Though the environmental Kuznets curve (EKC) was originally developed to model the ambient concentrations of pollutants, most subsequent applications have focused on pollution emissions. Yet, it seems more likely that economic growth could eventually reduce the concentrations of local pollutants than emissions. We examine the role of income, convergence, and time-related factors in explaining recent changes in PM 2.5 and PM 10 particulate pollution in 50 Chinese cities using new measures of ambient air quality that the Chinese government has published only since the beginning of 2013. We use a recently developed model that relates the rate of change of pollution to the growth of the economy and other factors as well as the traditional environmental Kuznets curve model. Pollution fell sharply from 2013 to 2014. We show that economic growth, convergence, and time effects all served to lower the level of pollution. The results also demonstrate the relationship between the two modeling approaches.