Ambient cumulative pm2.5 exposure and the risk of lung cancer incidence and mortality: A retrospective cohort study

Abstract

Smoking, sex, air pollution, lifestyle, and diet may act independently or in concert with each other to contribute to the different outcomes of lung cancer (LC). This study aims to explore their associations with the carcinogenesis of LC, which will be useful for formulating further pre-ventive strategies. This retrospective, longitudinal follow-up cohort study was carried out by con-necting to the MJ Health Database, Taiwan Cancer Registry database, and Taiwan cause of death database from 2000 to 2015. The studied subjects were persons attending the health check-ups, dis-tributed throughout the main island of Taiwan. Cox proportional hazards regression models were used to investigate the risk factors associated with LC development and mortality after stratifying by smoking status, with a special emphasis on ambient two-year average PM2.5 exposure, using a satellite-based spatiotemporal model at a resolution of 1 km2, and on dietary habit including con-sumption of fruits and vegetables. After a median follow-up of 12.3 years, 736 people developed LC, and 401 people died of LC-related causes. For never smokers, the risk of developing LC (aHR: 1.32, 95%CI: 1.12–1.56) and dying from LC-related causes (aHR: 1.28, 95%CI: 1.01–1.63) rises significantly with every 10 μg/m3 increment of PM2.5 exposure, but not for ever smokers. Daily consump-tion of more than two servings of vegetables and fruits is associated with lowering LC risk in ever smokers (aHR: 0.68, 95%CI: 0.47–0.97), and preventing PM2.5 exposure is associated with lowering LC risk for never smokers.