Urban configuration and PM2.5 concentrations: Evidence from 330 Chinese cities

Preventing high concentrations of fine particulate (PM2.5) to realize the goal of sustainable development is becoming a challenge for rapidly urbanized cities. Increasing vehicle emission due to inefficient urban form is thought to be the main cause of traffic congestion and increased PM2.5 concentrations. Previous efforts attributing PM2.5 concentrations to urban forms are yet to reach consistent conclusions on practical environmental protection strategies. In this study, we considered urban compositions and their spatial configuration to propose a new measurement-urban configuration-and document the effects of urban configuration on PM2.5 concentrations. Using 330 Chinese cities as our sample, we found that the areas of two types of urban facilities, namely, residence and industry, are positively related to PM2.5 concentrations, and the area of public service facilities is negatively related to PM2.5 concentrations. Regarding the spatial configuration of different urban compositions, we documented that residence-industry accessibility is a key factor of PM2.5 concentrations and plays a more important role than the residence-commerce accessibility. We also compared the influence of two accessibility indices (distance-and gravity-based accessibilities) and further found that the effect of reducing the residence-industry distance is more remarkable than the effect of increasing residential or industrial area on reducing PM2.5 concentrations. Our results indicate that the key to reaching sustainable urban expansion is to synchronize urban constructions with spatial configuration optimization. For Chinese cities, a 7.52% increase in residence area requires at least 1% decrease in the average residence-industry distance to eliminate the incremental effects of newly constructed residential region on PM2.5 concentrations. This study casts new light on the relationship between urban configuration and PM2.5 concentration and provides decision makers practical and realistic approaches in realizing sustainable development goals.

Automated summary

Preventing high concentrations of PM2.5 is a challenge for rapidly urbanized cities. This study examines the effects of urban configuration on PM2.5 concentrations and proposes practical approaches for sustainable development. The results suggest that the areas of residence and industry are positively related to PM2.5 concentrations, while the area of public service facilities is negatively related. The accessibility between residence and industry plays a key role in determining PM2.5 concentrations. The study provides insights for decision makers in optimizing urban constructions and achieving sustainable development goals.