A national analysis of the geographic aspects and ecological correlates of PM2.5 in China based on ground observational data

Abstract

Increasing studies have investigated the characteristics of fine particulate matter of less than 2.5 μm (PM2.5) using ground-level observations among Chinese cities in recent years. This article analyzed the geographic aspects and ecological correlates of PM2.5 based on in situ ambient air quality observations for 367 cities and prefectures across China. Results of global and local Moran’s I analyses suggested a significant clustered pattern of PM2.5 across the country with hot spots mainly concentrated in cities located in the North China Plain. Spatially interpolated PM2.5 estimates showed that most of China’s territories experienced unhealthy concentrations of PM2.5 except during summer, while much larger proportions of China’s population was exposed to unhealthy PM2.5 all year round. Results from regression analyses suggested that the spatial variations of PM2.5 were positively associated with air pollution but inversely related to meteorological factors. Findings from this research can provide new insights into air pollution mitigation policies and public health efforts in China and beyond.