Work

Temperature-dependent association between ambient ozone exposure and allergic rhinitis-related outpatient visits: a time-stratified case-crossover study in Henan Province, China

Year: 2026

Type: article

Abstract: Background Ambient ozone (O 3 ) may adversely affect the upper airway, but whether temperature modifies its short-term association with outpatient visits for allergic rhinitis remains unclear. Methods We conducted a time-stratified case-crossover study of 43,418 outpatient visits for allergic rhinitis at a tertiary hospital in Henan, China, during April–October of 2013–2023. Daily O 3 , PM 2.5 , temperature, and relative humidity (RH) were assigned by residential address using gridded datasets and averaged over lag 0–1 day. Conditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) per 10 μg/m 3 increase in O 3 across the observed exposure distribution, adjusting for temperature, RH, and PM 2.5 . Temperature modification was assessed using an interaction term between O 3 and a natural cubic spline function of temperature. Results Each 10 μg/m 3 increase in O 3 was associated with a 1.2% increase in the odds of an outpatient visit for allergic rhinitis (OR = 1.012, 95% CI: 1.006–1.017). The largest age-specific estimate was observed among patients aged <18 years (OR = 1.030, 95% CI: 1.017–1.044). Temperature significantly modified the association (χ 2 = 31.2, P < 0.001), the OR for O 3 increased from 1.000 at the 25th percentile of temperature to 1.021 at the 75th percentile. Conclusion Short-term O 3 exposure was associated with higher odds of outpatient visits for allergic rhinitis, with larger estimates at higher temperatures and among patients aged <18 years.

Source: Frontiers in Public Health

DOI: 10.3389/fpubh.2026.1952329