Arsenic is used as a preservative, pesticide, herbicide and as a semiconductor enhancement. The toxic element is found in inorganic and organic compounds and can cause grave problems if humans come into contact with it.
Arsenic is a chemical element. It occurs in many minerals, usually combined with sulfur and metals. It's also found as a pure elemental crystal.
The inorganic arsenic compound CCA is used to treat lumber. The compound works to prevent rot and insect damage. Most pressure-treated lumber is used to build homes, decks, fences and playground sets. Arsenic is used to preserve animal hides in taxidermy as well.
Arsenic is added to lead-acid batteries and copper compounds. Arsenic stabilizes the alloys to increase the longevity of the part. The ammunition industry uses arsenic to create hard, rounder bullets.
According to WebMD, arsenic is effective for treating acute promyelocytic leukemia, a rare form of leukemia. It's administered through a prescription-only IV drip. Before the development of penicillin, arsenic was used to treat syphilis, as well as many other medical issues until modern medicine found safer methods to treat specific illnesses.
Prior to 2009, chicken farmers added arsenic to poultry feed to facilitate rapid weight gain and decrease diseases in chickens.