What is arsenic?
Arsenic (As) is a naturally occurring semi-metal. Arsenic can combine with other elements to form inorganic and organic arsenicals. Most inorganic and organic arsenic compounds are white or colorless powders that do not evaporate. They have no smell, and most have no special taste. Thus, you usually cannot tell if arsenic is present in your food, water, or air.
Presently about 90% of all arsenic produced is used as a preservative for wood to make it resistant to rotting and decay. The preservative is chromated copper arsenate (CCA) and the treated wood is referred to as "pressure-treated." Organic arsenic compounds are used as pesticides, primarily on cotton plants. In general, inorganic derivatives are regarded as more toxic than the organic forms. While food contains both inorganic and organic arsenicals, primarily inorganic forms are present in water.
Exposure to arsenic at high levels poses serious health effects as it is a known human carcinogen. In addition, it has been reported to affect the vascular system in humans and has been associated with the development of diabetes.
How does Arsenic enter the environment?
Inorganic arsenic occurs naturally in soil and in many kinds of rock, especially in minerals and ores that contain copper or lead. When these ores are heated in smelters, most of the arsenic goes up the stack and enters the air as a fine dust. Smelters may collect this dust and take out the arsenic as arsenic trioxide. However, arsenic is no longer produced in the United States; all the arsenic we use is imported.
Arsenic cannot be destroyed in the environment. It can only change its form, or become attached or separated, from particles. Arsenic in air will settle to the ground or is washed out of the air by rain. Many arsenic compounds can dissolve in water. Fish and shellfish can accumulate arsenic, but the arsenic in fish is mostly in a form that is not harmful.
Arsenic translocated to soil and water via: leaching from wood, runoff from lumber yards, sawdust and physical wearing of the wood.
How do people get exposed to arsenic?
Consumption of food and water are the major sources of arsenic exposure for the majority of US citizens. People may also be exposed from industrial sources, as arsenic is used in semiconductor manufacturing, petroleum refining, wood preservatives, animal feed additives, and herbicides.
Fish and seafood contain the greatest amounts of arsenic, but this is mostly the organic form of arsenic that is less harmful.
What are the symptoms of arsenic poisoning?
The typical symptoms are; diaphoresis, muscle spasms, nausea, vomiting, abdominal pain, garlic odor to the breath, diarrhea, anuria, dehydration, hypotension, cardiovascular collapse, aplastic anemia and death. The degree to which symptoms a person has will be determined by the severity of the exposure.
Water: The current maximum contaminant level (MCL) for arsenic of 50 ppb was established by EPA in 1975. The standard was based on a 1942 Public Health Service standard. On October 31, 2001 EPA announced its decision to move forward in implementing the arsenic standard for drinking water at 10 ppb. See the Latest News.
Consumer Safety Information Sheet on Inorganic Arsenical Pressure-Treated Wood http://www.epa.gov/oppad001/reregistration/cca/cca_consumer_safety.htm
Arsenic in Ground-Water Resources of the United States http://co.water.usgs.gov/trace/pubs/fs-063-00/
Center for Disease Control (CDC)’s Agency for Toxic Substances and Disease Registry (ATSDR) Profile Information Sheet http://www.atsdr.cdc.gov/tfacts2.html