Air Pollution Linked to Lung Cancer Mutations in Non-Smokers, Study Finds

A new study published in Nature reveals that air pollution may drive cancerous mutations in lung cells—even among individuals who have never smoked. Scientists found that residents of highly polluted areas are at increased risk of developing lung cancer due to DNA damage, including mutations that disable tumor-suppressing genes.

Globally, around 2.5 million new lung cancer cases are reported annually, a figure projected to surpass 4.5 million by 2050. While smoking remains the primary cause, roughly 25% of lung cancer cases occur in non-smokers, with air pollution emerging as a significant contributor. Higher lung cancer incidence is consistently observed in regions with poor air quality.

To explore the underlying mechanisms, researchers from the University of California, San Diego, and the U.S. National Cancer Institute analyzed DNA from nearly 900 non-smoking lung cancer patients, correlating genetic mutations with the air pollution levels of their residential areas. They discovered that patients in highly polluted cities like Milan and New York exhibited substantially more DNA mutations than those from rural regions.

The human genome consists of approximately 6 billion DNA base pairs. Excessive alterations to these base pairs can disrupt genetic instructions and impair critical tumor suppressor genes, such as TP53. Notably, some mutations found in non-smokers exposed to air pollution closely resembled those seen in smokers, suggesting that both pollutants and tobacco smoke may damage DNA through similar biological pathways.

The research team is now investigating the effects of e-cigarettes and cannabis on the genome. While such lifestyle choices are modifiable risk factors, exposure to air pollution is far more difficult to avoid. These findings underscore the urgent need for stronger air quality regulations and pollution control measures worldwide.