A new study published in The Lancet reveals that air pollution is causing an increase in lung cancer cases among non-smokers, especially women and Southeast Asians. Researchers found that adenocarcinoma, a lung cancer subtype, is prevalent among non-smokers, accounting for 53% to 70% of cases. The highest rates were observed in East Asia, particularly China, where household fuel burning contributes to pollution. While smoking rates decline globally, lung cancer among non-smokers is now the fifth leading cause of cancer-related deaths.