tissue damage resulting from exposure to more than trace amounts of the element mercury or its compounds. Elemental mercury (the silver liquid familiar from thermometers) is the most common occupational source. Exposure typically comes from inhaling mercury vapors. Inorganic salts of mercury (e.g., mercurous chloride, or calomel) are used in some products to inhibit the growth of fungi and bacteria. Organic mercury compounds, especially methylmercury, are more toxic than other forms because they easily cross cell membranes. They are most often ingested in contaminated fish. Mercury poisoning can cause severe neurological and kidney damage. Acute exposure can affect the respiratory and gastrointestinal systems. Organic mercury can cross the blood-brain barrier and cause irreversible nervous system and brain damage, e.g., loss of motor control, numbness in limbs, blindness, and inability to speak. Some studies have connected maternal mercury exposure to fetal damage. Mercury poisoning…