Li J, et al. Am J Respir Crit Care Med 2020.
RATIONALE: Limited cohort studies have evaluated chronic effects of high fine particulate matter (PM2.5) exposure on lung cancer.
OBJECTIVES: To investigate the response pattern of lung cancer associated with high PM2.5 exposure.
METHODS: A Chinese cohort of 118,551 participants was followed up from 1992 to 2015. By incorporating with PM2.5 exposure at 1 km spatial resolution during 2000-2015 generated using the satellite-based model, we estimated the association between lung cancer and time-weighted average PM2.5 concentration using Cox proportional hazard models.
MEASUREMENTS AND MAIN RESULTS: 844 incident lung cancer cases were identified during 915,053 person-years of follow-up. Among them, 701 lung cancer deaths occurred later. The exposure-response curves for lung cancer associated with PM2.5 exposure were non-linear, with steeper slopes at the higher concentration. Adjusted for age, sex, geographical region, urbanization, education level, smoking status, alcohol consumption, work-related physical activity and body mass index, participants exposed to the 2nd-5th quintiles of PM2.5 had higher risk for lung cancer incidence than the 1st quintile, with hazard ratios of 1.44 (95% confidence interval [CI]: 1.10-1.88), 1.49 (95% CI: 1.12-1.99), 2.08 (95% CI: 1.42-3.04) and 2.45 (95% CI: 1.83-3.29), respectively. The corresponding hazard ratios for lung cancer mortality were 1.83 (95% CI: 1.33-2.50), 1.80 (95% CI: 1.29-2.53), 2.50 (95% CI: 1.62-3.86) and 2.95 (95% CI: 2.09-4.17), respectively.
CONCLUSIONS: We provides strong evidence that high PM2.5 exposure leads to elevated risk of lung cancer incidence and mortality, highlighting that remarkable public health benefits could be obtained from improvement of air quality in highly polluted regions.