Influence of socioeconomic factors on PM 2.5 pattern in China’s megacities between 2013 and 2019

Abstract

In the last decade, Chinese megacities have undergone rapid and massive urbanisation that resulted in rising PM2.5 levels in megacities, which forced the government to implement stricter air quality guidelines to combat it. This study investigates the effectiveness of the five-year (2013–2017) air combat plan in reducing PM2.5 in these megacities since they have achieved a certain level of urbanisation. The findings show that annual concentrations of PM2.5 exceeded the World Health Organization (WHO) guideline value, and eight out of ten cities exceeded the national ambient air quality standard (NAAQS) guideline value. Although, on an annual level, a consistent downward trend was observed for PM2.5 values among all cities starting from 2013, indicating positive policy feedback from guidelines. The cumulative rate of change in PM2.5 concentrations from 2013 to 2019 indicated that the highest magnitude of the decrease occurred in Beijing and Chengdu (-59%). The Environmental Kuznets curve was observed for PM2.5 with GDP and Industrial SO2 emission. A negative relationship was observed between PM2.5 and secondary industry share, while the contrary was observed between PM2.5 and Industrial NO2 emissions. Our data indicated that stricter sanctions and emission policies are needed to lower the PM2.5 values in most of these megacities.