There is no barrier that prohibits mercury from reaching the brain cells. Mercury is extremely toxic and can do serious damage to the brain. The Swedish government has taken steps to ban the use of mercury amalgam fillings. Mercury is a cumulative poison that is retained in the pain center of the brain and the central nervous system. Significant amounts of mercury in your body can produce insomnia, dizziness, fatigue, weakness, depression, memory loss, dermatitis, and hair loss.
High levels can also interfere with enzyme activity, resulting in paralysis and blindness.
Signs indicative of a child suffering from mercury toxicity include behavioral changes, depression, irritability, and hyperactivity. Adults may display these symptoms as well.