Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If heated, it is a colorless, odorless gas. It also combines with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used in glass thermometers, silver dental fillings, and button batteries. Mercury salts may be used in skin creams and ointments. It's also used in many industries.

Mercury in the air settles into water. It can pass through the food chain and build up in fish, shellfish, and animals that eat fish. The nervous system is sensitive to all forms of mercury. Exposure to high levels can damage the brain and kidneys. Pregnant women can pass the mercury in their bodies to their babies.

It is important to protect your family from mercury exposure:

• Carefully handle and dispose of products that contain mercury
• Limit your consumption of fish with higher levels of mercury

Mercury is a naturally occurring element. Its distribution in the environment is the result of both natural and man-made processes. People don’t usually come in contact with all forms of mercury. There are two general categories of mercury:

1. Inorganic mercury – This is an ionized form of mercury that combines with other chemical elements to create salt forms.These salts have been used in medicines and cosmetics as well as industrial applications.
   • Elemental mercury vapor (Hg0) from metallic mercury or liquid mercury is the elemental or pure form of mercury; i.e., it is not combined with other elements. It is the primary form of mercury released into the air by natural processes, such as volcanic activity. It is used to measure pressure and temperature, as well as in electric switches. Elemental mercury is used in a number of industries, including the chloralkali and formaldehyde synthesis processes. It is generally the form of mercury that falls from the atmosphere and is turned into methylmercury by microorganisms.
2. Organic mercury – Microorganisms in the environment can convert inorganic mercury to organic forms, most commonly methylmercury.
   • Methylmercury is the form of mercury that the general population is most likely to encounter. This form can build up in the environment and accumulate in certain freshwater and saltwater fish, and marine mammals. Fish eating birds also accumulate methylmercury primarily, and are another way that people can come in contact with mercury.
   • Ethylmercury is an organic form of mercury found in some medical preservatives. Also used in some parts of the world as an antifungal agent in grains.

What to Do if You Have Mercury in Your Home

Many people have found containers of elemental or metallic mercury in their homes. If you have metallic mercury in your home, you need to exercise extreme caution with it and package it to prevent any leaks or spills. See the next two sections of this page to find how to package, transport and dispose of mercury.

• Packaging mercury for storage and transportation
• Recycling and disposal options

Packaging Mercury for Storage and Transportation

• Place all mercury-containing products or containers of mercury inside a larger container with a tight fitting lid.
• Place kitty litter or oil-absorbent matter around the product to protect it from breaking or sudden shocks.
• Clearly label storage container as "Mercury - DO NOT OPEN."
• If you must wait for a hazardous waste collection day, store products safely in their original containers with the labels intact, and keep them out of reach of children and pets.
• Transport containers to a household hazardous collection center in a cardboard box. Secure the containers so that they do not tip over, and to minimize shifting or sliding during sudden stops or turns.
• Transport containers in the back of a pick-up truck or in your car's trunk. If you must transport in the passenger compartment, make sure there is adequate ventilation.

Recycling and Disposal Options

Many states and local agencies have developed collection/exchange programs for mercury-containing devices such as thermometers, manometers, and thermostats. Some counties and cities also have household hazardous waste collection programs. For information about these programs, contact your local officials to find out when and where a collection will be held in your area.

Mercury is a neurotoxin. How someone's health may be affected by an exposure to mercury depends on a number of factors:

• The form of mercury (for example, methylmercury or elemental (metallic) mercury);
• The amount of mercury in the exposure;
• The age of the person exposed (unborn infants are the most vulnerable);
• How long the exposure lasts;
• How the person is exposed -- breathing, eating, skin contact, etc.; and
• The health of the person exposed.

The effects of mercury exposure can be very severe, subtle, or may not occur at all, depending on the factors above. Anyone with concerns about mercury exposure can consult their physician and/or their poison control center at 1-800-222-1222.

Note on Mercury and Cancer: No human data currently ties mercury exposure to cancer, but the data available are limited. In very high doses, some forms of mercury have caused increases in several types of tumors in rats and mice. When EPA published its Cancer Guidelines in 2005, the Agency concluded that environmental exposures to inorganic mercury and methylmercury are not likely to cause cancer in humans.

Methylmercury

Effects on People of All Ages

Exposure to methylmercury most commonly occurs when people eat kinds of fish and shellfish that have high levels of methylmercury in their tissues. Almost all people have at least small amounts of methylmercury in their bodies, reflecting the widespread presence of methylmercury in the environment. U.S. Centers for Disease Control and Prevention (CDC) show that most people have blood mercury levels below levels associated with possible health effects. Methylmercury, however, is a powerful neurotoxin, and people exposed to high levels may experience adverse health effects. If you are concerned about your exposure to methylmercury, you should consult your physician.

Possible symptoms of methylmercury poisoning may include:

• Loss of peripheral vision;
• "Pins and needles" feelings, usually in the hands, feet, and around the mouth;
• Lack of coordination of movements;
• Impairment of speech, hearing, walking; and/or
• Muscle weakness

Effects on Infants and Children

Infants in the womb can be exposed to methylmercury when their mothers eat fish and shellfish that contain methylmercury. This exposure can adversely affect unborn infants' growing brains and nervous systems. These systems may be more vulnerable to methylmercury than the brains and nervous systems of adults are.Children exposed to methylmercury while they are in the womb can have impacts to their cognitive thinking, memory, attention, language, fine motor skills, and visual spatial skills.

Elemental (Metallic) Mercury

Exposures to metallic mercury most often occur when metallic mercury is spilled, or when products that contain metallic mercury break, so that mercury is exposed to the air. If you are concerned about your exposure to metallic mercury, you should consult your physician.

Metallic mercury mainly causes health effects when inhaled as a vapor where it can be absorbed through the lungs. Symptoms of prolonged and/or acute exposures include:

• Tremors;
• Emotional changes (such as mood swings, irritability, nervousness, excessive shyness);
• Insomnia;
• Neuromuscular changes (such as weakness, muscle atrophy, twitching);
• Headaches;
• Disturbances in sensations;
• Changes in nerve responses; and/or
• Poor performance on tests of mental function.

Higher exposures may also cause kidney effects, respiratory failure and death.

Note that metallic mercury vapor is not the same as methylmercury.

Other Mercury Compounds

High exposure to inorganic mercury may result in damage to the gastrointestinal tract, the nervous system, and the kidneys. Both inorganic and organic mercury are absorbed through the gastrointestinal tract and affect other systems through this route. Symptoms of high exposures to inorganic mercury include:

• Skin rashes and dermatitis;
• Mood swings;
• Memory loss;
• Mental disturbances; and/or
• Muscle weakness.

Some people who drink water containing inorganic mercury substantially in excess of the maximum contaminant level (MCL) for many years could experience kidney damage. If you are concerned about an exposure to inorganic mercury, you should consult your physician.

Breastfeeding mothers should minimize exposure to mercury in their diets, at home, and at work.

Mercury is a naturally-occurring element in the environment and is also released into the environment through human activities such as burning coal and oil. Mercury collects in streams, lakes, and oceans, where fish and other animals are exposed. Small amounts of mercury are also used in making common household items like fluorescent bulbs and some thermometers. People who work in recycling plants, who manufacture items with mercury, and who handle dental amalgam might have some mercury exposure on the job.

How might mercury affect breastfeeding mothers and babies?

Mercury can pass from a mother to her baby through the placenta during pregnancy and, in smaller amounts, through breast milk after birth. Exposure to mercury can affect the infant’s brain and nervous system development during pregnancy and after birth.

How much and what types of fish are recommended for breastfeeding women to consume?

Although mercury naturally occurs throughout the environment, the mother’s diet is the primary source of mercury exposure for most breastfed infants before they are introduced to complementary foods. Most fish contain some level of mercury. When a mother eats fish, the mercury in the fish can be passed into her breast milk. However, the benefits of breastfeeding may be greater than the possible adverse effects of exposure to mercury through breast milk.

Although fish remains an excellent source of protein and essential vitamins and minerals for breastfeeding women, some care must be taken in how much and what kind to eat. The U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA) have issued fish consumption guidance for pregnant and breastfeeding women and young children:

• Eat a variety of fish.
• If you eat fish caught by family or friends, check for fish advisories. If there is no advisory, eat only one serving and no other fish that week.
• Try to avoid eating the “Choices to Avoid” fish or feeding them to children.

For adults:

• 1 serving = 4 ounces of fish, measured before cooking. Eat 2 to 3 servings (between 8 and 12 ounces) of fish a week from the “Best Choices” list OR 1 serving (4 ounces) from the “Good Choices” list on this chart.

How can breastfeeding mothers and their families protect themselves from mercury at home?

Handling an intact lightbulb or thermometer that contains mercury does not cause mercury exposure. If a mercury-containing lightbulb or thermometer breaks, however, it can spill mercury onto surfaces and release mercury vapors into the air. If this happens, families should be advised to follow the EPA instructions on safe clean-up of a broken mercury-containing lightbulb or broken mercury thermometer.

How can breastfeeding mothers reduce their exposure to mercury at work?

Women who are concerned about mercury exposure at work should be advised to talk to their supervisor or safety officer to discuss ways to avoid or reduce exposure to mercury. Information on how to reduce mercury exposure in different jobs is available from the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA).

Emissions of Mercury into the Air

Mercury becomes a problem for the environment when it it is released from rock and ends up in the atmosphere and in water. These releases can happen naturally. Both volcanoes and forest fires send mercury into the atmosphere.

Human activities, however, are responsible for much of the mercury that is released into the environment. The burning of coal, oil and wood as fuel can cause mercury to become airborne, as can burning wastes that contain mercury.

This airborne mercury can fall to the ground in raindrops, in dust, or simply due to gravity (known as “air deposition”). The amount of mercury deposited in a given area depends on how much mercury is released from local, regional, national, and international sources.

Emissions from Power Plants

Since mercury occurs naturally in coal and other fossil fuels, when people burn these fuels for energy, the mercury becomes airborne and goes into the atmosphere. In the United States, power plants that burn coal to create electricity are the largest source of emissions; they account for about 44 percent of all manmade mercury emissions.

Other Causes of Mercury Air Emissions

• Burning oil that contains mercury
• Burning wood that contains mercury
• Burning mercury-containing wastes, including
  • Wastes from the manufacture of Portland cement
  • Consumer products that contain mercury, like electronic devices, batteries, light bulbs and thermometers, that are thrown into garbage that is incinerated
• Using certain technologies to produce chlorine
• Breaking products that contain mercury
• Burning iron ore, coke and limestone in electric arc furnaces used to produce steel
• Using coal-fired boilers in many industries to generate forms of thermal heat like steam

The burning of municipal and medical waste was once a major source of mercury emissions. A reduction in the use of mercury along with state and federal regulations, however, has led to a decrease in emissions from this source by over 95%.

Trends in Air Emissions

Every year, industrial and commercial facilities are required to report their releases of chemicals through EPA's Toxics Release Inventory (TRI) Program.

Mercury Emissions around the Globe

What happens to mercury after it is emitted depends on several factors:

• The form of mercury emitted
• The location of the emission source
• How high above the landscape the mercury is released (for example, the height of a power-plant stack)
• The surrounding terrain
• The weather

Depending on these factors, mercury in the atmosphere can be transported over a range of distances -- anywhere from a few feet from its source, to halfway around the globe -- before it is deposited in soil or water. Mercury that remains in the air for prolonged periods of time and travels across continents is said to be in the "global cycle."

One major source of mercury emissions outside of the U.S. is small-scale gold mining that occurs in many countries.

Common Exposures to Mercury

The main way that people are exposed to mercury is by eating fish and shellfish that have high levels of methylmercury, a highly toxic form of mercury, in their tissues. A less common way people are exposed to mercury is breathing mercury vapor. This can happen when mercury is released from a container, or from a product or device that breaks. If the mercury is not immediately contained or cleaned up, it can evaporate, becoming an invisible, odorless, toxic vapor.

Health Effects Associated with Exposures to Mercury

Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system of people of all ages. High levels of methylmercury in the bloodstream of babies developing in the womb and young children may harm their developing nervous systems, affecting their ability to think and learn.

Ecological Effects of Mercury Exposure

Birds and mammals that eat fish have more exposures to methylmercury than other animals in water ecosystems. Predators that eat these birds and mammals are also at risk. Methylmercury has been found in eagles, otters, and endangered Florida panthers. At high levels of exposure, methylmercury's harmful effects on these animals include:

• Death
• Reduced reproduction
• Slower growth and development
• Abnormal behavior

Consumer Products that Traditionally Contain Mercury

• Some batteries
• Fluorescent light bulbs, including compact fluorescents (CFLs)
• Many types of thermometers
• Thermostats
• Amalgam in dental fillings
• Thimerosal in vaccines
• Automotive switches

Mercury poisoning is a condition that occurs in people who are exposed to toxic levels of the element, mercury. There are three different forms of mercury that can cause health problems:

• Elemental mercury (also known as liquid mercury or quicksilver) can be found in glass thermometers, electrical switches, dental fillings and fluorescent light bulbs. This form of mercury is generally only harmful when small droplets become airborne and are inhaled. If this occurs, signs and symptoms of poisoning may include metallic taste, vomiting, difficulty breathing, coughing, and/or swollen, bleeding gums. In severe cases, long-term brain damage, permanent lung damage and even death may occur.
• Inorganic mercury is found in batteries, chemistry labs, and some disinfectants. This form of mercury is harmful when swallowed. Signs and symptoms of inorganic mercury poisoning vary based on the amount consumed, but may include burning in the stomach and throat; vomiting; and/or bloody diarrhea. Inorganic mercury can also affect the kidneys and brain if it enters the blood stream.
• Organic mercury can be found in fish. Some organisms convert fumes from burning coal into organic mercury. This form of mercury is harmful if inhaled, eaten, or placed on the skin for long periods of time. Long-term exposure to organic mercury may result in skin numbness or pain; tremor; inability to walk well; blindness; double vision; memory problems; seizures; or even death.

Treatment is generally supportive and based on the signs and symptoms present in each person. Medications called chelators, which remove mercury and heavy metals from the body, are generally prescribed.

Whatever your complexion, it’s important to use products that will help your skin and not damage it. But as you wade through the beauty aisles, the U.S. Food and Drug Administration cautions that you should avoid skin creams, beauty and antiseptic soaps, and lotions that contain mercury.

How will you know if mercury is in the cosmetic, especially one that’s marketed as “anti-aging” or “skin lightening”? Check the label. If the words “mercurous chloride,” “calomel,” “mercuric,” “mercurio,” or “mercury” are listed on the label, mercury’ is in it—and you should stop using the product immediately.

The products are usually marketed as skin lighteners and anti-aging treatments that remove age spots, freckles, blemishes, and wrinkles. Adolescents may use these products as acne treatments.

These products usually are manufactured abroad and sold illegally in the United States, often in shops catering to the Latino, Asian, African, or Middle Eastern communities. They are promoted online on social media sites and sold through mobile apps. Consumers may also have bought them in another country and brought them back to the U.S. for personal use.

If the ingredients aren’t listed and there is no product label, don’t assume it’s fine. Federal law requires that ingredients be listed on the label of any cosmetic or nonprescription drug, so do not use a product that doesn’t have a label. In addition, don’t use drugs or cosmetics labeled in languages other than English unless English labeling is also provided. That’s also a sign that the product may be marketed illegally.

Even though these products are often promoted as cosmetics, they also may be unapproved new drugs under the law. FDA does not allow mercury in drugs or in cosmetics, except under very specific conditions where there are no other safe and effective preservatives available – conditions that these products do not meet.

Sellers and distributors who market mercury-containing skin whitening or lightening creams in the U.S. may be subject to enforcement action, including seizure of products, injunctions, and, in some situations, criminal prosecution.

Dangers of Mercury

Exposure to mercury can have serious health consequences. The danger isn’t just to people who use mercury-containing products but also to their families. When you use these products your family might breathe mercury vapors or might become exposed by using things like washcloths or towels contaminated with mercury.

Some people – including pregnant women, nursing babies and young children – are especially vulnerable to mercury toxicity. Babies may be particularly sensitive to the harm mercury can cause to their developing brains and nervous systems. Newborns who nurse are vulnerable because mercury is passed into breast milk.

Signs and Symptoms of Mercury Poisoning

• irritability
• shyness
• tremors
• changes in vision or hearing
• memory problems
• depression
• numbness and tingling in hands, feet or around mouth

Source: Agency for Toxic Substances and Disease Registry

Tracking Skin Products Containing Mercury

In the past few years, FDA and state health officials have discovered numerous products that contain mercury, and there have been cases in which people exposed to such products have had mercury poisoning or elevated levels of mercury in their bodies. FDA has an import alert in place that lets our field staff know that the agency has enough evidence or other information to refuse admission of shipments of mercury-containing skin products.

But this is only a partial solution.

Many of these products are coming into the country through illegal channels. That’s why it’s so important for consumers and sellers to know about the dangers of possible mercury poisoning associated with the use of these skin products.

How to Protect Yourself

Thoroughly wash your hands and other parts of your body that have come in contact with products that contain mercury.

Contact your health care professional or a medical care clinic for advice. If you have questions, call your health care professional or the Poison Center at 1-800-222-1222; it is open 24 hours a day.

Before throwing out a product that may contain mercury, seal it in a plastic bag or leak-proof container. Check with your local environmental, health, or solid waste agency for disposal instructions. Some communities have special collections or other options for disposing of hazardous household waste.

What is mercury?

Mercury is a naturally occurring metal which has several forms. The metallic mercury is a shiny, silver-white, odorless liquid. If heated, it is a colorless, odorless gas.

Mercury combines with other elements, such as chlorine, sulfur, or oxygen, to form inorganic mercury compounds or "salts," which are usually white powders or crystals. Mercury also combines with carbon to make organic mercury compounds. The most common one, methylmercury, is produced mainly by microscopic organisms in the water and soil. More mercury in the environment can increase the amounts of methylmercury that these small organisms make.

Metallic mercury is used to produce chlorine gas and caustic soda, and is also used in thermometers, dental fillings, and batteries. Mercury salts are sometimes used in skin lightening creams and as antiseptic creams and ointments.

What happens to mercury when it enters the environment?

• Inorganic mercury (metallic mercury and inorganic mercury compounds) enters the air from mining ore deposits, burning coal and waste, and from manufacturing plants.
• It enters the water or soil from natural deposits, disposal of wastes, and volcanic activity.
• Methylmercury may be formed in water and soil by small organisms called bacteria.
• Methylmercury builds up in the tissues of fish. Larger and older fish tend to have the highest levels of mercury.

How might I be exposed to mercury?

• Eating fish or shellfish contaminated with methylmercury.
• Breathing vapors in air from spills, incinerators, and industries that burn mercury-containing fuels.
• Release of mercury from dental work and medical treatments.
• Breathing contaminated workplace air or skin contact during use in the workplace.
• Practicing rituals that include mercury.

How much mercury spilled in a room will make air in the room unsafe?

Any amount of mercury spilled indoors can be hazardous. The more mercury is spilled, the more its vapor will build up in air and the more hazardous it will be. Even a small spill, such as from a broken thermometer, can produce hazardous amounts of vapor if a room is small enough, warm enough and people spend a good deal of time there, as in a small bedroom

How can mercury affect my health?

The nervous system is very sensitive to all forms of mercury. Methylmercury and metallic mercury vapors are more harmful than other forms, because more mercury in these forms reaches the brain. Exposure to high levels of metallic, inorganic, or organic mercury can permanently damage the brain, kidneys, and developing fetus. 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 vapors may cause effects including lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation.

How likely is mercury to cause cancer?

There are inadequate human cancer data available for all forms of mercury. Mercuric chloride has caused increases in several types of tumors in rats and mice, and methylmercury has caused kidney tumors in male mice. The EPA has determined that mercuric chloride and methylmercury are possible human carcinogens.

How does mercury affect children?

Very young children are more sensitive to mercury than adults. Mercury in the mother's body passes to the fetus and may accumulate there. It can also can pass to a nursing infant through breast milk. However, the benefits of breast feeding may be greater than the possible adverse effects of mercury in breast milk.

Mercury's harmful effects that may be passed from the mother to the fetus include brain damage, mental retardation, incoordination, blindness, seizures, and inability to speak. Children poisoned by mercury may develop problems of their nervous and digestive systems, and kidney damage.

How can families reduce the risk of exposure to mercury?

Carefully handle and dispose of products that contain mercury, such as thermometers or fluorescent light bulbs. Do not vacuum up spilled mercury, because it will vaporize and increase exposure. If a large amount of mercury has been spilled, contact your health department. Teach children not to play with shiny, silver liquids.

Properly dispose of older medicines that contain mercury. Keep all mercury-containing medicines away from children.

Pregnant women and children should keep away from rooms where liquid mercury has been used.

Learn about wildlife and fish advisories in your area from your public health or natural resources department.

Is there a medical test to show whether I've been exposed to mercury?

Tests are available to measure mercury levels in the body. Blood or urine samples are used to test for exposure to metallic mercury and to inorganic forms of mercury. Mercury in whole blood or in scalp hair is measured to determine exposure to methylmercury. Your doctor can take samples and send them to a testing laboratory.

Has the federal government made recommendations to protect human health?

The EPA has set a limit of 2 parts of mercury per billion parts of drinking water (2 ppb).

The Food and Drug Administration (FDA) has set a maximum permissible level of 1 part of methylmercury in a million parts of seafood (1 ppm).

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.