Long-Term Exposure to Air Pollution Is a Risk Factor for Esophageal Cancer

Long-term exposure to PM2.5 (fine particulate matter) is a known risk factor for lung cancer. However, the evidence linking PM2.5 to esophageal cancer is sparse and inconclusive. Long-term exposure to PM2.5 can cause chronic low-grade inflammation and oxidative stress locally and systemically, which can trigger genetic changes that increase the risk of lung and non-lung cancer.

The study analyzed China’s Kadoorie Biobank and identified 510,125 participants who did not have esophageal cancer at the start. The study used a satellite-based model to estimate PM2.5 exposure during the study period. Using a Cox proportional hazard model, the study found a linear concentration-response relationship between PM2.5 exposure and esophageal cancer. For each 10 μg/m3 increase in PM2.5, the hazard ratio was 1.16 (95% confidence interval, 1.04-1.30) for esophageal cancer incidence. The study also found that the population-attributable risk due to PM2.5 exposure was higher than that due to lifestyle risk factors.