What is arsenic?
Arsenic is a naturally occurring element found in soil, but also comes from industrial and agricultural sources. It is a powerful toxin that is frequently found in groundwater supplies. Prolonged exposure to very low levels of arsenic is linked to numerous cancers and other serious health problems. In February 2002, the EPA lowered the MCL for arsenic from 50 parts per billion, or ppb, to 10 ppb and mandated that all drinking water sold by water providers in the United States must meet the new standard, which we refer to as the Arsenic Rule, that went into effect January 23, 2006. According to the California Department of Water Resources, the Arsenic Rule also is expected to place over 500 groundwater sources out of compliance in California alone. Compliance with the Arsenic Rule is expected to result in increased regulatory costs over the next 20 years, with the EPA estimating that 5% of the 54,000 active community water systems in the United States, serving approximately 11.0 million
Arsenic is a naturally occurring element widely distributed in the earth’s crust. In the environment, arsenic is combined with oxygen, chlorine, and sulfur to form inorganic arsenic compounds. Arsenic in animals and plants combines with carbon and hydrogen to form organic arsenic compounds. Arsenic in soil occurs naturally, and is higher in some places than others due to geological conditions. Arsenic is found in higher than background concentrations in mine tailings or where there are airborne emissions from mining activities that deposit on the ground.
Arsenic is a naturally occurring element in the environment. It has no taste or smell. Although sometimes found in its pure form as a metal, arsenic is usually a part of chemical compounds. These compounds are usually divided into 2 general categories: • inorganic compounds (combined with oxygen, iron, chlorine, and sulfur) • organic compounds (combined with carbon and other atoms) Arsenic-contaminated inorganic compounds are found in industry, in building products (arsenic-treated wood), and in arsenic-contaminated water. This is the form of arsenic that tends to be more toxic and has been linked to cancer. Organic arsenic compounds in fish and shellfish may account for significant dietary intake of arsenic. These compounds are much less toxic than the inorganic arsenic compounds. Organic forms of arsenic have not been linked to cancer. Lead and copper ores are also commonly contaminated with small amounts of arsenic. How is Arsenic Used? Although arsenic is known to be a poison, arse
