Breathing Trouble: Meta-Analysis Links Inhaled Pollutants to Higher Risk of GERD, Ulcers, and GI Cancers

The researchers sifted through 1,800+ articles across PubMed and Web of Science, ultimately including 111 studies that met stringent eligibility criteria.

Based on the study, the researchers reported the following findings:

• Exposure to airborne pollutants was significantly associated with an increased risk of several upper gastrointestinal disorders.
• The highest risk was observed for esophageal cancer, with a pooled odds ratio (OR) of 1.83.
• Gastric cancer also showed a notable risk increase, with an OR of 1.71.
• Gastroesophageal reflux disease (GERD) had a similar elevated risk, with an OR of 1.71.
• Esophagitis was linked to inhalational exposures with an OR of 1.32.
• Peptic ulcer disease showed a moderate association, with an OR of 1.21.
• No significant association was found between inhalational exposures and Barrett’s esophagus, with a pooled OR of 0.93, indicating selective vulnerability among upper GI conditions.

The authors emphasized that while inhalational exposures are widely recognized for their effects on respiratory health, their role in gastrointestinal diseases has been underappreciated. “Our findings highlight the need to consider digestive health when evaluating the broader impact of air pollution and tobacco-related exposures,” the study noted.

Notably, most of the included studies were rated as high-quality in the risk-of-bias assessment, lending credibility to the review’s conclusions. Sensitivity analyses further supported the robustness of the associations.

The study also highlighted significant gaps in the literature, particularly the lack of human data regarding newer inhalational agents such as e-cigarettes and marijuana smoke. Given the long latency between exposure and the onset of cancers, the authors suggest that ongoing and future research should include these substances, along with potential occupational hazards such as asbestos, synthetic fibers, and dust exposure common in mining and textile industries.

From a public health standpoint, the implications are substantial. The findings underscore the importance of implementing strategies to limit exposure to air pollutants and promote smoking cessation to reduce the incidence of upper GI conditions. The review also advocates for expanding screening protocols in populations with known environmental or occupational inhalation exposure, who are often overlooked in routine GI assessments.

The researchers concluded, "The study reinforces the critical link between inhalational exposures and upper gastrointestinal health. It calls for greater awareness, further research into emerging risk factors, and targeted interventions aimed at reducing the burden of these often preventable digestive diseases."

Reference:

Kim, D. H., Podury, S., Fallah Zadeh, A., Mahmoodi, T., Kwon, S., Grunig, G., Liu, M., & Nolan, A. (2025). Gastroesophageal disease risk and inhalational exposure a systematic review and meta-analysis. Scientific Reports, 15(1), 1-23. https://doi.org/10.1038/s41598-025-06620-7