How do people in different places experience different levels of air pollution? Using worldwide Chinese as a lens.

Air pollution, being especially severe in the fast-growing developing world, continues to post a threat to public health. Yet, few studies are capable of quantifying well how different groups of people in different places experience different levels of air pollution at the global scale. In this paper, we use worldwide Chinese as a lens to quantify the spatiotemporal variations and geographic differences in PM2.5 exposures using unprecedented mobile phone big data and air pollution records. The results show that Chinese in South and East Asia suffer relatively serious PM2.5 exposures, where the Chinese in China have the highest PM2.5 exposures (52.8 μg/m3/year), which is fourfold higher than the exposures in the United States (10.7 μg/m3/year). Overall, the Chinese in Asian cities (35.5 μg/m3/year) experienced the most serious PM2.5 exposures when compared with the Chinese in the cities of other continents. These results, partly presented as a spatiotemporally explicit map of PM2.5 exposures for worldwide Chinese, help researchers and governments to consider how to address the effects of air pollution on public health with respect to different population groups and geographic locations.