Based on these results, the EPA determined that mercuric chloride and methylmercury are potential human carcinogens. In laboratory testing, however, mercuric chloride has been shown to cause increases in several types of tumors in rats and mice, and methylmercury has caused kidney tumors in male mice. There are insufficient human cancer data available to implicate all forms of mercury as a causal factor. Children poisoned by mercury exposure after birth may develop problems of their nervous and digestive systems, and suffer kidney damage. Mercury’s harmful effects that may be passed from the mother to her baby include brain damage, mental retardation, blindness, seizures, muteness, and lack of coordination. Very young children are more sensitive to mercury than adults. While the benefits of breast-feeding may be greater than the possible adverse effects, mercury can pass to a nursing infant through breast milk. Mercury in the mother’s body passes to the fetus and may accumulate there. Health Effects During and After Pregnancy: Long-term mercury exposure effects on brain functioning may result in irritability, shyness, tremors, changes in vision or hearing, and memory problems. Short-term exposure to high levels of metallic mercury Mercury vapors may cause effects including lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation. Exposure to high levels of metallic, inorganic, or organic mercury can permanently damage the brain, kidneys, and developing fetus. Methylmercury and metallic mercury vapors are more harmful than other forms, because more mercury in these forms reaches the brain. The nervous system is very sensitive to all forms of mercury. The Occupational Safety and Health Administration (OSHA) has set limits of 0.1 milligram of organic mercury per cubic meter of workplace air (0.1 mg/m3) and 0.05 mg/m3 of metallic mercury vapor for 8-hour shifts and 40-hour work weeks. The FDA set a maximum permissible level of 1 part per million (ppm) of methylmercury for seafood products sold though interstate commerce. The Federal Government established strict guidelines for mercury exposure: The EPA has set a limit of 2 parts of mercury per billion parts of drinking water (2 ppb). Children can be exposed to Thimerosal, a vaccine preservative containing mercury, if they receive multiple doses of vaccines with total amounts of mercury levels exceeding federal guidelines. Workers can breathe mercury-contaminated air or come into direct skin contact with mercury during uses in the workplace (dental, health services, chemical, and other industries that use mercury). Mercury can leach into the body from dental amalgam fillings. High levels of mercury have also been found in oysters and clams. Larger and older fish, most notably – swordfish, tend to have the highest levels of mercury. Methylmercury builds up in the tissues of fish and shellfish. Methylmercury may be formed in water and soil by small organisms called bacteria. Mercury enters the water or soil from natural deposits, disposal of wastes, spills, and volcanic activity. Humans can be exposed to mercury through several different routes: Inorganic mercury (metallic mercury and inorganic mercury compounds) enters the air as pollution from mining ore deposits, coal fires, open burning of waste, spills, incinerators, and industries using mercury-containing fuels. Common industrial sources of inorganic mercury compounds include oil refining, mining ore deposits, incineration, and waste disposal by open burning and coal-fired power plants. Salts formed from elemental mercury were formerly used in mildew-resistant paints, agricultural fungicides, skin-lightening creams, antiseptic creams and ointments. Metallic mercury is also still commonly used for dental amalgam fillings. Metallic mercury is used to produce chlorine gas and caustic soda, and it is also used in thermometers, barometers, pressure sensors, manometers (“silent” electrical switching devices), mirrors, fluorescent light bulbs, battery lamps and batteries. Fact Sheet Continues Below What is it used for?
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