Source 22

1. http://www.eoearth.org/article/Air_pollution_in_China
2. The source is The encyclopedia of Earth by Sjaak Slanina.
3. The credentials include Sjaak Slanina who is just the lead author and reporter on this air pollution topic.
4. My source says that recent journal articles have been produced that show China is not the number one polluter in the world. It also gives several data tables showing the top 10 and top 20 leading pollution cities in the world.
5. I somewhat believe the source.
6. I don't completely believe the source because it says that China is not the leading producer of pollution in the world which is hard to believe because of how big China is. However I think they meant in terms of pollution in terms of size of city or country compared to amount of pollution putting out. This would then make a lot more sense that China is not number one but it is still up there.