Mercury (Hg) is a naturally occurring element found in many minerals such as gold, silver, copper and lead. When ingested or inhaled it enters the blood stream where it binds with proteins causing them to change shape. These changes cause the release of toxic chemicals into the bloodstream which are then excreted through urine and feces. The most common form of mercury poisoning is acute toxicity caused by ingestion of methylmercury (MeHg). Chronic exposure to mercury causes damage to the central nervous system and other organs.
The most well known form of mercury poisoning is due to inhalation of methylmercury (MeHg). MeHg is formed when coal burning power plants produce highly contaminated water containing high levels of heavy metals like mercury, cadmium, arsenic and others. The amount of mercury released into the air increases rapidly with increased coal burning power plant emissions.
When inhaled, MeHg accumulates in the lungs and eventually damages them leading to irreversible lung damage. There are no known effective treatments for MeHg poisoning. Even if one were to survive a few years, there would be permanent neurological damage and death.
There are two forms of mercury toxicity: acute and chronic. Acute mercury poisoning is rare and occurs mainly through the touching of concentrated liquid mercury or through eating fish containing high levels of organic mercury. However, one of the most common types of acute mercury poisoning is when dentists use a liquid form called “silver nitrate” to create silver fillings (amalgams). These fillings are approved by the Food and Drug Administration (FDA) but are known to release toxic levels of heavy metals like mercury and lead.
An even more serious case of acute mercury poisoning is when a person ingests elemental mercury. When a dentist spills elemental mercury it creates a vapor when it touches the moisture inside the mouth. Once ingested, the body cannot differentiate between elemental and organic forms of mercury.
Most cases of chronic mercury poisoning are caused by eating fish high in methylmercury (MeHg). MeHg binds to the proteins in fish and remains there as it is passed up the aquatic food chain. Large fish like shark and swordfish eat smaller contaminated fish for food, which concentrates the heavy metals in their bodies. Although the levels of mercury and other toxic metals are low in these fish, people often eat them on a regular basis thinking that they are a good source of protein.
One of the most common causes of chronic mercury poisoning is from eating canned tuna.
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