Metal poisoning or metal toxicity are the harmful effects caused by specific metals in specific forms. It is a common misconception that all toxic metals are heavy metals, but even lighter metals such as beryllium are listed as Category 1 carcinogens by the International Agency for Research on Cancer. And not all heavy metals are toxic, for example nickel which promotes cell growth. The reason for the toxic effects of these metals is due to the ability to mimic other metals and cause malfunctions in the human body. Example Beryllium has the same properties as magnesium and displaces it from enzymes and becomes defective. They therefore interfere with the metabolic process and cause damage. The most common toxic metals are: Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Metals that have no confirmed biological role such as lead, cadmium, mercury etc. Metalloids such as arsenic, antimony. Radioactive metals that cause radiation damage and chemical toxicity. Abnormal forms of essential metals such as chromium (+3) play a role in the action of insulin, while chromium (+6) is carcinogenic. The level of toxicity of the metal depends on the ligand to which it is attached; example: methyl mercury is more toxic than elemental mercury or its salts. The toxicity of a metal also depends on its solubility and absorbability. Bismuth is relatively less toxic than other heavy metals because its salts are less soluble, making them common in numerous medicines. The main types of metal poisoning:Arsenic poisoning: is poisoning caused by higher levels of arsenic in the body. The causes are drinking water (10-50 ppb is considered safe), arsenate pesticides (although banned, residues still remain), copper smelting which produces arsenic as a by-product. Beryllium Poisoning: It is the toxic effect caused by beryllium and its compounds. It is a carcinogen.Cadmium Poisoning: Caused by Smoking, Industries that produce Cadmium-Nickel batteries. The maximum prescribed concentration of cadmium in drinking water is 0.005 ppm.Argyria: It is a disease caused by high exposure to silver; it can be caused by direct intake or deposition of silver or silver sulfide on the skin. This image shows the change in skin color due to argyria in an elderly man who had used nasal drops contaminated with silver. The silver had deposited in the dermis, changing the color. Zinc Toxicity: Zinc becomes toxic by ingesting more than 225 mg of zinc, can occur during electroplating. The maximum prescribed concentration of Zn in drinking water is 5.0 ppm. Lead poisoning: occurs when the concentration of lead in the blood is greater than 10 μg/dl. The reason for lead pollution is due to human activities such as lead battery recovery plants, use of tetraethyl lead as anti-knock agents, paints, bullets. The main sources of absorption of inorganic lead are from ingestion and inhalation. Mercury poisoning: caused by eating seafood such as fish (larger fish such as whales, tuna) that contain a high concentration of methyl mercury (formed from inorganic mercury by the action of microbes in lakes, rivers, open ocean ), Inhalation of mercury vapor. Mercury salts affect the gastrointestinal tract and also cause serious damage to the kidneys. Metal poisoning in our history and some terrible cases: Arsenic: The Greek geographer and historian wrote that only slaves worked in the royal mines and in space, because they would surely die from the poison..