The correct answer is this one: "human industrialization." Air pollution comes from human industrialization. Because of too much industrialization, there are a lot of excess and wastes in any form: air or even liquid and solid wastes.
Air pollution has come from a variety of sources,but the main one is the human industralization, from the usage of cars and vehicles that are fueled by oil-derivates to the residuals of CO2 by most of the fabrics and industries that we use to create products.
