Mercury Poisoning

What is mercury?

Mercury is a compound found in rocks in the Earth’s crust. It has a shiny silver appearance, which gives it the nickname “liquid silver.” Mercury is an element on the periodic table with the symbol Hg and the atomic number 80. Mercury is unique because it’s classified as a metal and comes in both liquid and solid forms depending on the temperature.

Mercury has several uses because it’s a conductor. This means that the compound allows electricity and heat to flow through it. For this reason, you’ll find mercury in thermometers, street lights and fluorescent lightbulbs.

What is mercury poisoning?

Mercury is toxic and harmful to the human body. Mercury poisoning occurs when you expose yourself to too much mercury and your body reacts negatively to the compound.

What forms of mercury are poisonous?

There are three different types of mercury that are harmful to the human body including:

• Elemental mercury (liquid mercury, quicksilver): You’ll find elemental mercury in glass thermometers, electrical switches, fluorescent lightbulbs and dental fillings.
• Inorganic mercury: You’ll find inorganic mercury in batteries, certain types of disinfectants and in chemistry labs.
• Organic mercury: You’ll find organic mercury in coal fumes, fish that ate methylmercury (a form of organic mercury) and older antiseptics (germ killers like red mercurochrome).

Who does mercury poisoning affect?

Mercury poisoning can affect anyone who comes into contact with or consumes mercury.

The most severe cases of mercury poisoning affect children and fetuses of pregnant people and people who breastfeed (chestfeed) and consume large amounts of fish with high mercury content.

How common is mercury poisoning?

Mercury poisoning is rare in the United States but can be more common in other countries, especially among mining communities or near seaside towns where food could become contaminated with mercury.

How does mercury poisoning affect my body?

Your body will negatively react if you eat, touch or inhale mercury. Once inside your body, mercury travels to your heart, central nervous system and kidneys. Your body knows that mercury is not supposed to be there, so you’ll experience symptoms, caused by your immune system trying to get the compound out in the same way it would attack bacteria or germs.

What are the signs and symptoms of mercury poisoning?

Symptoms of mercury poisoning are different for each type of mercury and range in severity from person to person.

Elemental mercury poisoning symptoms

Elemental mercury is usually harmless if you touch or swallow it because its slippery texture won’t absorb into your skin or intestines. Elemental mercury is extremely dangerous if you breathe it in and it gets into your lungs. Often, elemental mercury becomes airborne if someone is trying to clean up a mercury spill with a vacuum.

Symptoms of elemental mercury poisoning occur immediately after inhaling the chemical and include:

• Coughing.
• Trouble breathing.
• Metallic taste in your mouth.
• Nausea or vomiting.
• Bleeding or swollen gums.

Inorganic mercury poisoning symptoms

Inorganic mercury is poisonous when swallowed. When the chemical enters your body, it travels through your bloodstream and attacks your brain and kidneys.

Symptoms of inorganic mercury poisoning include:

• Burning sensation in your stomach and/or throat.
• Nausea or vomiting.
• Diarrhea.
• Blood in vomit or stool.
• Urine color changes.

Organic mercury poisoning symptoms

Organic mercury causes symptoms if you inhale it (breathe it in) or touch it. Symptoms don’t occur immediately and usually arise after long periods of contact (could be years or decades) with the compound. Though not always common, being exposed to a large amount of organic mercury at one time can cause symptoms. Symptoms of organic mercury poisoning from long-term exposure include:

• Feeling numb or dull pain in certain parts of your body.
• Tremors (uncontrollable shaking).
• Unsteady walk.
• Double vision or blurry vision; blindness.
• Memory loss.
• Seizures.

People who are pregnant and exposed to large amounts of methylmercury (a type of organic mercury) can cause brain damage to developing fetuses. Most healthcare providers recommend people who are pregnant eat a limited amount of fish or remove fish from their diet, especially swordfish, during their pregnancy.

Long-term organic mercury exposure is deadly. If you frequently come into contact with organic mercury, wear proper personal protective equipment, like a mask and gloves, to reduce your risk of health problems associated with the compound.

What causes mercury poisoning?

Exposure to mercury causes mercury poisoning. Potential ways you could expose your body to mercury include:

• Inhaling mercury vapor (small droplets of mercury that become airborne and enter your lungs).
• Eating fish or seafood that naturally contains large amounts of organic mercury.
• Swallowing mercury.
• Touching liquid mercury.

How is mercury poisoning diagnosed?

Mercury poisoning is most often diagnosed in the emergency room after exposure and experiencing severe symptoms.

Your healthcare provider will diagnose mercury poisoning after a complete medical history and physical examination. Your provider will ask questions about your symptoms like how long you’ve had them and the severity as well as if you’ve been exposed to any chemicals or compounds.

To confirm the diagnosis, your provider will offer several tests to monitor mercury levels in your body including:

• Chest X-ray.
• Urinalysis (24-hour urine collection).
• Bloodwork (complete blood count and a metabolic panel).
• Electrocardiogram.

How is mercury poisoning treated?

In the emergency room, your provider will immediately decontaminate (remove the dangerous substance) from your skin and/or clothing to avoid further exposure. Treatment of your symptoms quickly follows and varies based on the type of mercury exposure.

Treatment focuses on removing mercury from your body and could include receiving:

• Chelation therapy (removing metals from your body) via fluid through an IV.
• Oxygen through a face mask.
• Medicine to treat symptoms.
• Dialysis.
• Surgery to remove mercury.

Often, you’ll need to take chelators (medicine that removes metal from your body) for several weeks to months after mercury exposure to completely remove the chemical from your body.

Even after immediate treatment to remove mercury from your body, damage from the compound could create long-term symptoms that need ongoing treatment.

How can I prevent mercury poisoning?

You can prevent mercury poisoning by:

• Limiting the amount of fish (that contain mercury) you eat.
• Avoid fish (containing mercury) if you’re pregnant or breastfeeding (chestfeeding).
• Wearing personal protective equipment when handling chemicals and compounds.
• Avoid areas in your environment where mercury is present.
• Replacing old amalgam fillings in your teeth with a safer alternative.

If you’re cleaning up a spill that contains mercury, do not vacuum the area to prevent mercury from becoming airborne and entering your lungs. Contact your local or state health department or environmental protection agency to properly clean up any spilled mercury to prevent poisoning.

What can I expect if I have mercury poisoning?

Mercury is dangerous to the human body and your prognosis after exposure depends on the amount of mercury that entered your body and your overall health at the time of exposure.

Some people have very mild symptoms and after treatment to remove the compound from their body, remain in good health after exposure.

More severe cases of mercury exposure lead to a poor prognosis. Elemental mercury, if inhaled, can cause permanent lung damage and potential brain damage. Inorganic mercury can damage kidneys and cause blood loss. Organic mercury can damage your central nervous system (brain and spinal cord). Large amounts of mercury or long-term exposure can lead to death if not treated.

If you’ve been exposed to mercury, contact the poison control center at 1-800-222-1222 and visit the emergency room immediately.

When should I go to ER?

If you experience symptoms of mercury poisoning or are aware that you were exposed to mercury, visit the emergency room immediately.

What questions should I ask my doctor?

• Do I need long-term treatment for mercury poisoning?
• Did the mercury that entered my body leave any damage to my organs?
• What types of food should I avoid if I’m pregnant or breastfeeding?

Can you get mercury poisoning from fish?

Yes, certain types of fish contain methylmercury, which is present in the water where fish live. Methylmercury is a type of organic mercury that is dangerous to the human body if you consume large amounts of it. Limited to moderate amounts of mercury from fish are OK for humans to consume.

Fish and shellfish that have high levels of mercury include:

• Shark.
• King mackerel.
• Swordfish.
• Orange roughy.
• Tuna.
• Pike.
• Walleye.
• Bass.

The FDA recommends that people who are pregnant or breastfeeding (chestfeeding) avoid or limit the amount of fish in their diet that contains high levels of mercury.

Can you get mercury poisoning from amalgam fillings?

Older amalgam dental fillings (silver fillings) contain about 50% mercury (elemental) by weight along with other metals like silver, tin and copper. If you have older amalgam fillings in your mouth, you’re at an increased risk of mercury exposure and poisoning.

Symptoms of mercury exposure from amalgam fillings are the same as symptoms of elemental mercury poisoning, with a metallic taste in your mouth being the primary symptom.

If your fillings aren’t damaged and you don’t have tooth decay underneath your amalgam filling, you don’t have to replace your amalgam fillings with a safer alternative immediately. If you have damaged amalgam fillings, talk with your dentist about replacing those fillings because you’re at a greater risk of mercury exposure.

A note from Cleveland Clinic

Each person’s body will react to mercury exposure differently. Sometimes symptoms will be mild and other times, they could be life-threatening. In any case, if you had mercury exposure, whether it be a small or large amount, contact the national poison control helpline at 1-800-222-1222 to talk with an expert 24 hours a day, seven days a week. You don’t need to be in an emergency to call the helpline to have your questions answered about poisoning and poison prevention.