Integrating Fixed Monitoring Systems with Low-Cost Sensors to Create High-Resolution Air Quality Maps for the Northern China Plain Region

Abstract

To address and remediate severe particulate matter (PM) pollution in the North China Plain (NCP), many studies have traced pollution sources by using fixed air quality monitoring stations. However, these fixed monitors have high maintenance costs that make it economically infeasible to construct spatially dense networks for air quality measurement. Alternatively, using satellite monitoring systems and a low-cost air quality sensor network can greatly increase the spatiotemporal resolution of the ground-level PM concentration data for a given region. This study comprehensively examines the performance of China's EPA monitoring stations (CN-EPA), low-cost PM sensor networks and satellite aerosol optical depth (AOD) measurements. The goal is to improve the spatiotemporal resolution of ground-level PM concentration data for Xinxiang, a typical industrial city in the NCP. The inferred results show that low-cost PM sensors demonstrate high linearity with CN-EPA data sets for PM 2.5 concentrations with an R 2 value of 0.82. The PM 2.5 concentration inferred from the AOD retrievals demonstrates a moderate correlation with fixed monitoring stations with an R 2 value of 0.53. To evaluate the impact of human activities on air pollution, four traditional Chinese festivals, Chinese New Year, Tomb Sweeping Day, Ghost Festival, and Moon Festival, are chosen to observe the PM distribution in Xinxiang. Heat-maps of the ground-level PM 2.5 concentration reveal pollution hotspots in areas of high population density. Cross-validation is employed to evaluate the accuracy of the created pollution maps. The results demonstrate that pollution maps that were interpolated from data measured by CN-EPA data sets have the smallest root mean squared error (RMSE). Finally, our results show that low-cost PM sensor data can be integrated with traditional fixed air quality measurements to provide more detailed information about emission sources on pollution maps in urban and rural areas.

Assessment of Aerosol Persistence in ICUs via Low-cost Sensor Network and Zonal Models

“…[30,[35][36][37][38][39][40][41] These reports show that low-cost sensors yield usable data when calibrated against research-grade reference instruments. [28,42,43] The sensor networks have the potential to provide high spatial and temporal resolution, identifying pollution sources and hotspots, which in turn can lead to the development of intervention strategies for exposure assessment and intervention strategies for susceptible individuals. [44] Data can be fitted to a regression model when analyzing large data sets from [45] An essential factor in the data analysis to simplify or condense the data is to aggregate data from sensors providing that the specifics of the data (such as the locations of the sensor nodes) are not left out.…”

“…[43, 48-54] These reports show that low-cost sensors yield usable data when calibrated against research-grade reference instruments. [41, 55, 56]…”

“…Recent advancements in low-cost particulate matter (PM) sensors led to their extensive use in various applications, such as air quality (AQ) in indoor environments [28][29][30][31][32][33] and outdoor [34][35][36][37][38], including large scale deployments [39][40][41][42] by academic researchers and citizen scientists.…”

“…[43,[48][49][50][51][52][53][54] These reports show that low-cost sensors yield usable data when calibrated against research-grade reference instruments. [41,55,56] The sensor networks have the potential to provide high spatial and temporal resolution, identifying pollution sources and hotspots, which in turn can lead to the development of intervention strategies for exposure assessment and intervention strategies for susceptible individuals. [57] Data can be fitted to a regression model when analyzing large data sets from such networks.…”

Mario Molina Memorial Special Issue

“…47 Van Rooy et al report observations of how VOC levels changed during the first months of the COVID-19 pandemic. 48,49 Next-generation approaches are presented for monitoring air pollution using low-cost sensors in Ghana 50 and China, 51 and a new aerosol chemical speciation monitor mass spectrometry system was demonstrated in Atlanta, GA. 52 An airborne solar occultation flux instrument measured gases in plumes resulting from biomass burning, which is a major pollution source globally. 53 Price et al turned the power of atmospheric mass spectrometry analysis indoors to study gas-phase species and their reactivity in a museum setting.…”