Minamata Bay disease; Basra poison grain poisoning
Definition of Methylmercury poisoning
Methylmercury poisoning is brain and nervous system damage from the chemical methylmercury.
Causes, incidence, and risk factors
Methylmercury is a type of mercury (“quicksilver”), a metal that is liquid at room temperature. Most compounds containing mercury are poisonous. Methylmercury has been used to preserve seed grain, which is fed to animals. Methylmercury may also form in water when other forms of mercury in the water react with certain bacteria. Methylmercury poisoning has occurred after people have eaten meat from animals fed seed grain or fish from waters contaminated with methylmercury (such as Minamata Bay in Japan).
Signs and tests
Tests will vary depending on the symptoms that occur.
Methylmercury damage is irreversible. Treatment is determined by the severity of the condition and is similar to that given for cerebral palsy. The patient should be removed from the source of exposure. Treatment may involve:
The symptoms are irreversible; however, they do not usually worsen unless there is a new exposure to methylmercury.
Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 1/14/2010