The article discusses how air pollution control models were used in the Beijing-Tianjin-Hebei urban area. They looked at different ways to reduce pollution, like changing industry practices and transportation. The study found that pollution levels decreased for most pollutants from 2014 to 2017, except for O3. O3 levels were highest in summer and lowest in winter, while other pollutants were highest in winter and lowest in summer. O3 pollution spread from south to north, while other pollutants decreased from north to south. The researchers suggest improving pollution tracking, joint legislation, and supervision to help control air pollution in urban areas.