On World Lung Cancer Day, experts are highlighting an emerging discovery that may explain why two people exposed to the same level of air pollution can have very different risks of developing lung cancer. While polluted air remains one of the leading environmental causes of lung cancer, new research suggests that an age-related blood condition called clonal hematopoiesis could make some individuals far more vulnerable than others.
A 2026 study published in the Journal of the National Cancer Institute analysed data from more than 650,000 participants and identified clonal hematopoiesis as a possible biological factor that increases susceptibility to pollution-related lung cancer. The findings point toward a future where cancer prevention may become increasingly personalized rather than based solely on environmental exposure.
What is clonal hematopoiesis?
According to Dr. Aravind Badiger, Technical Director, BDR Pharmaceuticals International Pvt. Ltd., clonal hematopoiesis is not a disease but a natural age-related process in which genetic mutations gradually develop in blood-forming stem cells. “Mutations make it possible for certain blood cells to proliferate and grow, without causing any symptoms in the individuals. Over the last decade, there have been connections established between clonal haematopoiesis and the risk of developing cardiovascular disease and chronic inflammation,” he said.
The latest research suggests these altered immune cells may also change how the lungs respond to air pollution. Instead of repairing damage caused by harmful pollutants, the immune system may trigger excessive inflammation, creating an environment where cancer is more likely to develop.
Why does air pollution not affect everyone the same?
Air pollution damages the lungs by causing oxidative stress, inflammation, and DNA damage. However, not everyone’s body responds to these harmful effects in the same way. Dr. Badiger says an individual’s lung cancer risk depends on a combination of environmental and biological factors, including:
- Biological ageing: The likelihood of developing clonal hematopoiesis increases with age, making inflammatory responses less effective.
- Genetic predisposition: Inherited genetic variations influence how efficiently damaged DNA is repaired.
- Overall health: Existing respiratory diseases, cardiovascular conditions, or weakened immunity can amplify pollution-related damage.
- Lifestyle choices: Smoking, occupational exposure to harmful chemicals, poor diet, and lack of physical activity further increase lung cancer risk.
“This complex interaction explains why two people living in the same city and breathing similar air may experience very different health outcomes. Environmental pollutants harm the lungs by inducing oxidative stress, inflammation, and DNA damage. Nevertheless, the capability of repairing this damage greatly differs from person to person,” he added.
Breathing polluted air could damage your DNA
A new era of personalised cancer prevention
The findings reinforce that reducing exposure to air pollution remains essential, but it may not be the only strategy needed to prevent lung cancer. Researchers believe future risk assessments could combine pollution exposure with biological markers like clonal hematopoiesis to identify people who would benefit from earlier screening and closer medical monitoring.
Although routine screening for clonal hematopoiesis is not currently recommended, ongoing research may help doctors identify high-risk individuals before cancer develops. “This approach aligns with the growing field of precision medicine, where prevention and treatment are tailored to a person’s unique biology,” said Dr. Badiger.
Protecting your lung health
While scientists continue studying these biological risk factors, experts recommend practical steps to lower lung cancer risk:
- Limit exposure to polluted air by checking air quality levels and using protective measures during high-pollution days.
- Avoid cigarette smoking and secondhand smoke.
- Maintain good indoor ventilation to reduce harmful pollutants.
- Seek medical evaluation for persistent cough, breathlessness, or other long-lasting respiratory symptoms.
- Adopt healthy lifestyle habits, including regular exercise and a balanced diet that helps reduce chronic inflammation.
- Attend recommended health check-ups and lung cancer screening if you are at high risk.
As science uncovers the hidden biological factors behind lung cancer, experts say the future of prevention will likely combine cleaner environments with personalized risk assessment, helping identify those most vulnerable long before disease develops.