Mercury Poisoning

Mercury poisoning definition and facts*

*Mercury poisoning facts by John P. Cunha, DO, FACOEP

  • Mercury is a naturally occurring element found in air, water and soil. A highly toxic form (methylmercury) builds up in fish, shellfish and animals that eat fish. Fish and shellfish are the main sources of methylmercury exposure to humans.
    • Fish that typically have higher levels of mercury include king mackerel, marlin, orange roughy, shark, swordfish, tilefish, and ahi and bigeye tuna. Many of these types of fish are used in sushi.
  • Other sources of mercury can be silver-colored dental fillings that contain up to 50% mercury by weight and can release mercury vapor, fluorescent light bulbs that use electricity to excite mercury vapor, and mercury fever thermometers made of glass.
  • Mercury exists in several forms: elemental or metallic mercury, inorganic mercury compounds, and organic mercury compounds.
  • Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system. High levels of methylmercury in the bloodstream of unborn babies and young children may harm the developing nervous system, making the child less able to think and learn.
  • Signs and symptoms of methylmercury poisoning may include:
    • Impairment of peripheral vision
    • Disturbances in sensations ("pins and needles" feelings)
    • Lack of coordination
    • Impairment of speech, hearing, walking
    • Muscle weakness
  • Elemental (metallic) mercury primarily causes health effects when it is breathed as a vapor where it can be absorbed through the lungs.
  • Signs and symptoms of acute elemental (metallic) mercury poisoning include:
    • Tremors
    • Emotional changes
    • Insomnia
    • Weakness
    • Muscle atrophy
    • Twitching
    • Headaches
    • Disturbances in sensations
    • Changes in nerve responses
    • Performance deficits on tests of cognitive function.
  • Higher exposures may result in kidney effects, respiratory failure and death.
  • Consult your doctor if you believe you have been exposed to mercury. Testing for mercury may involve tests on the hair, blood, and urine. Treatment for mercury toxicity includes removal of the source of mercury exposure, supportive care, and chelation therapy to help remove the metals from the body.
  • Recycling of mercury-containing products is one of the best ways to help prevent mercury releases to the environment by keeping these products out of landfills and incinerators.

What is mercury?

Mercury is a naturally occurring element. It is contained in some of the fish we eat, whether caught in local lakes and streams or bought in a grocery store. Mercury is also contained in some of the products we use, which may be found in your home, at the dentist, and at schools. This article provides links to information about sources of mercury exposure, potential health effects, fish that may contain mercury, consumer products that contain mercury, and ways to reduce your exposure to mercury.

Medically Reviewed by a Doctor on 9/12/2016

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