2024 Yes https://doi.org/10.1002/ejsc.12280 Moloney, Scarlett Europe Experimental Exposure Study Students Elementary (K-5) Particulate Matter (PM) Volatile Organic Compounds (VOCs) Respiratory symptoms Active travel Air quality Airway inflamation Children Exposure School routes Children’s walks near roads and in parks showed PM and VOC levels near WHO limits. FeNO declined similarly after both, reflecting normal exercise response. Findings suggest active school travel may not elevate airway inflammation risk in low-pollution areas.