Investigation of Indoor Air Quality in Public Primary Schools in Abeokuta, Ogun State

Children spend significant portions of their day in school environments, making indoor air quality a critical component of their overall health and cognitive performance. This study investigated indoor air quality conditions in ten public primary schools in Abeokuta, Ogun State, South West Nigeria. Carbon dioxide, carbon monoxide, particulate matter (PM2.5 and PM10), and total volatile organic compounds were measured using calibrated portable monitoring devices during school hours across wet and dry seasons. Structural and ventilation assessments were also conducted using an observational checklist. Carbon dioxide levels exceeded the 1000 ppm guideline in forty percent of monitored classrooms during peak occupancy hours, indicating inadequate ventilation. Particulate matter concentrations were significantly elevated in classrooms adjacent to unpaved playgrounds and in schools located near major roads. Seventy percent of classrooms had insufficient cross-ventilation due to blocked or broken windows. A self-administered symptom questionnaire completed by 480 pupils revealed that headache, eye irritation, and nasal congestion were commonly reported complaints correlated with poor air quality zones. The study found a significant negative correlation between ventilation adequacy and CO2 levels. Recommendations include renovation of classroom ventilation systems, adoption of dust suppression measures in school compounds, and establishment of routine air quality monitoring protocols by the Ogun State Ministry of Education. Keywords: indoor air quality, schools, carbon dioxide, ventilation, Abeokuta.