Long-Term Effects of Mercury Poisoning

Mercury is a heavy metal that occurs naturally in small amounts. It is a known neurotoxin with systemic effects, ranging from kidney damage to mental retardation and death, and may play a role in some developmental disorders. Long-term effects of mercury poisoning depend on a number of factors, including the form and amount of mercury to which you are exposed, age at the time of exposure and physiological ability to excrete the metal.

Elemental Mercury

• Elemental mercury is mercury in its metallic liquid form. The greatest danger from elemental mercury is its ability to release toxic vapors. Mercury in this form is most harmful to the central nervous and pulmonary systems. Long-term effects of chronic or high-dose elemental mercury exposure include tremors, depression and mental health problems, nervousness and failure to develop myelin sheaths in the brains of children exposed early in development.

Organic Mercury

• Organic mercury compounds are generally considered to be more harmful than the element in its natural state. Major sources of exposure include methylmercury in seafood and ethylmercury in vaccines and other products containing the preservative Thimerosal. Organic mercury compounds are capable of causing significant brain and liver damage. Dimethylmercury--the most toxic of these compounds--can cause death through skin absorption of only a few microliters. The long-term effects of organic mercury include tingling and numbness in the extremities, loss of hearing, blindness and mental retardation in babies exposed in the womb.

Inorganic Mercury

• The inorganic mercury group is composed of mercury salts like mercuric chloride. Its major effects are on the kidneys, though reproductive and endocrine disorders may also result. When ingested orally, inorganic mercury causes severe gastrointestinal distress in the form of vomiting and severe pain. Long-term effects may include development of kidney and thyroid tumors, disturbances in peripheral vision, tremor and personality changes.

Additional Contributing Factors

• In addition to the form of mercury to which you are exposed, other factors play a role in determining the long-term effects. Age of exposure is extremely important in determining the extent of the damage from mercury. Those exposed during critical developmental periods in the womb and in early childhood are at risk for more severe problems than adults exposed to similar amounts of the same substance. According to experts at the Environmental Protection Agency (EPA), children exposed to high concentrations of methlymercury in the womb experienced significant central nervous system damage, including cerebral palsy, blindness, deafness and developmental delays.

  The amount of mercury to which one is exposed and the duration of exposure may also influence the final outcome. Chronic low level exposure may result in different effects than a one-time acute exposure due to the body's ability to excrete the metal.

Warning

• If exposed to mercury in any of its forms, seek medical help. Tests for mercury toxicity can determine whether you have been exposed and to what extent. A doctor will determine the most appropriate treatment for your particular situation.