Revealing Nighttime Construction-related Activities from a Distributed Air Quality Sensor Network

Abstract

82 pagesCoarse particulate matter (PMc) refers to aerosol particles between 2.5 and 10 μm in diameter. Exposure to ambient PMc has been associated with adverse health effects such as cardiovascular diseases and respiratory mortality. In this study, we analyzed the spatial and temporal patterns of PMc levels in a 165-node PM monitoring network in Xi’an, China. We employed a technique called network analysis, focusing on peer-to-peer comparison within the network. The network analysis revealed that the highest PMc concentrations in the city occurred during late night and early morning. Through further analysis using satellite-based aerial imagery and data mining of internet resources, we confirmed with high confidence that the construction-related emission sources, both at the construction sites and from traffic transporting construction materials and debris, are a key contributor. It could be found that both local policies and construction practices incentivized construction contractors to implement earthwork at nighttime, leading to distinct peak PMc concentrations from late night to early morning, which often triggered both noise and air pollution complaints from residents. Our work demonstrated the potential of utilizing air quality monitoring networks for construction-related environmental monitoring and enforcement. Based on our findings, we also recommend that policymakers re-assess construction-related policies by considering the trade-offs among efficiency, safety, air quality, and noise