Vol.3, # 18
May 13, 2006

Q: Is mercury exposure of any kind, but especially in dental fillings, safe? - Layperson

A: No level of mercury exposure is safe. Below certain levels, the damage is acceptable in exchange for the return. A number of investigators have linked occupational mercury exposure to infertility and birth defects in dental personnel. One dentist sued her dental school when she gave birth to an infant with acrodynia (mercury poisoning in children). Apparently, no professor had mentioned during her 4 years of training that her infant could be poisoned in the womb if mercury vapor is inhaled.

The EPA has documented an infant poisoned at 2 ug/m3 and has a current standard of 0.3 ug/m3. Few if any people who have occlusal amalgam fillings breath is below this standard.
The US Public Health Service Agency for Toxic Substances and Disease Registry (ATSDR) has just recommended new standards for the acute exposure to mercury that make it impossible to even mix the components of the filling together much less pack and carve. They determined in November of 1994 that a transient exposure to .020 (ug/m3) was an acute exposure. That means that this level was immediately hazardous to health.
The amount of mercury which is excreted immediately after placement of a number of amalgams is quite large. Studies as early as 1957 using radioactively labeled Mercury 203 found high levels both upon placement and upon removal. High levels were again found when amalgams were removed even when the teeth were extracted. (Frykholm KO: On mercury from dental amalgam. Its toxic and allergic effects and some comments on occupational hygiene. Acta Odont Scand 15:7-108, suppl 22, 1957)

Mercury From Amalgam Is Consumed Daily

Even after the amalgam has set it continues to wear away.

How many micrograms of mercury are consumed daily from the wear of amalgams in the mouth?  (Skare I & Engqvist A. Amalgam restorations - an important source of human exposure of mercury and silver. LÄKARTIDNINGEN 15:1299-1301, 1992)

Excretion of total Hg via feces alone = 263 µg/24 hour. Professor Skare concluded his analysis of fecal mercury with the following statement: "If the average fecal excretion was applied to the entire Swedish population, a total emission of 150 kg/yr (330 lb/year) can be estimated. This is roughly comparable to the yearly mercury leakage from a modern chloralkali plant."

What it the maximum daily intake allowed by the EPA?

10 µg/24 hour for sources other than air. (EPA United States Environmental Protection Agency Office of Health and Environment Assessment, Mercury health effects update Final Report, EPA-600/8-84-019F, 1971, EPA) 

Studies by Clarkson (1998) and the World Health Organization related that one amalgam could release anywhere between 3-18 m gm/day of mercury. And yet, a Canadian conference suggested a Tolerable Daily Intake (TDI) for mercury of only 1 m gm/day for a person weighing about 150 pounds. People with more than 2-3 amalgams, therefore are above the occupationally exposed acceptable levels. In fact, in a study done by Dr. Mark Richardson of Ottawa, Canada at the request of Health and Welfare Canada, it was seen that any more than 3 amalgams in the head of an adult were akin to occupational exposure. In other words, gave off as much mercury as if the person worked in an occupation where they were exposed to mercury on a daily basis.

Dentistry still today claims that spit protects patients from mercury vapor released from dental amalgam. Studies show that the average person makes and swallows 1.5 liters of saliva a day. Yet, if they have as few as 4 amalgams present in their mouth, the average person's saliva is so high in mercury they cannot legally spit into the toilet. Their saliva exceeds the EPA maximum legal municipal discharge standard for mercury. It was interesting to note that the form of the mercury was in was organic. 

The mercury present in the filling is not the only problem with dental fillings. A phenomenon called "electrogalvanism." or electricity in the mouth is also a problem. This phenomenon is created when dissimilar metals are present in the mouth, such as mercury amalgam mixtures and gold, resulting in an electric current being established in the mouth. This phenomenon can cause electrochemical reactions to take place, analogous to the electroplating reactions used in the production of jewelry. Additionally, food and other organic debris trapped in between teeth can be used by bacteria as a food source. One of the byproducts of the bacteria is acid. which can directly affect the teeth as well as contribute to the electrochemical reaction of the fillings. The result is a "battery like" effect. which can release mercury from the fillings and. potentially. cause a direct electrical stimulus to the pituitary and hypothalamus glands.

Studies have linked mercury exposure from the environment with a number and variety of illnesses including Allergies, chronic fatigue, depression. GI disorders, immune systems suppression, periodontal disease, neurological Problems, reproductive disorders, birth defects, kidney disease, heart problems, hypertension, respiratory disorders and skin disease. Mercury can interfere with any process or organ in the body, since it is poisonous to all cells, but it has a marked effect on the immune system [See: Pollard KM. et al Met. IonsBiolSys.34:421(1997)) This has been shown by research indicating the presence of mercury amalgam fillings in the mouth reducing the immune system efficiency by one-third to one-half. If a person has a chronic health problem for which a cause has not be found and mercury fillings are present in the mouth. mercury toxicity may be a contributing factor.

To test whether an individual's mercury levels may be the cause of the problem. one can use the compound 2.3-Dimercaptosuccinic Acid~(DMSA) to chelate (bind to) mercury in a provocative oral dose. Analyzing mercury in a collection of urine over the subsequent six  hours can give an indication of the mercury burden of the body tissues.Additionally. chronic exposure to mercury can be detected in the hair [see Katz SA.KatzRB.J Appl. Tox.12.79(1992)]

The Chewing Gum Connection

Most people don't realize the grave danger that exists in the simple and seemingly innocent act of chewing gum. However, studies have shown that gum chewing greatly increases the exposure to mercury.

One recent study found that heavy gum chewers had twice the amount of mercury in their blood and three times the level in their urine and breath exhalation than did infrequent chewers. And if you were to compare with those who don't chew gum at all, the difference would likely be even greater.

This is very important, as those most vulnerable, such as pregnant women, may be unknowingly exposing their unborn children to mercury which is a know teratogen (substance that causes birth defects).

Mercury In Fish From Environmental Contamination Damaging Newborns

A recent CDC report reveals that nearly one in 10 US women could have levels of mercury in their blood that are close to hazardous.

Exposure to dangerous levels of mercury can result in permanent damage to the brain and kidney. Exposure is particularly risky for women of childbearing age, because a fetus is highly susceptible to adverse effects.

Combustion in power plants of coal containing mercury is the major source of environmental pollution.

40 Tons of Mercury are released into the US EVERY year by this method.

Mercury pollution from coal-fired power plants moves through the air, is deposited in water and finds its way into fish, accumulating especially in fish that are higher up the food chain. Fish like tuna, sea bass, marlin and halibut show some of the worst contamination, but dozens of species and thousands of water bodies have been seriously polluted.

As a result, women who eat a lot of fish during pregnancy, or even as little as a single serving of a highly contaminated fish, can expose their developing child to excessive levels of mercury. The toxic metal can cross the placenta to harm the rapidly developing nervous system, including the brain.

About 20,000 children this year will be exposed to a dose of methylmercury that increases the risk of adverse neurological effects for the entire pregnancy.

According to Public Citizen, "It is irrefutable that power plant emissions contribute to all sorts of environmental problems -- smog, acid rain, mercury poisoning of rivers and streams, radioactive waste -- all of which lead to climate change, air pollution, damaged crops, dying forests, and health problems like emphysema, lung disease, cancer and premature death."

By age two, American children have received 237 micrograms of mercury through vaccines alone, which far exceeds current EPA "safe" levels of .1 mcg/kg. per day. That's one-tenth of a microgram, not one microgram.

This means that children are getting many times the amount of mercury that the EPA deems safe from the shots that are mandated by the government.

The figure of one autistic infant for every 150 is now widely documented.


  • Dental Amalgam contains about 50% Mercury.
  • Mercury has been scientifically demonstrated to be more toxic than Lead, Cadmium or even Arsenic.
  • Mercury leaves dental amalgam continuously throughout the lifetime of the filling.
  • Mercury vapour is the main way that mercury comes out of amalgam.
  • Mercury vapour is absorbed at a rate of 80% through the lungs into the arterial blood.
  • Mercury kills cells.
  • There is NO harmless level of Mercury Vapour Exposure.
  • Mercury from mercury fillings binds to sulphydryl groups. These exist in almost every enzymatic process in the body. Mercury from amalgam has the potential to disturb all metabolic processes.
  • Mercury from amalgam is transported freely via the blood.
  • Mercury vapour is absorbed directly into the brain.
  • Mercury from amalgam will result in a slow build up of mercury in body tissues.
  • Mercury crosses the blood brain barrier.
  • Mercury is implicated in Alzheimer's Disease.
  • Mercury from amalgam is stored in the foetus and infant before the mother and may be part of the reason for children getting cancer.
  • Mercury from amalgam is stored in the breast milk and the foetus up to 8 times more than the mother's tissues.
  • Mercury crosses the placenta.
  • Mercury crosses into breast milk.
  • Mercury will severely reduce reproductive function.
  • Mercury rapidly depletes the immune system.
  • Mercury will induce a number of Auto Immune Diseases.
  • Mercury will cause an increase in number and severity of all allergies.
  • Mercury from amalgam is stored principally in the kidneys, liver and brain.
  • Mercury from amalgam causes kidney damage (shown in animal experiments).
  • Mercury from amalgam causes a 50% reduction in Kidney filtration, as shown in a study of sheep after amalgam placement.
  • After chewing, Mercury vapour levels will remain raised for at least another 90 minutes.
  • Mercury from amalgam will migrate through the tooth.
  • This rate of migration is increased if a gold crown is placed over a tooth filled with amalgam.
  • Teeth are living tissues and are a part of our bodies.
  • Teeth have a massive communication via blood, lymph and nerves with the rest of the body.
  • Mercury from amalgam is absorbed into the body at a rate of 3 to 17 mcg / day (WHO 1991 Criteria 118)
  • Mercury is transported along nerve fibres.
  • Mercury form amalgam may be stored in every cell in the body. Each area affected will produce its own set of symptoms.
  • Mercury binds to haemoglobin in the red blood cell thus reducing oxygen carrying capacity.
  • Mercury damages blood vessels, thereby reducing blood supply to the tissues.
  • Amalgam fillings produce electrical currents which are no doubt injurious to health. These currents are measurable in Micro Amps. The Central Nervous System and Brain operate in the range of Nano-Amps, which are 1,000 times less than a Micro Amp.
  • Dissimilar metals in the mouth, such as gold and amalgam, produce higher electrical currents.
  • Brain levels of mercury are in a direct linear proportion to the number of surfaces of amalgam fillings in the mouth.
  • Mercury will cause single strand breaks in DNA .
  • Mercury levels in the blood can NOT be assessed by blood or urine levels.
  • Dental personnel are severely affected by exposure to mercury.
  • Below is a chart of statistics from the World Health Organization(WHO):
    World Health Organization Figures

    Average Human Daily Dose of Mercury

    Dental amalgam:  
    Fish and Seafood:  
    Other food:  
    Air & Water:  
    3.0-17.0  µg/day (hg vapor)
    2.3          µg/day (methylmercury)
    0.3          µg/day (inorganic hg)
    negligible traces
    (World Health Organization, Environmental Health Criteria 118: Inorganic Mercury, Geneva, 1991.)
    If you have fillings(especially more than 3), then consider getting the fillings replaced with other composites.
    There are no long term studies on exposure to low levels of mercury, but the effects of even small amounts is cumulative and will eventually produce damage. Mercury is also stored in the fat(possibly large fat loss from dieting can release more mercury into the blood). If there is no need to be exposed to mercury, than avoid it rather than take a risk.


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    DISCLAIMER:  The information in this column, is NOT intended to diagnose and/or treat any health related issues and is provided solely for informational purposes only. Consult the appropriate healthcare professional before making any changes to your healthcare regime. Even what may seem like simple changes in the diet for example, can interact with, and alter, the efficiency of medications and/or the body's response to the medications. Many herbs and supplements exert powerful medicinal effects. Neither the author, nor the website designers, assume any responsibility for the reader's use or misuse of this information.

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