The Relationship Between Seasonal Variations, PM2.5 Exposure, and Asthma Exacerbations in Children at Debaratana Nakhon ratchasima Hospital

Abstract

     This study was investigate to the relationship between seasonal variations and exposure levels of fine particulate matter less than 2.5 micrometers in diameter (PM₂.₅) on asthma exacerbations among pediatric patients admitted to Debaratana Nakhon ratchasima Hospital. This study employed a retrospective time-series design using data of pediatric patients under 15 years of age diagnosed with asthma (ICD-10: J45–J46), totaling 479 cases, and environmental data obtained from air quality monitoring stations of the Pollution Control Department between January 2020 and December 2024.

     Results: The incidence of asthma exacerbations among children was highest during the winter and rainy seasons, particularly from December to February, during which mean PM₂.₅ concentrations exceeded the World Health Organization (WHO) guideline on multiple consecutive days. After adjustment for temporal factors, both the rainy and winter seasons were significantly associated with an increased incidence of asthma exacerbations compared with the summer season (rainy season: incidence rate ratio [IRR] = 1.26, 95% confidence interval [CI] = 1.07–1.48, p = 0.005; winter season: IRR = 1.18, 95% CI = 1.01–1.40, p = 0.041).Regarding air pollution exposure, among children aged <5 years, same-day PM₂.₅ concentrations were significantly associated with hospital admission (odds ratio [OR] = 1.05, 95% CI = 1.00–1.09, p = 0.032), whereas no significant association was observed among children aged 5–15 years (p > 0.05). Multivariable logistic regression analysis further demonstrated that PM₂.₅ concentrations averaged over the preceding 3 days (3-day lag) were positively associated with moderate-to-severe asthma exacerbations in pediatric patients (adjusted OR = 1.03, 95% CI = 1.00–1.06, p = 0.040)