participants with lung malignancy had a previously known diagnosis at the time of bronchoscopy, or whether some were undergoing their first diagnostic bronchoscopy. If participants had undergone previous bronchoscopies or other procedures, this could potentially explain the higher levels of microplastic fragments.

Is this good quality research?  Are the conclusions backed up by solid data?

The samples included airway fluid (BAL) and lung tissue, which means you can look at samples from different areas of the respiratory system and not rely on just one sample type. The current research seems like a preliminary study which researchers can build on and further investigate.  Without further information, I cannot say whether this is good-quality research.

How does this work fit with the existing evidence?  Does it challenge it – and if so does it provide sufficient strong evidence to do so?

This study adds to the growing evidence that microplastics can be detected in the human body, including the respiratory system. The finding of microplastics in both BAL and lung tissue is consistent with human exposure to microplastics in the environment, including through inhalation.

However, as with much research on the potential impacts of microplastics on human health, this study does not establish causality. Finding microplastics in the lungs, and finding a higher burden in people with lung cancer, is not the same as demonstrating that microplastics cause cancer.

The findings therefore add to the evidence base and raise important questions for future research, but I would not consider them strong enough to establish a causal relationship between microplastics and lung cancer.

Have the authors accounted for confounders?  If not, do the confounders fatally undermine this study?

From the information available I cannot comment on if the authors accounted for confounders.

It appears the authors understand that the study doesn’t explain why. Why did they find more microplastics, and do diseased lungs retain more microplastics? There are several potentially important factors I would want to know before interpreting the association.

The author has accounted for Age, sex, and smoking history, which is important as we know smoking increases the risk of Lung cancer. However, I would still be interested to know occupational exposures, exposure to air pollution, other underlying lung diseases, the specific type and stage of lung cancer, and whether participants had undergone previous medical procedures or interventions that could affect microplastic exposure. Is it possible that the bronchoscopy itself added microplastics to the samples?

Without knowing whether these factors differed between the cancer and non-cancer groups, it is difficult to determine how much of the observed difference can be attributed specifically to lung cancer.

Are there important limitations to be aware of?  Are there any flaws or weaknesses in this work that journalists need to know about?

The study is small, with only 100 participants, and only 50 of those had both tissue and BAL sampled. Currently, this study is not peer-reviewed. That does not mean the findings are wrong, but it does mean that the methodology, statistical analysis and interpretation have not yet been independently scrutinised by other scientists.

It is also an observational study, so it can show association but not causation. Another important limitation is the participants. The participants were undergoing diagnostic bronchoscopy for some reason, which is not clear in the abstract or press release. This means they are not necessarily representative of the general population, and the non-malignant participants may not be equivalent to healthy individuals with no underlying respiratory problems. The study also cannot tell us how long the microplastic has been in the person’s lung or where it came from. It therefore cannot establish whether microplastics were present before the disease developed or whether differences in the diseased lung affected how particles were deposited or retained.

What are the implications in the real world?  Is there any overspeculation?

From this study, as scientists, we cannot say 100% that microplastics cause lung cancer or that they increase your individual risk of cancer. The study adds evidence that microplastics can be detected in the human respiratory system and that microplastic burden may differ between people with and without lung malignancy.

The findings contribute to a growing body of research suggesting that our reliance on plastic is not only an environmental issue, but may also have implications for human exposure and health. However, the potential health consequences remain an area requiring considerably more research.

This study is an important preliminary study, but it does not establish that microplastics are a cause or risk factor for lung cancer.”

* ‘High respiratory microplastic burden across paired airway and tissue samples in patients with lung cancer’ by Ilias E. Dimeas et al. was presented in session at European Respiratory Society Congress 2026 on Thursday 3rd September.

Declared interests

Dr Ria Devereux: “Dr Ria Devereux has nothing to declare”