Due to the adverse health effects of PM2.5 (particles with a diameter less than 2.5 μm), the national ambient air quality standards (NAAQS) for PM2.5 have been established in many countries. Ambient PM2.5 concentrations are monitored to determine compliance with the NAAQS, where beta attenuation monitors (BAMs) are widely used as a reference method. However, the high costs of installation and maintenance of BAMs result in difficulties in enhancing the spatial resolution of PM2.5 monitoring. In this context, low-cost PM2.5 sensors (LCSs) have been widely deployed for PM2.5 measurements. Despite their low cost and ease of installation, concerns regarding the data reliability of LCSs remain unresolved, necessitating further field research under various environmental conditions. In this study, we conducted a data comparability assessment between 125 LCSs and two BAMs over 12 months. Daily average PM2.5 concentrations measured by LCSs generally agreed with those from BAMs. However, when comparing hourly PM2.5 data, we found that the data comparability of LCSs against BAMs was lower than that of the daily average data, primarily influenced by ambient PM2.5 levels. Additionally, we found statistical differences in PM2.5 concentrations among six regions within the study area. This indicates that ambient PM2.5 levels can vary within a small area, supporting the necessity of monitoring PM2.5 on a small scale. Overall, the results of this study suggest that the sensors demonstrate both potential and limitations in PM2.5 monitoring. Therefore, to use LCSs for PM2.5 monitoring, it is necessary to appropriately select the averaging time and PM2.5 concentration ranges, considering local environmental conditions and the inherent characteristics of LCSs.
Keywords: Beta attenuation monitor; Intraclass correlation coefficient; PM2.5 sensor.
© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.