This paper is on the topic of air pollutants. Air pollution pertains to substances and gases in the air that threaten health and life. Among these are pollutants and irritants, such as nitrogen oxides, sulfur dioxide, and carbon dioxide; particulates, volatile organic compounds (VOCs), toxic substances and some natural substances, like pollen. But most of the pollution comes from the by-products of industrialization - fossil fuel combustion, transportation, transportation, power plant emissions and those from other industrial processes. The burning of fossil fuels to generate electricity alone is the greatest source of air pollution in the USA. These outdoor pollutants can undermine health and cause environmental disturbances, such as acid rain, and are toxic.