Investigation of indoor air quality in university residences using low-cost sensors

Abstract

Exposure to air pollutants can cause serious adverse effects on human health; thus, indoor air quality (IAQ) is an important health and safety concern for occupants. A significant fraction of university students live in institution-managed residences. The length of time they spent in the residences, along with the negative impact of air pollutants on their health and academic performance, necessitate the need for continuous monitoring of IAQ in student residences. This study represents the first application of a low-cost sensors (LCS) network in university residences. Four major IAQ parameters (i.e., particulate matter (PM_2.5), carbon dioxide (CO₂), temperature, and relative humidity) were monitored in five residences in a Canadian university for five months. Questionnaires were used to investigate students' lifestyles and their relationship with air pollutants. The results of this study show that indoor activities, such as cooking and humidifier use, can generate indoor PM_2.5 with daily average concentrations higher than the maximum exposure limit recommended by the US Environmental Protection Agency. The study also found that the building ventilation behavior and outdoor temperature affected the indoor CO₂ and PM_2.5 concentrations. Additionally, a correlation between indoor and outdoor PM_2.5 concentrations indicated the impact of outdoor air on indoor air quality. Besides these scientific findings, this study demonstrated that spatiotemporally-resolved, personalized IAQ provided by LCS could benefit the controlling and mitigation of the risks associated with indoor air pollutant exposure. An LCS network can serve as an affordable strategy to monitor students' living environment on university campuses.