Indoor Air Quality in University Libraries and Laboratories and Determinants of Perceived Respiratory and Allergic Symptoms among Students

Abstract

University indoor environments directly govern student well-being, yet empirical assessments linking specific microclimates to combined domestic and clinical health vectors remain sparse. We evaluated institutional indoor air quality (IAQ) across critical learning spaces at a major Nigerian tertiary institution while isolating how individual clinical histories and household exposure habits independently drive occupant health outcomes. Over eight consecutive weeks, we systematically logged five core IAQ parameters—particulate matter, carbon dioxide (CO2), formaldehyde (HCHO), ambient temperature, and relative humidity—across high-occupancy library zones and departmental science laboratories. To contextualise these environmental metrics, we simultaneously surveyed 140 student occupants utilising these monitored zones. This instrument captured self-reported respiratory symptoms alongside each participant's clinical baseline and daily domestic environmental exposures. Morning PM2.5 peaked in the SLT Pharm Lab (24.1 ± 14.1 µg/m³), exceeding the WHO limit (15 µg/m³) across nearly all the sampled areas. Measured relative humidity (69.1%–78.3%) and temperature (24.6°C–32.6°C) significantly exceeded standard ASHRAE 55 indoor comfort thresholds (30%–60% RH; 20.0°C–26.7°C), while CO₂ concentrations were around the 400 ppm level. The most common symptoms overall were frequent sneezing (29.3%) and a runny/stuffy nose (22.9%), while persistent coughing (15.0%) was the most common respiratory symptom. Preexisting respiratory conditions significantly increased the risk of persistent coughing (AOR = 8.73), shortness of breath (AOR = 14.87), and wheezing (AOR = 12.65) in multivariate regression analyses. Also, having a smoker in the home significantly increased the odds of wheezing (AOR = 20.24), while cleaning your home every day increased the odds of coughing (AOR = 3.46). There were significant microclimatic and particulate stressors present in the institutional microenvironments. The multivariate models, however, showed that students’ respiratory symptoms were significantly associated with clinical vulnerabilities and domestic exposures (such as preexisting conditions, and smoker cohabitation) rather than with the IAQ parameters in the institution, which were described.