Acid rain

Description

Acid rain is defined as precipitation (rain, snow, or sleet) having a pH below 5.6 . Nonpolluted rain has a pH of about 5.6 due to the dissolved carbon dioxide that naturally forms some carbonic acid. More deleterious pollutants, such as sulfur dioxide and nitrogen oxides, are produced from combustion sources, coal smoke, chemical manufacturing, and smelting. Water vapor condenses on the pollutant particles and reacts to form acids. This acidic precipitation is very detrimental as it can kill trees, destroy freshwater animals, corrode metal, and dissolve carbonaceous stones (limestone and marble).

Synonyms and Related Terms

acid precipitation; acid deposition; Saurer Regen (Deut.); pluie acide (Fr.); zure regen (Ned.); lluvia ácida (Esp.); chuva ácida (Port.);

Authority

• Encyclopedia Britannica, http://www.britannica.com Comment: "acid rain." Encyclopædia Britannica. 2005. Encyclopædia Britannica Premium Service 1 June 2005 . - gives pH level as 5.6 or below

• Website address 1 Comment: http://amol.org.au/recollections/7/a/htm - gives pH as below 5.7

• Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Acid_rain - defines as pH below 4.0-4.5; source for language synonyms

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000