INDOOR AIR QUALITY IN COMPUTER-BASED EXAMINATION HALLS: ASSESSING STUDENT-GENERATED PM₂.₅, CO₂, AND VOCS FOR RISK EVALUATION AND MITIGATION

Computer-based examinations are vital for modern education, but poor indoor air quality (IAQ) in enclosed exam halls, especially in low- and middle-income countries (LMICs), can harm students' health and cognitive functions. This study investigates real-time changes in pollutants produced by students (PM₂.₅, CO₂, and total VOCs) during live exams at a Nigerian university, which exemplifies an LMIC setting with natural ventilation and high occupant density. Using cloud-connected Airthings View Plus monitors, we recorded pollutant levels during pre-exam, active exam, and post-exam phases. The results revealed notable IAQ decline: PM₂.₅ peaked at 26 µg/m³ (exceeding WHO 24-hour guidelines), CO₂ reached 1,682 ppm (68% above ASHRAE standards), and VOCs increased to 839 ppb (almost three times Health Canada’s limit). Elevated temperature (29°C) and humidity (73%) intensified pollutant persistence through hygroscopic particle growth and VOC volatilisation. Although pollutant levels remained below occupational hazard limits, frequent breaches of health guidelines highlight risks in poorly ventilated exam environments. This study underscores the need for affordable, immediate interventions such as improved ventilation schedules, reduced occupancy, and fragrance-free policies to minimise exposure. Our findings offer empirical evidence of IAQ concerns in LMIC academic settings and lay a foundation for future research on VOC composition and thermal comfort trade-offs. The work advocates for context-specific strategies over large infrastructure modifications, considering the resource limitations in LMICS.