Study uncovers pre-cancerous link between air pollution exposure and lung cancer risk
A new study, published in Nature Communications, found measurable changes in people’s blood relative to their exposure to air pollution and subsequent development of lung cancer. The findings provide promising clues that could help shape future cancer research, detection, and prevention strategies.
Air pollution exposure is already widely recognized as a key environmental cause of lung cancer. However, less is known about what changes in a person’s body following exposure to air pollution that leads to these adverse health effects.
This new study-led by researchers at the American Cancer Society (ACS) and Emory University’s Rollins School of Public Health—found molecular signs of changes in the blood of people who had been exposed to air pollution and these changes were detectable several years before participants were diagnosed with lung cancer.
The researchers analyzed blood samples from 1,357 cancer-free people in the ACS Cancer Prevention Study cohorts and found changes in small molecules, called metabolites, that were linked to higher long-term air pollution exposure. These disruptions to the body’s normal chemistry involved inflammation, oxidative stress, detoxification, and energy metabolism, which are associated with increased lung cancer risk.
WHY THIS MATTERS
Lung cancer is the leading cause of cancer death in the U.S. and long-term exposure to ambient air pollution is a well-established environmental risk factor for lung cancer and other respiratory diseases, including asthma and chronic obstructive pulmonary disease. However, regular lung cancer screenings are currently only recommended for adults aged 50-80 years old with a substantial history of tobacco smoking.
The air pollution-related biological changes the study identified could guide future development of blood-based biomarkers to help identify more people with higher lung cancer risks and strengthen the evidence for prevention-focused public health strategies.
WHAT THE EXPERTS SAY
“Outdoor air pollution is classified as a human carcinogen, and in epidemiologic studies the association with lung cancer is often strongest among people who have never smoked,” says Ying Wang, PhD, senior principal scientist of epidemiology research at the American Cancer Society, and a co-senior author of the study. “That tells us something meaningful is happening biologically, but we still don’t understand the mechanisms. Studies like this one, which look at what is measurably changing in the body years before a diagnosis, are how we begin to close that gap.”
“Although smoking is a key risk factor for lung cancer, more than half of lung cancer is diagnosed among people who never smoke or who have ever smoked but ineligible for lung cancer screening. Understanding non-smoking related risk factors, such as air pollution, is important for cancer prevention and early detection. But the fact that these environmental risk factors are not even considered in the lung cancer screening recommendations highlights that there's still so much unknown about how air pollution contributes to lung cancer,” says Donghai Liang, PhD, associate professor of environmental health at the Rollins School of Public Health and a co-senior author of the study.
“What is especially exciting about this study is that we now identified measurable changes in human blood metabolome associated with air pollution exposure years before lung cancer was diagnosed,” Liang adds. “These new findings give us a clearer picture of the biological processes connecting air pollution and lung cancer. And with further validation, maybe one day, it could help us identify people at elevated risk and determine whether air pollution exposure should be considered in future prevention and screening strategies.”
Reference:
Chow, S.S., Wang, Y., Sarnat, J.A. et al. Blood metabolomic signatures linking air pollution to lung cancer in the Cancer Prevention Studies. Nat Commun 17, 7255 (2026). https://doi.org/10.1038/s41467-026-75116-3
