Aerosol Measurement Degradation in Low-Cost Particle Sensors Using Laboratory Calibration and Field Validation

Increasing concern over air pollution has led to the development of low-cost sensors suitable for wide-scale deployment and use by citizen scientists. This project investigated the AirU low-cost particle sensor using two methods: (1) a comparison of pre- and post-deployment calibration equations for 24 devices following use in a field study, and (2) an in-home comparison between 3 AirUs and a reference instrument, the GRIMM 1.109. While differences (and therefore some sensor degradation) were found in the pre- and post-calibration equation comparison, absolute value changes were small and unlikely to affect the quality of results. Comparison tests found that while the AirU did tend to underestimate minimum and overestimate maximum concentrations of particulate matter, similar to 88% of results fell within +/- 1 mu g/m(3) of the GRIMM. While these tests confirm that low-cost sensors such as the AirU do experience some sensor degradation over multiple months of use, they remain a valuable tool for exposure assessment studies. Further work is needed to examine AirU performance in different environments for a comprehensive survey of capability, as well as to determine the source of sensor degradation.

Automated summary

Growing concern about air pollution has prompted the development of low-cost sensors for widespread use by citizen scientists. This study examined the AirU low-cost particle sensor using two approaches: comparing calibration equations before and after deployment in a field study, and comparing the AirU with a reference instrument. While some sensor degradation was observed, the impact on results was minimal, and the majority of measurements were within an acceptable range. These findings demonstrate that low-cost sensors like the AirU are still valuable for exposure assessment studies but further research is needed to understand their performance in different environments.