A new genomic study has revealed that air pollution may be a major contributor to lung cancer in people who have never smoked—especially women of Asian ancestry. Researchers from UC San Diego and the National Cancer Institute analyzed lung tumors from 871 never-smokers across 28 regions and found a strong link between pollution exposure and cancer-driving mutations.
“We’re seeing this problematic trend that never-smokers are increasingly getting lung cancer,” said Ludmil Alexandrov, co-senior author of the study. “Our research shows that air pollution is strongly associated with the same types of DNA mutations we typically associate with smoking.”
The study found a 3.9-fold increase in a mutational signature linked to tobacco and a 76% increase in one linked to aging among those exposed to high levels of pollution. These individuals also had shorter telomeres, a marker of accelerated cellular aging.
While secondhand smoke showed only a slight increase in mutations, the study identified another unexpected risk: aristolochic acid, a carcinogen found in some traditional Chinese herbal medicines. This mutational signature was found almost exclusively in lung cancer cases from Taiwan.
Researchers also discovered a new mutational signature common in never-smokers but absent in smokers, with no known environmental cause. “It opens up a whole new area of investigation,” said Alexandrov.
The findings highlight the urgent need for targeted prevention strategies and more research into environmental risks affecting minority communities.
See: “Air Pollution May Contribute to Development of Lung Cancer in Never-smokers, New Study Finds” (July 2, 2025)
