Lung Cancer Risk and Residential Exposure to Air Pollution: A Korean Population-Based Case-Control Study

Purpose: To investigate the association between long-term exposure to ambient air pollution and lung cancer incidence in Koreans. Materials and Methods: This was a population-based case-control study covering 908 lung cancer patients and 908 controls selected from a random sample of people within each Korean province and matched according to age, sex, and smoking status. We developed land-use regression models to estimate annual residential exposure to particulate matter (PM10) and nitrogen dioxide (NO2) over a 20-year exposure period. Logistic regression was used to estimate odds ratios (ORs) and their corresponding 95% confidence intervals (CI). Results: Increases in lung cancer incidence (expressed as adjusted OR) were 1.09 (95% CI: 0.96-1.23) with a ten-unit increase in PM10 (mu g/m(3)) and 1.10 (95% CI: 1.00-1.22) with a ten-unit increase in NO2 (ppb). Tendencies for stronger associations between air pollution and lung cancer incidence were noted among never smokers, among those with low fruit consumption, and among those with a higher education level. Air pollution was more strongly associated with squamous cell and small cell carcinomas than with adenocarcinoma of the lung. Conclusion: This study provides evidence that PM10 and NO2 contribute to lung cancer incidence in Korea.