Empowering Communities Through Data: Assessing Low-Cost Air Quality Monitors to Advance Environmental Health Equity in Greenville, North Carolina

Abstract

Introduction: Air quality remains one of the leadings causes of respiratory illnesses on a global scale. PM2.5 in particular, is a clear public health concern in areas with limited regulatory monitoring and vulnerable populations. It is critical that affordable air quality options be made available considering the limitations of traditional monitoring. This study assesses the air quality in Greenville, North Carolina while evaluating how AirBeam, Clarity, and Bluesky low-cost sensors perform in comparison to a ADR reference monitor and an EPA regulatory monitor. The goal was to determine if low-cost sensors could accurately reflect PM2.5 trends and support community-based air monitoring. Methods: Stationary low-cost sensors and a reference monitor were set up at the intersection of Greenville Boulevard and Charles Boulevard on tripods. A HOBO weather instrument was also co-located with sensors and reference monitor to assess atmospheric conditions. Data was recorded in hourly intervals on a daily basis from January through December 2024. Data was analyzed annually, biannually, and seasonally. The exclusion of missing and outlier values was applied to improve accuracy and consistency. Performance metrics that include R2, RMSE, slope, and intercept were measured to assess agreement with the reference instrument. Results: Results showed positive relationships between low-cost sensors and reference concentration readings. AirBeam provided the most consistent overall agreement with the reference monitor. Clarity produced the steepest slopes, highest intercepts, and higher RSME indicating stronger sensitivity and more variability. Bluesky recorded the lowest RMSE and the weakest correlations. Each sensor successfully identified major pollution events, including wildfire smoke days. Conclusion: The study demonstrates that low-cost sensors, when properly calibrated, provide dependable and affordable means for monitoring air quality data. This is highly important in underserved and rural areas where traditional air monitoring is limited or unavailable. Implementation of low-cost air monitoring devices offer many benefits and can be a practical method to strengthen environmental surveillance to protect public health.