Measurement of Carbon Dioxide and Volatile Organic Compounds (VOCs) in Relation to Sick Building Syndrome Among Users of the Learning Space at Ratchasima Khunakon Building, Suranaree University of Technology

Background: Indoor air quality (IAQ) significantly affects human health, particularly in confined public spaces such as educational facilities. Elevated levels of carbon dioxide (CO2) and total volatile organic compounds (TVOCs) have been associated with Sick Building Syndrome (SBS), a condition characterized by acute health and comfort effects linked to time spent indoors. Objectives: This study aims to assess CO2 and TVOCs concentrations in Learning Space rooms on the 1st and 5th floors of the Ratchasima Khunakon Building, Suranaree University of Technology, and to evaluate their association with SBS symptoms and indoor environmental factors. Methods: A cross-sectional descriptive study was conducted using real-time monitoring instruments and SBS symptom questionnaires. A total of 131 valid responses were analyzed. CO2 and TVOCs data were compared against Thailand’s 2022 IAQ standards. Correlations with temperature, relative humidity, and air velocity were also assessed. Results: CO2 concentrations were not significantly different between floors, whereas TVOCs levels showed a statistically significant variation (p < 0.05). SBS symptoms were reported by 8.39% of participants, with neurological symptoms and insomnia being most common. Significant associations were found between pollutant levels and SBS symptoms, except for drowsiness on the 5th floor. TVOCs were positively correlated with temperature and humidity, while CO2 showed no such correlation. Conclusion: Indoor pollutant levels, particularly TVOCs, may contribute to SBS in learning environments. Environmental controls are essential for improving IAQ and protecting occupant health in educational buildings.