Evaluating Indoor Air Quality in Residential Environments: A Study of PM 2.5 and CO 2 Dynamics Using Low-Cost Sensors.

Indoor air quality (IAQ) poses a significant public health concern, and exposures to high levels of fine particulate matter (PM_2.5) and carbon dioxide (CO₂) could have detrimental health impacts. This study focused on assessing the indoor air pollutants in a residential house located in the town of Mission, Hidalgo County, South Texas, USA. The PM_2.5 and CO₂ were monitored indoors: the kitchen and the bedroom. This investigation also aimed to elucidate the effects of household activities such as cooking and human occupancy on these pollutants. Low-cost sensors (LCSs) from TSI AirAssure™ were used in this study. They were deployed within the breathing zone at approximately 1.5 m above the ground. Calibration of the low-cost sensors against Federal Equivalent Method (FEM) instruments was undertaken using a multiple linear regression method (MLR) model to improve the data accuracy. The indoor PM_2.5 levels were significantly influenced by cooking activities, with the peak PM_2.5 concentrations reaching up to 118.45 μg/m³. The CO₂ levels in the bedroom increased during the occupant's sleeping period, reaching as high as 1149.73 ppm. The health risk assessment was assessed through toxicity potential (TP) calculations for the PM_2.5 concentrations. TP values of 0.21 and 0.20 were obtained in the kitchen and bedroom, respectively. The TP values were below the health hazard threshold (i.e., TP < 1). These low TP values could be attributed to the use of electric stoves and efficient ventilation systems. This research highlights the effectiveness of low-cost sensors for continuous IAQ monitoring and helps promote better awareness of and necessary interventions for salubrious indoor microenvironments. [ABSTRACT FROM AUTHOR]