Which air quality is better, Nanjing or Jinan?

There is a lot of smog in Jinan, and there are sandstorms from Beijing in spring. This problem does not exist in Nanjing. In contrast, the air quality in Nanjing is good.

The air quality reflects the degree of air pollution, which is judged according to the concentration of pollutants in the air. Air pollution is a complex phenomenon. At a specific time and place, the concentration of air pollutants is affected by many factors.