Who will talk about the air contrast between Beijing, Xiamen and Shanghai?

I only know that Beijing, Shanghai and Xiamen have never lived and studied, so I can't talk about it. I majored in environment, and studied the air quality in Beijing and Shanghai when I was in college.

The data given by the academic community is probably like this. If we compare the nitrogen oxides, sulfides and carbon oxides in the air, the air in Shanghai is much worse than that in Beijing. If you compare particulate matter, Beijing is slightly worse than Shanghai. The reason is that there are many chemical plants, Baosteel, Jinshan Chemical Zone, plastic factories and so on near Shanghai, and there are many industrial emissions. Beijing, as you know, the capital, all industrial manufacturing industries are not allowed to be built near the capital, and they have all moved to other provinces.

But there are many inhalable particles in Beijing. Because of the ups and downs in Inner Mongolia, straw burning in the northeast and coal burning in the northeast and north China for heating, Beijing is prone to foggy days in winter, which is caused by the high concentration of particulate matter.

So the air in Shanghai seems cleaner than that in Beijing, but it may not be as fresh as that in Beijing. Because most pollutants in Shanghai are chemical emissions, it is not very beautiful.