Spatial-temporal characteristics and determinants of PM2.5 in the Bohai Rim Urban Agglomeration

The BRUA, one of the major PM2.5 polluted regions, had an annual average of 74 μg/m3, much higher than the national level (61 μg/m3). PM2.5 pollution in this region presented a decreasing trend from the inland (southwest) towards the coastal area (northeast), namely, Beijing-Tianjin-Hebei and western Shandong were seriously polluted, with central-western Hebei as the core area.