Assessment of traffic related air pollution effects on indoor air quality in educational buildings

This study assesses the impact of traffic-related air pollution (TRAP) on indoor air quality (IAQ) within a Riyadh school. The main objectives are to pinpoint factors influencing IAQ and to evaluate the effectiveness of existing ventilation and filtration systems. Air quality Egg sensors monitored nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter (PM1.0, PM2.5, PM10) levels both indoors and outdoors over 30 days. Findings revealed average indoor PM2.5 and PM10 concentrations of 14.09 µg/m3 and 18.15 µg/m3, respectively, while outdoor concentrations averaged 20.63 µg/m3 and 27.88 µg/m3. A strong positive correlation was observed between indoor and outdoor PM levels, with Spearman coefficients ranging from 0.81 to 0.94. Principal Component Analysis (PCA) indicated that particulate matter is the primary contributor to IAQ issues, followed by humidity and gases like NO2 and CO. Notably, indoor NO2 averaged 43.36 ppb, surpassing the outdoor average of 38.66 ppb, suggesting indoor sources and ventilation shortcomings. These results highlight the need for strategic school siting, enhanced HVAC systems, and routine IAQ monitoring. Recommendations emphasize locating schools away from major traffic areas and adopting advanced air purification technologies. Expanding research across schools could further clarify IAQ impacts, supporting healthier environments for children.