Published July 25, 2025
Air Pollution Linked to Cancer-Causing Gene Changes in Nonsmokers
Lung cancer is the leading cause of cancer death in both men and women. For nonsmokers, air pollution may be an even greater risk factor for lung cancer than secondhand tobacco smoke, a study published in Nature suggests.
Although cigarette smoking contributes to the majority of lung cancer incidence, about a quarter of cases occur in people who have never smoked. A whole-genome analysis of 871 never-smokers with lung cancer from 28 global geographical locations found that second-hand smoke exposure correlated with a slightly higher burden of genetic changes and shorter telomeres—the protective caps at the ends of chromosomes. But second-hand smoke exposure wasn’t linked to more cancer-driving gene alterations compared with those who weren’t exposed.
Patients from areas with high levels of fine-particulate air pollution from vehicles and industry, however, exhibited an increase in most types of genetic changes. As air pollution levels rose, gene changes previously associated with tobacco smoking also increased, while telomere length decreased. The authors noted that although prior genomic studies have largely focused on tobacco smokers, these findings underscore the importance of environmental factors in lung cancer cases among nonsmokers.