Arsenic. Whatever arsenic calls to mind, one thing is certain: It’s become synonymous with poison. Science supports that arsenic is “bad.” Classified as a human carcinogen by the EPA, it’s associated with lung, skin, bladder and liver cancers, among other health issues. Still, what’s compelling—and a mistake to ignore—is that a growing body of research shows that arsenic, at least at some dosage level, may be essential to life. How can a notorious poison possibly be good for us?
Arsenic is a common element that’s found almost everywhere. Some is naturally occurring and harmless; you‘ll find it in rocks and soil, water, air, and in plants and animals. Other arsenic compounds are man-made and toxic; they end up in the environment from industries such as mining and agriculture, where it’s used as a pesticide.
Classified as something between a metal and a nonmetal, arsenic is referred to as a metalloid or semi-metal. Other metalloids include boron and silicon, both of which play a significant role in human nutrition. Arsenic also falls into the category of “ultratrace element,” a term used to describe minerals that are found in the diet in extremely small quantities. It’s worth noting that two other infamous “heavy metals,” lead and cadmium are also considered ultratrace elements.
From a biological and toxicological perspective, there are three major groups of arsenic compounds:
· Inorganic arsenic compounds.
· Organic arsenic compounds.
· Arsine gas.
Organic “natural” arsenic, found in some foods, such as fish and shellfish, lacks toxicity while inorganic “man-made” arsenic, typically found in industry, building products, and in arsenic-contaminated water has been linked to cancer and chromosome mutations within cells. Arsine gas, which forms when arsenic comes into contact with an acid, is extremely toxic in humans.