Does urban sprawl exacerbate urban haze pollution?

Is rapid urban sprawl increasing environmental pollution while boosting economic development? This study uses panel data of 30 Chinese provinces during 2002-2018 to investigate the impact of urban sprawl on haze pollution with the use of a spatial lag model. Urban built-up area (ba) and urban public facilities occupation (upfo) are used to measure the differential impact of urban sprawl on haze pollution. The main highlights of the results are as follows: (1) there is a nonlinear relationship between urban sprawl and haze pollution. An inverted U-shaped relationship was found between built-up area and haze pollution, while urban public facility occupation and haze pollution have a U-shaped correlation. (2) The impact of urban sprawl on haze pollution shows a significant time-based difference. The relationship between the two was not significant in 2002-2010, but become significant in 2011-2018. (3) Significant regional differences in the impact of urban sprawl on haze pollution were found. The effects of urban sprawl on urban haze levels are more pronounced in the eastern and western regions than in the central region.