Arsenic Exposure And its Effect on Health

Arsenic is known as a poison and human carcinogen. Arsenic trioxide (As2O3), a water-soluble powder that produces a colorless, tasteless, and odorless solution, was a favorite homicidal agent during the Middle Ages and its use continues today, although not to the same extent. There is much debate on Napoleon's death, whether he was poisoned by arsenic-tainted wine during his exile on the island of St. Helena.



Arsenic is the 20'th most abundant element in the earth's crust, and is present in the natural environment. The current problem of arsenic is devastating in history as the cause of the largest mass poisoning ever. In Bangladesh and India, millions of people are affected by high levels of arsenic in drinking water. Millions of wells have been installed since the 1970''s with the aim of providing clean water, free of microbial pathogens. However, the rock containing naturally high levels of arsenic releases of arsenic in water, arsenic in water higher than concentration several hundred micrograms per liter (µg/L) or even milligrams per liter (mg/L) in some wells. Ingestion of such high levels of arsenic in drinking water over several years can lead to a variety of adverse health effects including cancers of the skin, bladder, and lung as well as possible neurological and cardiovascular effects.



The magnitude of the arsenic problem and the seriousness of the adverse health outcomes resulting from exposure to arsenic make arsenic the single most important environmental contaminant. As a consequence, regulations on arsenic have become more stringent. Arsenic is also abundant in seafood at concentrations as high as several hundred micrograms per gram (µg/g). Arsenobetaine is the major arsenic species in most seafood (crustaceans). It is excreted into urine without metabolism, and is essentially non-toxic.

Arsenic-induced hyperkeratosis of the hands

More than 20 arsenic compounds (species) are present in the natural environment and biological systems. The following Table lists some of the common arsenic species. Although the trivalent arsenic species, such as inorganic arsenite (AsIII), monomethylarsonous acid (MMAIII), and dimethylarsinous acid (DMAIII) are highly toxic (8-13), arsenobetaine (AsB), the predominant arsenic species present in most crustaceans, is essentially non-toxic.