The term Area Source is used to describe a source of air pollution that affects a relatively small area, but cannot be classified as a point source. Some examples include vehicles, household or small business emissions, or biogenic sources such as forests which release hydrocarbons.
Source: U.S. Environmental Protection Agency. 2013. Terminology Service Terms of Environment. Accessed on 9 September 2013. Available at http://iaspub.epa.gov