Objective To determine the short-term effect of particulate matter of <2.5 μm (PM2.5) and particulate matter of <10 μm (PM10) on non-accidental emergency visits. Methods A time-series study analysis with generalized additive model was performed to establish the associations between air pollution (indicated by PM2.5 and PM10) and non-accidental emergency visits in the West China Hospital of Sichuan University over the period from 2014 to 2016, categorized by age (<65 and ≥65 yr.). Results From January 1, 2014 to November 30, 2016, the Chengdu urban area had an annual average concentration of 66.47 μg/m3 PM2.5 and 109.35 μg/m3 PM10, respectively. The peak short-term effect of particulate matters on non-accidental emergency visits appeared one day after the exposure, with a daily increase of 10 μg/m3 for PM2.5 and PM10 resulting in an increase of 0.634% (95%CI: 0.273%-0.997%) and 0.413% (95%CI: 0.166%-0.660%) non-accidental emergency visits, respectively. For those ≥65 yr., a daily increase of 10 μg/m3 for PM2.5 and PM10 resulted in 1.439% (95%CI：0.599%-2.287%) and 1.150% (95%CI：0.566%-1.738%) increase in non-accidental emergency visits, respectively, after adjustment for all gaseous pollution. Conclusion High levels of PM2.5 and PM10 are associated with increased non-accidental emergency visits. Older people (over 65 years) are more sensitive to the acute health damage associated with PM2.5 and PM10.
