INDOOR AIR QUALITY IN COMPUTER-BASED EXAMINATION HALLS: ASSESSING STUDENT-GENERATED PM₂.₅, CO₂, AND VOCS FOR RISK EVALUATION AND MITIGATION
Article Sidebar
Main Article Content
Abstract
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.
Downloads
Article Details
Section
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
References
[1] Sadrizadeh, S., Yao, R., Yuan, F., Awbi, H., Bahnfleth, W., Bi, Y., Cao, G., Croitoru, C., de Dear, R., Haghighat, F., Kumar, P., Malayeri, M., Nasiri, F., Ruud, M., Sadeghian, P., Wargocki, P., Xiong, J., Yu, W., & Li, B. (2022). Indoor air quality and health in schools: A critical review for developing the roadmap for the future school environment. Journal of Building Engineering, 57, 104908. https://doi.org/10.1016/j.jobe.2022.104908
[2] Ezeamii, V. C., Egbuchiem, A. N., Obianyo, C. M., et al. (2025, May 1). Air quality monitoring in schools: Evaluating the effects of ventilation improvements on cognitive performance and childhood asthma. Cureus, 17(5), e83306. https://doi.org/10.7759/cureus.83306
[3] Deng, Z., Dong, B., Guo, X., & Zhang, J. (2024). Impact of indoor air quality and multi-domain factors on human productivity and physiological responses: A comprehensive review. Indoor Air, 2024(1), 5584960. https://doi.org/10.1155/2024/5584960
[4] Da Silva, L. F. (2024). Optimizing Indoor Air Quality and Thermal Comfort in Educational Classrooms: A Multicriteria Investment Strategy for Ventilation Infrastructure Prioritization [Master's thesis, UPC, Escola Tècnica Superior d'Enginyeria de Camins, Canals i Ports de Barcelona]. Retrieved from http://hdl.handle.net/2117/421426
[5] Ezeamii, V. C., Egbuchiem, A. N., Obianyo, C. M., Nwoke, P., & Okwuonu, L. (2025). Air quality monitoring in schools: Evaluating the effects of ventilation improvements on cognitive performance and childhood asthma. Cureus, 17(5), e83306. https://doi.org/10.7759/cureus.83306
[6] Cheeseman, K. (2024). The impacts of environmental conditions on health and education. (K4DD Rapid Evidence Review 73). Institute of Development Studies. https://doi.org/10.19088/K4DD.2024.040
[7] Salthammer, T., & Morrison, G. C. (2022). Temperature and indoor environments. Indoor Air, 32(5), e13022. https://doi.org/10.1111/ina.13022
[8] Jansen-van Vuuren, R. D., Naficy, S., Ramezani, M., Cunningham, M., & Jessop, P. (2023). CO$_{2}$-responsive gels. Chemical Society Reviews, 52(10), 3470–3542. https://doi.org/10.1039/D5CS00479A
[9] Sonne, C., Xia, C., Dadvand, P., Targino, A. C., & Lam, S. S. (2022). Indoor volatile and semi-volatile organic toxic compounds: Need for global action. Journal of Building Engineering, 62, 105344. https://doi.org/10.1016/j.jobe.2022.105344
[10] Sonne, C., Xia, C., Dadvand, P., Targino, A. C., & Lam, S. S. (2022). Indoor volatile and semi-volatile organic toxic compounds: Need for global action. Journal of Building Engineering, 62, 105344. https://doi.org/10.1016/j.jobe.2022.105344
[11] Li, S., Meng, X., Zhai, W., Yu, X., & Zhang, S. (2024). Integrated assessment of indoor and outdoor airborne microplastics in a northern Chinese university campus: Pollution characteristics, meteorological drivers, and child-specific exposure risks. SSRN. https://ssrn.com/abstract=5252472
[12] Chatzidiakou, L., Mumovic, D., & Summerfield, A. J. (2012). What do we know about indoor air quality in school classrooms? A critical review of the literature. Intelligent Buildings International, 4(4), 228–259. https://doi.org/10.1080/17508975.2012.725530
[13] Johnson, D. L., Lynch, R. A., Floyd, E. L., Wang, J., & Bartels, J. N. (2018). Indoor air quality in classrooms: Environmental measures and effective ventilation rate modeling in urban elementary schools. Building and Environment, 136, 185–197. https://doi.org/10.1016/j.buildenv.2018.03.040
[14] Jung, J. S., Park, D. S., Jeon, H. J., Song, H. S., & Lee, M. J. (2015). A study of indoor air quality of school classrooms. Journal of the Korea Academia-Industrial Cooperation Society, 16(5), 3643–3652. https://doi.org/10.5762/KAIS.2015.16.5.3643
[15] Tran, M. T., Wei, W., Dassonville, C., Martinsons, C., Ducruet, P., Mandin, C., Héquet, V., & Wargocki, P. (2023). Review of parameters measured to characterize classrooms’ indoor environmental quality. Buildings, 13(2), 433. https://doi.org/10.3390/buildings13020433
[16] Zhang, X., Zhao, C., Zhang, T., Xie, J., Liu, J., & Zhang, N. (2023). Association of indoor temperature and air quality in classrooms based on field and intervention measurements. Building and Environment, 229, 109925. https://doi.org/10.1016/j.buildenv.2022.109925
[17] Sadrizadeh, S., Yao, R., Yuan, F., Awbi, H., Bahnfleth, W., Bi, Y., Cao, G., Croitoru, C., de Dear, R., Haghighat, F., Kumar, P., Malayeri, M., Nasiri, F., Ruud, M., Sadeghian, P., Wargocki, P., Xiong, J., Yu, W., & Li, B. (2022). Indoor air quality and health in schools: A critical review for developing the roadmap for the future school environment. Journal of Building Engineering, 57, 104908. https://doi.org/10.1016/j.jobe.2022.104908
[18] Nicolaou, L., & Checkley, W. (2021). Inequities in air pollution exposure and gaps in air quality monitoring. Journal of Allergy and Clinical Immunology, 148(1), 64–66. https://doi.org/10.1016/j.jaci.2021.04.014
[19] Adekoya, A., Tyagi, S. K., Duru, C. N., Satia, I., Paudyal, V., & Kurmi, O. P. (2022). Effects of household air pollution (HAP) on cardiovascular diseases in low- and middle-income countries (LMICs): A systematic review and meta-analysis. International Journal of Environmental Research and Public Health, 19(15), 9298. https://doi.org/10.3390/ijerph19159298
[20] Gulia, S., Khanna, I., Shukla, K., & Khare, M. (2020). Ambient air pollutant monitoring and analysis protocol for low and middle income countries: An element of comprehensive urban air quality management framework. Atmospheric Environment, 222, 117120. https://doi.org/10.1016/j.atmosenv.2019.117120
[21] Chandra, M., Rai, C. B., Kumari, N., Sandhu, V. K., Chandra, K., Krishna, M., ... Oudin, A. (2022). Air pollution and cognitive impairment across the life course in humans: A systematic review with specific focus on income level of study area. International Journal of Environmental Research and Public Health, 19(3), 1405. https://doi.org/10.3390/ijerph19031405
[22] Päivärinta, R. (2025). Indoor air quality in European school buildings and approach of citizen science [Master's thesis, Aalto University]. Retrieved from https://aaltodoc.aalto.fi/server/api/core/bitstreams/64ba7ba9-1930-4ac1-a60b-ad9030683a3b/content
[23] Peters, T., & Zhen, C. (2024). Evaluating indoor air quality monitoring devices for healthy homes. Buildings, 14(1), 102. https://doi.org/10.3390/buildings14010102
[24] Airthings. (n.d.). AIRTHINGS Device Database. Retrieved July 1, 2025, from https://device.report/airthings
[25] Airthings. (n.d.). View Plus - smart indoor air quality monitor. Retrieved July 1, 2025, from https://www.airthings.com/en/view-plus
[26] Geiger, A., & Cooper, J. (2010, December 3). Overview of airborne metals regulations, exposure limits, health effects, and contemporary research [Draft]. Environmental Protection Agency, Portland.
[27] Taqwa, M. Z., & Tharavathy, N. C. (2025). A Study on Air Pollution Levels in Kabul City, Afghanistan. INTERNATIONAL JOURNAL OF PLANT AND ENVIRONMENT, 11(01), 68-76. https://doi.org/10.18811/ijpen.v11i01.08
[28] Patwari, J. M., Narkhede, R. K., & Cholkar, N. B. (2025). Air Quality in Udgir, Maharashtra, November 2024: MPCB Limit Exceedances during Diwali and Election Activities. International Journal of Research Studies on Environment, Earth, and Allied Sciences, 2(1), 92–95. https://doi.org/10.5281/zenodo.15089378
[29] Persily, A. (2020, November). Quit blaming ASHRAE Standard 62.1 for 1000 ppm CO2. Paper presented at the 16th Conference of the International Society of Indoor Air Quality & Climate (INDOOR AIR 2020), Online. https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929997
[30] Nirlo, E. L., Crain, N., Corsi, R. L., & Siegel, J. A. (2015). Field evaluation of five volatile organic compound measurement techniques: Implications for green building decision making. Science and Technology for the Built Environment, 21(1), 67–79. https://doi.org/10.1080/10789669.2014.969172
[31] Du, L., Wang, Y., Wu, Z., Hou, C., Mao, H., Li, T., & Nie, X. (2019). PM2. 5-bound toxic elements in an Urban City in East China: concentrations, sources, and health risks. International Journal of Environmental Research and Public Health, 16(1), 164. https://doi.org/10.3390/ijerph16010164
[32] Emert, A. D., Griffis-Kyle, K., Portillo-Quintero, C., & Smith, P. N. (2024). USEPA CALPUFF validation and dispersion modeling of beef cattle feedlot PM10 and PM2. 5 emissions factors. Atmospheric Environment, 316, 120189. https://doi.org/10.1016/j.atmosenv.2023.120189
[33] Balakrishnan, V. S. (2025). Clean air, climate targets, and respiratory health in Europe. The Lancet Respiratory Medicine, 13(2), e12–e13. https://doi.org/10.1016/S2213-2600(24)00403-X
[34] Telejko, M., & Zender-Świercz, E. (2017). An attempt to improve air quality in primary schools. In 10th International Conference “Environmental Engineering” (ICEE-2017). https://etalpykla.vilniustech.lt/handle/123456789/154885
[35] Stumm, R. E. (2022). Revisiting the 1,000 ppm CO2 Limit. ASHRAE Journal, 64(6), 14. https://openurl.ebsco.com/EPDB%3Agcd%3A6%3A21545206/detailv2?sid=ebsco%3Aplink%3Ascholar&id=ebsco%3Agcd%3A157174532&crl=c&link_origin=scholar.google.com
[36] Cao, X., Li, P., Zhang, J., & Pang, L. (2022). Associations of Human Cognitive Abilities with Elevated Carbon Dioxide Concentrations in an Enclosed Chamber. Atmosphere, 13(6), 891. https://doi.org/10.3390/atmos13060891
[37] U.S. Green Building Council. (2019). LEED v4.1 Residential BD+C Multifamily Homes. U.S. Green Building Council. http://www.spaingbc.org/files/leed_v4.1/LEED_v4_1_RESIDENCIAL_MULTIFAMILIAR_SISTEMA_CLASIFICACION.pdf
[38] Babich, F., Torriani, G., Corona, J., & Lara-Ibeas, I. (2023). Comparison of indoor air quality and thermal comfort standards and variations in exceedance for school buildings. Journal of Building Engineering, 71, 106405. https://doi.org/10.1016/j.jobe.2023.106405
[39] Nibagwire, D., Ana, G. R. E. E., Kalisa, E., et al. (2025). Exposure patterns of PM2.5 and CO concentrations in residential and commercial buildings: Factors influencing indoor air quality. Air Quality, Atmosphere & Health. https://doi.org/10.1007/s11869-025-01740-5
[40] Chepaitis, P. S., Zhang, Q., Kalafut, D., Waddey, T., Wilson, M. J., & Black, M. (2024). The Effect of Moderate Temperature Rise on Emitted Chemicals from Modern Building Materials. Buildings, 14(11), 3683. https://doi.org/10.3390/buildings14113683
[41] Fromme, H. (2023). Indoor air quality: Occurrence and health effects of contaminants. Springer Nature. https://doi.org/10.1007/978-3-031-40078-0
[42] Weschler, C. J., & Carslaw, N. (2018). Indoor chemistry. Environmental Science & Technology, 52(5), 2419–2428. https://doi.org/10.1021/acs.est.7b06387