Heavy metal poisoning

A number of metals have been known for several decades to possess biological activity. Since mammals must directly or indirectly obtain their supply of minerals from plants, it has been postulated that any element not present in plants is probably not important to the human body (1). Conversely any metal found in the human body but not in plants is probably present as an environmental contaminant and should possess no metabolic function. Elements are usually classified as essential or nonessential, then further divided into micro- and trace-elements. Some metallic elements, especially heavy metals, or their compounds introduced into living organisms in sufficient amounts, may have injurious or deadly effects, chemically producing a toxic condition. These poisons could get into the system through the mouth by swallowing or breathing, into the bloodstream (intravenously), under the skin (subcutaneously) or by absorption through the skin. The general symptoms of heavy metal poisoning are abdominal pain, vomiting, purging, metallic taste, and bloody diarrhea (2).