Short-term effects of ambient ozone on pediatric pneumonia hospital admissions: a multi-city case-crossover study in China.

Huan WANG; Huan-Ling ZENG; Guo-Xing LI; Shuang ZHOU; Jin-Lang LYU; Qin LI; Guo-Shuang FENG; Hai-Jun WANG

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Short-term effects of ambient ozone on pediatric pneumonia hospital admissions: a multi-city case-crossover study in China.

Author: Huan WANG ¹ ; Huan-Ling ZENG ² ; Guo-Xing LI ³ ; Shuang ZHOU ⁴ ; Jin-Lang LYU ¹ ; Qin LI ¹ ; Guo-Shuang FENG ⁵ ; Hai-Jun WANG ¹
Author Information

1. Department of Maternal and Child Health, School of Public Health, Peking University, National Health Commission Key Laboratory of Reproductive Health.
2. Department of Oncology, Xiaolan People's Hospital of Zhongshan, the Fifth People's Hospital of Zhongshan.
3. Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University.
4. Climate, Air Quality Research Unit, School of Public Health and Preventive Medicine, Monash University.
5. Big Data Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health.
Publication Type:Journal Article
Keywords: Case-crossover study; Ozone; Pediatric pneumonia
MeSH: Humans; Ozone/analysis*; China/epidemiology*; Pneumonia/chemically induced*; Child, Preschool; Male; Female; Infant; Cross-Over Studies; Air Pollutants/analysis*; Hospitalization/statistics & numerical data*; Child; Cities/epidemiology*; Air Pollution/adverse effects*; Infant, Newborn; Environmental Exposure/adverse effects*
From:Environmental Health and Preventive Medicine 2025;30():75-75
CountryJapan
Language:English
Abstract: BACKGROUND:Children's respiratory health demonstrates particular sensitivity to air pollution. Existing evidence investigating the association between short-term ozone (O₃) exposure and childhood pneumonia remains insufficient and inconsistent, especially in low- and middle-income countries (LMICs).
METHOD:To provide more reliable and persuasive evidence, we implemented a multi-city, time-stratified case-crossover design with a large sample size, using data from seven representative children's hospitals across major geographical regions in China. To avoid the impact of the COVID-19 pandemic, individual-level medical records of inpatient children under 6 years of age diagnosed with pneumonia during 2016-2019 were collected. Conditional logistic regression models were fitted for each city, and city-specific estimates were pooled through a meta-analysis using a random-effects model.
RESULTS:In total, the study included 137,470 pediatric pneumonia hospital admissions. The highest pooled estimate for O₃ occurred at lag0-1, with a 10 µg/m³ increase in O₃ associated with a 1.57% (95% CI: 0.67%-2.48%) higher risk of pediatric pneumonia hospital admissions. Stratified analyses indicated that the effects of O₃ were robust across different sexes, age groups, and admission seasons. We also observed a statistically significant increase in risk associated with O₃ concentrations exceeding the World Health Organization Air Quality Guidelines (WHO-AQGs).
CONCLUSIONS:This study revealed a significant positive association between O₃ and pediatric pneumonia hospital admissions. Our findings substantially strengthen the evidence base for the adverse health impacts of O₃, underscoring the importance of O₃ pollution control and management in reducing the public health burden of pediatric pneumonia.