Examining the impact of polycentric urban form on air pollution: evidence from China

Numerous studies on megacities have reported less air pollution in polycentric form urban than monocentric form urban. However, findings from these studies do not imply that increasing air pollution in region or country is accompanied by the expanding megacities. Using satellite night-light data, this study investigates the impact of polycentric urban form at the provincial level on PM2.5 concentrations in China while controlling for variables of urban population size, energy consumption, and the weather. The results reveal that the PM2.5 concentrations are reduced by 1.46% to 2.67%, with a 1% increase in polycentric urban form. The similar impact has also been observed in the South China, but larger in the Central China. Further studies show that the urban form-air pollution relationship mainly influenced by transportation distance and enhanced by rising per capita income. The findings suggest that regional planning and policies favoring polycentric urban patterns should be strengthened to alleviate air pollution.