The study looked at air pollution in key cities along a pollution transmission route. They analyzed data from 2015 to 2019 and found that winter had the worst air pollution, while summer had the least. PM2.5 pollution mainly moved from high to low concentration areas, while PM10 pollution was influenced by local geography and climate. Industries like manufacturing and services were major sources of pollution. The study used math models to understand how pollution moves between regions and suggested better coordination between local governments to tackle the issue.