Satellite-based estimate of PM2.5 and the association with the risk of death in 505,808 Taiwanese adults

Abstract

Introduction There are a number of time-series studies showing the acute effects of particulate matter with aerodynamic diameter < 2.5 (PM2.5) on mortality worldwide. However, there is limited information on long-term effects of PM2.5 using large cohort study design in general populations, especially for Asian. We therefore investigate the association between PM2.5 and the risk of death in a prospective cohort with 505,808 Taiwanese adults. Methods This cohort consisted of Taiwanese who participated in a standard medical screening program between 1996 and 2011. The participants’ residential addresses were geo-coded into latitude and longitude data and then the PM2.5 levels at the addresses 1 x 1 kilometer grid were estimated by a remote-sensing algorithm based on the NASA satellite data. Information on health and potential confounders was from the medical checkup and vital information was obtained by matching the death registry system. The Cox proportional regression models were used to investigate the relative risk of death with PM2.5 in this large Asian cohort. Results The mean age of the population was 40 years old, and 52.2% of the participants were female. The participants were followed up between 1996 and 2011 with a mean follow-up period of 9.7 years, and a total of 18350 death occurred. A significantly increased hazard ratio (HR) for PM2.5 of 1.05 (95% CI: 1.03-1.07) per 10 µg/m3 was observed after adjusting for age, sex, education, smoking, drinking, and physical activity. The significant associations remained in the analyses stratified by smoking status (for never smokers, HR: 1.06, 95% CI: 1.04-1.09; for ever smokers, HR: 1.03, 95% CI: 1.00-1.06) Conclusions Long-term exposure to PM2.5 air pollution is associated with higher risk of death in Asian populations.