As a prominent indicator of economic development, urbanization can exert a significant impact on the PM_2.5 level. Using panel data from 126 countries (areas) over the period 1990–2016, this study investigates the relationship between urbanization level and PM_2.5 density. A modified stochastic impacts by regression on population, affluence, and technology model is applied as the empirical strategy. Results show that the relationship between urbanization and PM_2.5 density has an inverted U shape. The effects of urban agglomeration and technological progress reduce the density of PM_2.5 in the late stage of urbanization. This study can help policymakers design appropriate measures relevant to PM_2.5 attenuation in the context of breakneck urbanization.

作为经济发展的重要指标，城市化可以对PM _2.5产生重大影响。使用1990年至2016年期间来自126个国家（地区）的面板数据，本研究调查了城市化水平与PM _2.5密度之间的关系。通过回归对人口，富裕程度和技术模型进行修正的随机影响作为经验策略。结果表明，城市化与PM _2.5浓度之间的关系呈倒U型。城市集聚和技术进步的影响降低了城市化后期PM _2.5的密度。这项研究可以帮助决策者设计与PM _2.5相关的适当措施 在极速城市化的背景下衰减。