The three main anthropogenic sources of gaseous air pollutants in the united states are

The pollution present in the air is primarily categorized as chemical, physical and biological sources, apart from this it is also categorized as natural and anthropogenic sources of pollution. The anthropogenic sources of pollution are caused mainly due to human activities, that is, these are the man-made sources of pollution.

The anthropogenic pollution arises due to deforestation, burning of fossil fuels, discharges originating from the industries, fertilizers, and pesticides, etc. The prime anthropogenic pollutants present in the air originate due to the combustion of fossil fuels. In the United States, the three prime anthropogenic sources of gaseous air pollutants are transportation, industry, and production of energy.