Application of the application of the compact and useful PM2.5 instrument with gas sensors (CUPI-G) for high temporal and spatial resolution monitoring with weather factor integration

Abstract

Low-cost air pollution sensors have emerged as promising tools for monitoring air quality with high temporal and spatial resolution, especially in suburban areas of developed countries that are transitioning towards urbanization where air quality can vary significantly. The motivation for this research is to develop affordable, portable air quality sensors for suburban areas with limited access to expensive traditional monitoring equipment. This study utilized the Compact and Useful PM2.5 Instrument with gas sensors (CUPI-G), a low-cost device designed to monitor PM2.5, CO, NO, NO2, and Ox (from which O3 was calculated). The high temporal resolution data in Kyoto, Japan, averaged over 31 s, revealed seasonal variations in pollutant levels. O3 and CO concentrations were highest in summer, at 29.28 ppb and 95.33 ppb, respectively, and lowest in autumn, with values of 20.03 ppb for O3 and 81.18 ppb for CO. Conversely, PM2.5 levels were lowest in summer (4.95 μg/m3) and highest in autumn (5.08 μg/m3). Nearly a month of spatial analysis in three different areas (defined as residential, road, and educational) showed PM2.5 concentrations were highest in residential areas, averaging hourly 21.53 μg/m3, while CO and O3 levels were elevated near roadways, with concentrations of 188.02 ppb, and 46.62 ppb, respectively. This research innovatively employed low-cost sensor technology to deliver high-resolution air quality data and demonstrated that wind speed and direction along with temperature were significant factors contributing to suburban air pollution, providing insights into potential pollution sources, and meteorological risk factors for elevated pollution levels.