Point source pollution

http://en.wikipedia.org/wiki/Point_source_pollution

From Wikipedia, the free encyclopedia 

point source of pollution is a single identifiable source of airwaterthermalnoiseor light pollution. A point source has negligible extent, distinguishing it from other pollution source geometries. The sources are called point sources because in mathematical modeling, they can be approximated as a mathematical point to simplify analysis. Pollution point sources are identical to other physicsengineeringoptics, andchemistry point sources and include: