Metabolite Shifts Tied to Air Pollution Found Years Before Lung Cancer in Never-Smokers

The Nature Communications study examined metabolomic profiles from stored blood samples collected years before diagnosis. Exposure estimates for fine particulate matter and nitrogen dioxide correlated with disruptions in pathways for inflammation, oxidative stress, detoxification, and energy metabolism. These shifts appeared strongest among never-smokers, a group often excluded from current screening guidelines despite rising lung cancer incidence. Long-term personal exposure at levels common in many U.S. cities was associated with cumulative metabolic strain that may accelerate carcinogenesis even without tobacco use. Individuals living near high-traffic corridors or in regions with persistent PM2.5 above 8 µg/m³ face repeated daily insults that compound over decades, elevating lifetime risk through mechanisms now measurable in circulation. The findings highlight how air pollution operates as a chronic, low-level carcinogen whose effects accumulate silently until clinical thresholds are crossed. Next steps require prospective validation cohorts and integration of metabolite panels into risk models to test whether they improve identification of high-risk never-smokers for targeted screening or exposure-reduction interventions.