Objective To quantify the acute health effects of short-term exposure to fine particulate matter (PM_2.5) on pediatric respiratory disease outpatient visits in Shenyang, China, and to provide evidence for developing health protection strategies against air pollution for children in heavily industrial cities.

Methods Outpatient visit data for pediatric respiratory diseases, specifically acute upper and lower respiratory infections, were collected from 2022 to 2024 from two general hospitals representing the main urban area of Shenyang, along with contemporaneous air pollution and meteorological measurements. A quasi-Poisson generalized additive model (GAM) was used to assess the impact of short-term PM_2.5 exposure on pediatric respiratory disease outpatient visits in Shenyang.

Results From 2022 to 2024, the median daily outpatient visits for pediatric respiratory diseases and their main subtypes (acute upper and lower respiratory infections) in Shenyang were 14, 4, and 3 visits/day, respectively. In the single-day lag effect analysis, for each 10 μg/m³ increase in PM_2.5 concentration at lag 0 d, the excess risks (ER)and 95% confidence intervals(CI) of outpatient visits for respiratory diseases and their subtypes (acute upper and lower respiratory infections) were 1.59% (0.17%, 3.03%), 3.37% (0.85%, 5.95%), and 2.55% (0.29%, 4.85%), respectively. In the cumulative lag effect analysis, the risk of outpatient visits for acute upper respiratory infections increased by 5.60% (95% CI: 1.29%-9.82%) at lag 07 d. The impact of PM_2.5 exposure on respiratory disease outpatient visits decreased after adjusting for O₃-8 h in the two-pollutant model.

Conclusion PM_2.5 exposure is associated with an increase in pediatric respiratory disease outpatient visits, primarily acute effects. Therefore, it is recommended to strengthen health protection for children during heavily polluted weather.