Few studies have evaluated the short-term impacts of ambient particulate matter (PM) pollution on morbidity in China. The aims of this study were to examine the short-term association between hospital admissions and ambient PM and also to explore whether PM2.5 at levels below current regulatory limits also increases the risk of hospitalizations in 26 Chinese cities.Methods:
We identified 14,569,622 all-cause, 2,008,786 cardiovascular, and 916,388 respiratory admissions during 2014–2015. We employed conditional logistic regression to estimate the association between hospital admissions and ambient PM.Results:
A 10 μg/m3 increase in PM2.5 at lag 0 day corresponded to increases of 0.19% (95% confidence interval [CI] = 0.18%, 0.20%) in all-cause, 0.23% (95% CI = 0.20%, 0.26%) in cardiovascular, and 0.26% (95% CI = 0.22%, 0.31%) in respiratory admissions. For PM10, the values were 0.12% (95% CI = 0.11%, 0.13%) for all-cause, 0.15% (95% CI = 0.13%, 0.17%) for cardiovascular, and 0.21% (95% CI = 0.17%, 0.24%) for respiratory admissions. The associations held at PM2.5 levels below the current Chinese and European/WHO standards. Among individuals with exposure levels below 25 μg/m3, increasing PM2.5 levels from below 15 μg/m3 to above 15 μg/m3 was associated with increases of 1.8% (odds ratio, 1.018; 95% CI = 1.015, 1.022) in all-cause admissions and 2.5% (odds ratio, 1.025; 95% CI = 1.017, 1.034) in cardiovascular admissions.Conclusions:
Short-term PM exposures were associated with increased hospitalizations, even for exposure levels not exceeding the current regulatory limits.