Chemical pollution is emitted on a daily basis by thermal power plants, cars, mines, refineries, and other similar manufacturing facilities. Cement and metal processing such as that used to create steel also add chemical pollutants to the atmosphere, as does the manufacture of pesticides, herbicides, and other chemicals.

Many nations have enacted pollution control laws designed to reduce factory emissions through the use of filters and modernized facilities.

http://www.ndri.com/news/toxic_exposures_due_to_chemical_pollution_have_severe_long_term_effect-301.html

http://www.commondreams.org/headlines06/1108-08.htm

http://www.peopleandplanet.net/doc.php?id=2967

Hope that helps! Best wishes!