Minor Sources of Air Pollution

Legal Differences

• Strong regulations are in place at state and local levels that regulate businesses that produce air pollution. However, regions differentiate between major and minor pollution sources. The difference has a large effect on what permits are required and what regulations need to be followed. For instance, in Wisconsin, a facility that puts out less than 250 tons annually of air pollution is a minor source of air pollution. That number needs to be less than 100 tons if the facility falls into certain business categories such as kraft pulp mills or glass fiber processing plants.

Area Sources

• Area sources of air pollution are made up of multiple tiny sources that combine to create a measurable effect on air pollution. By themselves, each of these sources would be so minor as to be almost invisible, but when combined with many other similar minor pollutants, it becomes an area source. The Environmental Protection Agency uses the example of a town full of homes burning wood in wood stoves to illustrate the definition of area sources.

Natural Sources

• The air pollution created through natural Earth processes is not minor in terms of the volume of pollutants these systems produce. However, it is considered minor because those processes went on for thousands of years without causing damage to the Earth's environment because the atmosphere was in a state of natural equilibrium. It is the added human pollution that poses a threat. Natural sources of air pollution include volcanoes, swamps and forest fires caused by lightning strikes.

Incidental Activity

• Many businesses conduct activities daily that produce small amounts of air pollution. These sources are generally considered insignificant when they come from a single business, but as an industry, even these activities produce measurable pollution. Examples of this include painting, such as when contractors use spray painting equipment to paint large buildings. Mechanic shops are another minor source of pollution. Many activities, such as welding, brake work and routine cleaning in a shop, produce some amount of air pollutants.