Assessment of Indoor Particulate Matter Concentrations Across Different Residential Microenvironments Using Portable Low-Cost Sensors

Abstract

Indoor air quality is of great importance for human health as people spend a large part of their lives indoors. In this study, particulate matter (PM₁, PM₂.₅, and PM₁₀) concentrations were monitored in three residential microenvironments — the living room, the kitchen, and the bedroom — in a house in Ballari, Karnataka, India, using a low-cost portable air quality monitor. In addition, both the indoor temperature and the relative humidity were monitored to examine their effects on particulate matter concentrations. Hourly measurements were taken over 15 consecutive days (March–April 2025), with five days of monitoring in each microenvironment. A temporal analysis found short-term increases in particulate matter concentrations during periods of increased household activity. The relatively high PM levels in the living room were likely due to the ingress of outdoor dust, whereas the bedroom had comparatively lower and more stable concentrations. The results showed clear differences in particulate matter levels among the areas under investigation.