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Overview of air pollution
Published in Abhishek Tiwary, Ian Williams, Air Pollution, 2018
Air pollutants may be classified in many ways but typically take either gaseous or particulate forms (respectively covered in Chapters 2 and 3). Unwanted chemicals or other materials can enter the atmosphere either from natural sources, such as volcanoes, dust storms and forest fires, or be from human-made, known as anthropogenic, sources. The anthropogenic sources can be subdivided into stationary or point sources and area or mobile (linear) sources (respectively covered in Chapters 4 and 5). Point sources include stacks, flues and chimneys. Area sources include groupings of usually small sources spread over an area, such as an industrial complex like a steel works or the combined emissions from domestic heating in a town, landfills, and so on. Mobile sources include cars, aeroplanes, ships and trains. Line sources are pollution that emanate from a linear direction; the most obvious linear sources are from roads and aircraft.
Contaminated Sites
Published in Paul Lecomte, Polluted Sites, 2017
In both cases the form of the source of pollution constitutes an element of fundamental classification: — The source of pollution is an ‘area-source’ when spread over a large area or the contaminant introduced into the surroundings is distributed over a large space. A typical example is related to the fallout of smoke (with a concentration of contamination which decreases as one moves away from the point of emission).— The source of pollution is a ‘point-source’ when the contaminant is introduced at an exact point and restrained in space. This is the case, for example, of a leakage at the level of a storage tank.— The source is a ‘line-source’, horizontal (waterways, network of underground or surface channels) or vertical (empty well, drill hole, mine shaft) when the contaminant is distributed along the route while transporting the pollutant from one place to another by a device with a chronic defect in watertightness or even accidental rupture at many points.
Air Pollutants and Their Adverse Effects
Published in Jeff Kuo, Air Pollution Control Engineering for Environmental Engineers, 2018
Stationary sources can be further divided into two main subcategories: point and area sources. Point sources consist of a single emission source with an identified location point at a facility. Facilities could have multiple point sources located onsite. Point sources are usually associated with manufacturing and industrial processes, such as boilers, spray booths or degreasers. Area sources are small emission sources that are widely distributed, but may have substantial cumulative emissions; examples include residential water heaters, small engines, and consumer products, such as barbecue lighter fluid and hair spray.
Residential wood heating: An overview of U.S. impacts and regulations
Published in Journal of the Air & Waste Management Association, 2022
Arthur Marin, Lisa Rector, Barbara Morin, George Allen
Wood heating emissions also contain a number of carcinogenic compounds, including POM, benzene, and aldehydes. US EPA estimates that this source is responsible for 25% of cancer risk and 15% of all non-cancer respiratory effects attributed to area source air toxics emissions (US EPA 2018). Given that rates of wood heating appear to be underestimated by the sources used to develop these risk assessments, the actual impact may be more significant.