Air pollution

Sources of air pollution refer to the various locations, activities or factors which are responsible for the releasing of pollutants in the atmosphere. These sources can be classified into two major categories which are:
1. Anthropogenic sources(human activities) mostly related to burning different kinds of fuel. Examples of such sources are chemicals, dust and controlled burn practices in agriculture and forest management controlled or prescribed burning is a technique sometimes used in forest management, farming, prairie restoration or greenhouse gas abatement.
2. Natural sources. Examples of natural sources are dust from natural sources, usually large areas of land with little or no vegetation.
Methane, emitted by the digestion of food by animals, for example cattle.
Radon gas from radioactive decay within the Earth's crust.Radon is a colorless, odorless, naturally occurring, radioactive noble gas that is formed from the decay of radium. It is considered to be a health hazard.Radon gas from natural sources can accumulate in buildings, especially in confined areas such as the basement and it is the second most frequent cause of lung cancer, after cigarette smoking.
Smoke and carbon monoxide from wildfires.
Volcanic activity, which produce sulfur, chlorine, and ash particulates.

These are the two main sources that cause air pollution.