Associations Between Daily PM2.5 Exposure and Respiratory Symptoms in Thai Adolescents: Evidence from Nonthaburi Province

Air pollution remains a critical public health concern, especially for adolescents in densely populated urban areas. This cross-sectional study investigated the relationship between daily PM2.5 exposure and self-reported respiratory symptoms among 132 high school students in Nonthaburi Province, Thailand. Over a two-month period (January–February 2025), daily PM2.5 data were retrieved from government monitoring stations, while students completed daily online symptom surveys. During the study period, the mean PM2.5 concentration was 36.2 µg/m³, more than double the World Health Organization’s recommended limit of 15 µg/m³. A notable increase in symptom prevalence, 27.6% higher on days exceeding 40 µg/m³ compared to days at or below 25 µg/m³, was observed. Logistic regression analysis further revealed that each 10 µg/m³ increase in PM2.5 was associated with a 52% higher likelihood of respiratory symptoms (OR = 1.52, 95% CI: 1.26–1.79, p < 0.001).These findings highlight the acute impact of short-term air pollution exposure on adolescent health and emphasize the need for school-based air quality monitoring, preventive education, and evidence-driven environmental policy to reduce exposure and safeguard student well-being in high-risk urban settings.