Pages: 8 (1775 mots) Publié le: 3 octobre 2010
Arsenic: A Deadlier Neighbor between Us


Kadiatou Diallo

Professor Letitia Mongomery

September, 2010

Arsenic: A Deadly Neighbor between UsNature includes an enormous number of elements in different states of matter. The variety of the elements allows living organisms to keep alive; however, in certain combinations, some elements show the risk of becoming poison. That is the case of Arsenic (As, is its symbol), present in the earth’s crust as the 20th most abundant element and in the human body as the 12th most abundant element(Schroeder & Balassa, 1966). Considering its massive presence in nature, Arsenic can be found in different materials and living organisms. This does not have any risk of harm, except when in certain amounts. Because of this situation arsenic can be useful but also dangerous. This element has caused numerous cases of poisoning through the history of poisonous elements, because for a long time humanswere not aware about how dangerous it could be. Arsenic is known best as a deadly poison, although in small doses it does have medical benefits. Arsenic poisoning can be reviewed related to the origin of this poison, its presence in different compounds, and some famous cases around the world.

Origin of Arsenic

Arsenic is a commontoxic element in the environment (Goyer & Mehlman, 1977), which has a bad reputation (Emsley, 2005) among the rest of the elements due to the deadly effects that it can produce. The presence of arsenic was identified first by Albertus Magnus (1193-1280), and even though it was recognized as an element a long time after that (Emsley, 2005), there is evidence of its existence since the ancient Romans(40-90 AD). The name arsenic comes from the Greek voice arsenikum which means yellow orpimente, which refers to the color of the element in some materials containing it. In its natural state when extracted from mines, arsenic is an obscure and gray element which is classified as a heavy metal poison (Blum, 2010). This element is naturally combined with other elements like oxygen, chlorine andsulfur, being named inorganic arsenic. If arsenic is combined with carbon and hydrogen is called organic arsenic. The majority of arsenic combinations, both inorganic and organic compounds, are white or colorless, odorless and tasteless powders that do not evaporate. Results are imperceptible if it contaminates food, water or air (ATSDR, 2010). When heated with oxygen, it is transformed into a whitegrainy powder, named arsenic trioxide (As2O3) (Blum, 2010). Arsenic trioxide, or white arsenic, has been used by terrible poisoners of history, even though its presence in nature as a non-combined element is very common.

Presence of Arsenic in Nature

Arsenic can be found in different states of matter, as a liquid, solid or gas. Therefore, it is possible to find this toxic element in potablewater, mineral water and seawater in different concentrations. Also it is found in soil and rocks, especially in arsenopyrites, realagar, orpimente and arsenolite; however, the element is not commonly mined, but extracted as a by-product from the process of melting copper, lead and other ores. (Goyer & Mehlman, 1977) In the air, arsenic can be present as micro particles or dust that comes fromthe melting process of mineral rocks, as a result of the heat process used to extract the minerals (ATSDR, 2010). Moreover, natural presence of arsenic in minerals has become a problematic situation due to industrial processes associated with the extraction of minerals such as copper. These processes can liberate the element into the environment, affecting humans, fauna and flora surrounding these...
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