The relationship between fine particulate matter and hospital outpatients with pediatric respiratory diseases in Shijiazhuang City

Objective To analyze the relationship between fine particulate matter and hospital daily outpatients with pediatric respiratory diseases in Shijiazhuang. Methods The data of meteorology, air pollution and the daily outpatients with pediatric respiratory diseases were collected during 2014-2016 in Shijiazhuang. Generalized additive model (GAM) extended Poisson distribution was used to examine the relationship between fine particulate matter and hospital outpatients with pediatric respiratory diseases in Shijiazhuang. According to the exposure-response relationship curve, piecewise linear regression was used for risk analysis. Results During the study period, the average annual concentration of PM_2.5 in Shijiazhuang was 104.93 μg/m³ and the average number of daily hospital outpatients was 690 to the pediatric respiratory diseases. The exposure-response relationship suggested a nonlinear between PM_2.5 and daily hospital outpatient visits. A larger increase in daily hospital outpatient visits was observed at lower concentration of PM_2.5. An increase of 10 μg/m³ of PM_2.5 (lag1)was significantly related to hospital outpatients with respiratory diseases and could increase the excess risk of 0.26%(0.14%-0.38%). By moving average concentration analysis, there was a cumulative lag effect between PM_2.5 concentrations pediatric respiratory visits. The highest influence between PM_2.5 and accumulative effects for pediatric respiratory diseases visits was occurred in lag 0-7. The analysis of multiple pollutants model showed that the effect of PM_2.5 on the outpatient respiratory diseases decreased when only SO₂ was introduced, and it was statistically significant. But there was no statistical significance when introducing other pollutants(all P>0.05). Conclusion The PM_2.5 in Shijiazhuang may lead to the increase in hospital outpatients with pediatric respiratory diseases.