Why mercury is bad

This process continues all the way up the food chain, so that a large fish may contain much more mercury than the fish it has eaten. This does not necessarily make it better to eat smaller fish, however. It is always essential for a person to check the source of their seafood to avoid contaminated fish and shellfish. People worried about their exposure to mercury may want to limit their seafood intake, particularly of fish that are high on the food chain, such as swordfish, shark, white tuna, pike, walleye, and bass.

Pregnant or breast-feeding women may want to avoid or restrict their intake of fish and shellfish, as any mercury they contain can pass to the fetus or infant through the umbilical cord or breast milk. Amalgam fillings, commonly called silver fillings, contain approximately 40 to 50 percent mercury.

Amalgam fillings are not often used now, as there are newer and safer alternatives. Some people choose to replace their amalgam fillings to reduce their long-term exposure to mercury. Mercury poisoning may also be due to direct or environmental exposure. Mercury exposure may come from one or more of the following sources:.

Doctors can usually diagnose mercury poisoning through a physical exam and blood tests. Doctors may ask about any symptoms the person is having, as well as for a general breakdown of their diet. They may also ask questions about the environment the person lives or works in, including whether they live near any factories or work in an industrial plant.

If the doctor suspects mercury poisoning, a blood and or urine mercury test can gauge the levels of mercury in the body. Treatment of mercury poisoning involves eliminating any and all exposure to the metal. Doctors will recommend that the person does not consume any seafood that contains mercury. Mercury poisoning may cause some long-term side effects, which will be treated or managed individually.

Certain types of severe cases of mercury poisoning may require chelation therapy. This is the process of removing mercury from the organs so the body can dispose of it. The drugs used in chelation therapy bind to heavy metals in the bloodstream and are then eliminated in the urine. Chelation therapy comes with its own risks and side effects, so it is crucial to use the medication only when necessary.

Mercury is toxic to humans. There is no standard cure for mercury poisoning, so it is best to avoid exposure to high amounts of mercury when possible. Eliminating risk factors by making changes in the diet and work or living environment may help reduce the levels of mercury in the body. It is essential to consult a doctor at the first sign of mercury poisoning, as it can have long-lasting effects. Parents and caregivers should also be aware of the signs of mercury poisoning in children and call a doctor if a child or infant displays any symptoms.

Author: Healthwise Staff. This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information.

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Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. Updated visitor guidelines. You are here Home » Avoiding Mercury in Fish. Top of the page. Topic Overview What is mercury? Do you need to avoid the mercury found in fish? Environmental Protection Agency EPA advise the following people to avoid eating fish high in mercury and to eat limited amounts of fish and shellfish that are lower in mercury: Women who may become pregnant Pregnant women Nursing mothers Young children If you are concerned about your or your child's mercury level, talk to your doctor or local health department about testing.

How should you change your eating habits to reduce your exposure to mercury in fish? The FDA and EPA recommend that women who may become pregnant, pregnant women, nursing mothers, and young children: footnote 1 Do not eat shark, swordfish, king mackerel, marlin, orange roughy, bigeye tuna, or tilefish from the Gulf of Mexico, because these all contain high levels of mercury. Women who may become pregnant, pregnant women, nursing mothers, and children older than 10 years, should eat between 8 oz g and 12 oz g a week 2 or 3 average meals of a variety of fish and shellfish that are lower in mercury.

Children ages 10 and younger should eat less. Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.

Another commonly eaten fish, albacore "white" tuna, has more mercury than canned light tuna. So when choosing your 2 or 3 meals of fish and shellfish, you may eat up to 4 oz g a week one average meal of albacore tuna. Should a woman who is not planning a pregnancy be concerned? Mercury is a naturally occurring heavy metal. It can build up in the bodies of fish in the form of methylmercury, which is highly toxic.

The amount of mercury in fish and other seafood depends on the species and the levels of pollution in its environment. Another study discovered that one-third of fish caught on the New Jersey shore had mercury levels higher than 0. Overall, larger and longer-lived fish tend to contain the most mercury 4. These include shark, swordfish, fresh tuna , marlin, king mackerel, tilefish from the Gulf of Mexico, and northern pike 5.

Larger fish tend to eat many smaller fish, which contain small amounts of mercury. This process is known as bioaccumulation 6. Mercury levels in fish are measured as parts per million ppm. Here are the average levels in different types of fish and seafood, from highest to lowest 5 :.

Different types of fish and other seafood contain varying amounts of mercury. Larger and longer-lived fish usually contain higher levels. Eating fish and shellfish is a major source of mercury exposure in humans and animals. Exposure — even in small amounts — can cause serious health problems 7 , 8. However, sea plants like algae absorb it. Fish then eat the algae, absorbing and retaining its mercury. Larger, predatory fish then accumulate higher levels from eating smaller fish 9 , In fact, larger, predatory fish may contain mercury concentrations up to 10 times higher than the fish they consume.

This process is called biomagnification One U. Eating a lot of fish — especially larger species — is linked to higher levels of mercury in the body. Exposure to mercury can cause serious health problems