Guidelines for IAQ monitoring with low-cost air sensors in homes with asthmatic patients

Indoor air quality (IAQ) is a crucial determinant of health, which is of particular concern for low-income Black children, who are disproportionately exposed to asthma triggers in their indoor housing environment and have higher rates of asthma and poorer outcomes from the disease, indicating an environmental justice issue. However, guidelines for IAQ data collection vary between organizations, making assessments and comparisons difficult. This study consolidates recommended practices into one cohesive set of guidelines for monitoring IAQ. It outlines a structured approach for defining IAQ sampling objectives, identifying the most appropriate low-cost air sensors, determining optimal sensor placement in homes, developing data collection and analysis, and presenting and interpreting results. With indoor PM_2.5 as a case study, the guidelines were used to determine sampling duration, analysis, and quality assurance in five households with pediatric asthma patients. The metrics illustrate PM_2.5 concentration by the 90th percentile (with average concentration level from 4 to 109 μg/m³), daily average minutes of PM_2.5 concentration exceeding recommended exposure limits of 0-134 min, daily average PM_2.5 concentration of 1.8-82 μg/m³, and significant temporal variation across households. This study highlights the significance of employing low-cost air sensors to provide real-time notifications of IAQ, along with simplified monitoring guidelines for researchers, healthcare providers, and parents working to improve IAQ for households with asthmatic children, potentially reducing the frequency and severity of asthma attacks. The low-cost sensors and resulting metrics can direct interventions effectively and provide a basis for determining the efficacy of environment-based air quality interventions.<i>Implications</i>: People spend much of their time indoors, especially at home, making indoor air quality (IAQ) monitoring crucial for guiding actions that reduce asthma exacerbations, particularly among low-income households. Although low-cost air sensors are being widely used for real-time IAQ monitoring, most existing guidelines focus on occupational settings rather than residential environments, making implementation difficult. This study develops comprehensive and unified guidelines for deploying low-cost sensors for real-time IAQ monitoring in residential settings. A case study utilizing the developed guideline in this study was applied to demonstrate and evaluate PM_2.5 concentration levels in some low-income residential homes in Southeastern Louisiana.