ABSTRACT
Arsenic (As) is widely distributed in the earth’s crust with an average concentration of 2 mg/kg. Mining, smelting of non-ferrous metals and burning of fossil fuels are the major sources for anthropogenic arsenic pollution (IPCS 2001). Arsenic is a metalloid with 4 oxidation states; arsenite As (III) is the dominant form under reducing condition and arsenate As (V) is the stable oxidised form in the environment. The most common mineral species of arsenic is arsenopyrite. Arsenites are more soluble and mobile than arsenates and the more toxic form (ATSDR 2007). Salts of arsenic, particularly sodium arsenite and sodium arsenate, are the most water soluble forms. About 90% of produced arsenic in recent years was used as wood preservative in Copper Chrome Arsenate (CCA) and for inorganic arsenic pesticides in cotton and horticulture. The concentration of arsenic in the terrestrial environment may increase significantly as a result of mining activities (El Khalil et al. 2008).
