Changes in Long-Term PM2.5 Pollution in the Urban and Suburban Areas of China’s Three Largest Urban Agglomerations from 2000 to 2020

Particulate matter (PM2.5) is a significant public health concern in China, and the Chinese government has implemented series of laws, policies, regulations, standards to improve air quality. This study documents changes PM2.5 evaluates effects industrial transformation clean policies on levels urban suburban areas China’s three largest agglomerations, Beijing–Tianjin–Hebei (BTH), Yangtze River Delta (YRD), Pearl (PRD) based new degree urbanization classification method. We used high-resolution concentration population datasets quantify differences concentrations these agglomerations. From 2000 2020, have expanded while shrunk. were approximately 32, 10, 7 μg/m3 higher than those from 2020 BTH, YRD, PRD, respectively. Since 2013, regions PRD declined at average annual rates 7.30, 5.50, 5.03 μg/m3/year, respectively, 3.11, 4.23 4.69 By 2018, all satisfied their specific targets Air Pollution Control Action Plan. declines exceeded by two, three, four times, However, exposure risks are 10–20 times areas. China will need implement more robust pollution mitigation achieve World Health Organization’s Quality Guideline (WHO-AQG) reduce long-term risks.