One of the best reviews on the topic regarding mercury exposure from dental fillings is Mercury exposure from ‘silver’ tooth fillings: emerging evidence questions a traditional dental paradigm. FASEB J. 9: 504-508 (1995) by Lorscheider, FL, Vimy, MJ, Summers, AO. FASEB is the Federation of American Societies for Experimental Biology; their journal is one of the world’s highest-rated scientific sources. We encourage our visitors to review this important study.
In 1991, the World Health Organization acknowledged that the predominant source of mercury exposure to humans is from fillings. The best-accepted reference on daily absorbed mercury comes from the World Health Organization proceedings in 1991. The report was from a meeting of toxicologists and environmental specialists.2
| Mercury Source|| Daily Exposure|| Form of Mercury|
| Dental Amalgam|| 3.0-17.0 µg/day|| Hg vapor|
| Fish and Seafood|| 2.3 µg/day|| methylmercury|
| Other Food|| 0.3 µg/day|| inorganic Hg|
| Air & Water|| Negligible traces|| |
In recent years there has been much press about the harmful effects of mercury exposure from fish; the media has conveniently ignored the fact that exposure from fish is mute compared to daily exposure from fillings as demonstrated in the chart above. Putting the amount of mercury present in an average filling into perspective, a four-foot fluorescent bulb, which should be disposed of as hazardous waste, has approximately 22 milligrams of mercury. The average dental amalgam filling contains about 1,000 milligrams of mercury. Many studies suggest that the mercury exposure from fillings may be even greater than what the WHO has determined, particularly when more than one metal is present in the mouth and the resulting galvanic current causes even faster corrosion of the mercury fillings. One study found compelling evidence that 65% of the mercury that is in an amalgam when it was first prepared leaches out in under 10 years. In this study, approximately 30 micrograms of mercury were calculated to be released per day. Over the 9+ year life of the amalgam, 101.2 mg of mercury left the filling. The study also concluded that a 1 microamp current between a gold alloy crown or bridge and an amalgam filling that are in continuous contact for 10 years will release 90 micrograms of mercury per day!13
In the late 1980’s, Murray Vimy and Fritz Lorscheider along with the University of Calgary placed twelve occlusal fillings tagged with radioactive mercury in the mouth of a sheep4. After twenty-nine days the sheep was killed and the portions of the teeth containing the fillings were removed. The sheep was placed in a full body gamma ray scanner. The results were dramatic. The radioactive mercury from the fillings had translocated into several organs and into the jawbone. In their experiment, the organs that accumulated the greatest amount of mercury were the kidneys, liver, and stomach. It is interesting to note that only small traces of mercury were found in the urine, demonstrating the inadequacy of a urine sample as an indicator of mercury storage in the body. Further sheep studies were conducted all showing similar results5. Sheep were initially chosen for the experiment because of the extensive amount they chew. If no mercury exposure from fillings would be found in sheep, then it would be unlikely to be found in humans. After the results of the sheep study, the same experiment was repeated using a monkey6 (since monkeys have eating and chewing habits similar to humans). The results were nearly identical to that of the sheep. In the monkeys, placement of amalgam fillings impaired kidney function by 60% in 60 days. The same monkey experiment was also conducted and confirmed in Denmark7.
EFFECTS ON FERTILITY
The vapor from mercury fillings easily passes to all the tissues and organs, including those of reproduction. With regards to the male reproductive system, mercury has an affinity for sperm. Mercury and other heavy metals are found in male ejaculate and seminal fluid, with the heaviest amount in the sperm. There are two ways mercury in male reproductive fluids may be a problem with respect to infertility. 1) Women may be hypersensitive or allergic to mercury and thus have antibodies to mercury which will then react with the sperm and kill them. 2) Sperm with low motility are low in zinc and manganese; these are needed in the enzyme systems necessary for sperm motility. Mercury inhibits zinc and manganese. Thus there can be an indirect effect of mercury on sperm. Further, selenium is also involved in sperm motility as well as in the normal development of sperm. Selenium has a very high affinity for mercury and is one of the body’s natural protectors against mercury; if the selenium is tied up with mercury it is not available for other important functions like healthy sperm. Mercury also inhibits the synthesis of DNA in sperm forming cells. In fact, mercury was once used in contraceptive gels because it kills sperm.
Mercury vapor from fillings has no electrical charge – it is elemental mercury. It goes to the blood and in one minute circulates to the whole body. Having no charge it easily passes to various tissues and organs and then becomes charged. It then binds to proteins and is thus called inorganic mercury. Mercury can destroy the biological function of any protein it binds to. According to the Center for Disease Control, one in twelve women of child-bearing age already have unsafe blood levels of mercury. This is scary because blood is not even a good indicator of mercury – it is when it leaves the blood and binds to proteins that it becomes a problem.
With the intricate balance of hormones in women, mercury accumulates in the hypothalamus and pituitary. Both of these hormone-producing glands are responsible for the proper functioning of the female hormones. Fertility is based on the functional integration of the hypothalamus, pituitary, ovaries, and uterus. The hypothalamus produces Gonatatrophin Releasing Hormone which tells the pituitary to release the Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). Studies on women who work around mercury show menstrual cycle disturbances, hypomenorrhea, or hypermenorrhea.
Some studies suggest endometriosis is linked to abnormal immune function. Mercury weakens the immune system. One of the ways it does this is by depleting the adrenal glands of B-5 and ascorbic acid. This causes a decrease in adrenal hormones which then leads to decreased immune function. Add stress, which can also ultimately decrease adrenal function and you have a recipe for problems. Also, mercury interferes with an enzyme called cytochrome P450. This enzyme is important in the production of progesterone, a major female hormone. The list goes on and on.
A study was done in Hong Kong on 150 infertile couples undergoing in-vitro fertilization versus 20 fertile couples. The infertile couples had significantly higher blood mercury than the fertile group. Over 1/3 of infertile men had abnormally high mercury and about 1/4 of the infertile females had high mercury levels. Considering they looked only at blood, fish may have been the culprit. Mercury in the blood often will reflect fish intake. Too bad they did not run tests to check on the tissue burden of mercury.
EFFECTS ON CHILDREN
There is also evidence that the mercury in a mother’s fillings is passed along to her unborn child. In a very compelling study in Canada by Drs. Fritz Lorschneider and Murray Vimy, amalgam fillings were placed in the teeth of pregnant sheep. The mercury in the fillings was radioactively labeled so that the scientists could definitively trace the mercury to the fillings. Within days, they found the amalgam-related mercury in all the tissues of both the mother sheep and the unborn fetuses, and especially in higher concentrations in the kidneys, thyroid, intestines, and jaw bone8. A German study conducted in 1994 found that mercury in Sudden Infant Death Syndrome (SIDS) babies’ brains were directly proportional to the number of fillings in the mother’s mouth, providing further compelling evidence that mercury travels to the developing fetus and may be a factor in SIDS9.
Many studies on animals and the effects of prenatal exposure to low-level mercury vapor have been done which show adverse effects on brain function. In one test on an isolated group of humans – residents of the Faroe Islands in the Pacific ocean – scientists tested 112 children whose mothers prenatally had hair mercury levels of 10 to 20 mcg per gm (which is considered normal range) compared with controls whose mothers had hair mercury levels of 1 to 2 mcg per gm. At 7 years of age, the former group showed mild decrements relative to controls in motor function, language, and memory.11
Some of the most ominous findings related to mercury have been autopsy studies showing that the amount of mercury found in the tissues of the brain directly correlates to the number of mercury amalgam fillings in the mouth.1 Keeping this in mind, it may demonstrate a direct link to Alzheimer’s based on studies by Dr. Boyd Haley. Dr. Haley, from the University of Kentucky, has conducted significant research into mercury exposure from amalgams. Dr. Haley discovered that patients with Alzheimer’s disease have higher than average levels of mercury in the tissues of the brain, establishing a correlation between Alzheimers and mercury amalgam fillings. In one study, Dr. Haley and colleagues exposed rats to levels of mercury vapor comparable to what would be found in people with amalgam fillings. The rats then developed changes in the brain similar to the changes which occur in the brains of Alzheimer patients10.
EFFECTS ON BLOOD VALUES
In a study funded by the Coors Foundation, researchers took healthy subjects who had from three to ten amalgams. They had no root canals or other metals in their mouths. Blood testing was done to check, among other things, white blood cell counts – to reflect immune system functioning; oxyhemoglobin levels; cholesterol values; and a whole host of other parameters. They then removed the amalgams, replaced them with composites, and took the second set of blood samples. The removal of the amalgams affected the numbers in a positive direction. The white blood cell counts settle into a narrow corridor of 5-6,000. Venous oxyhemoglobin, which measures the actual percentage of oxygen saturation, increased in twenty out of twenty-seven patients. Low cholesterol values went up and high values came down toward the optimal two hundred and twenty-two. The composites were then removed and the amalgams reinserted. The blood results were affected in a negative manner. A second removal of the amalgams again caused a positive change in blood test results.12
Many dentists are rapidly discovering that their patients are recovering from a broad range of illnesses when their silver amalgam fillings are replaced with less toxic materials. People who were barely functioning have regained all or most of their faculties. Sometimes the recoveries are fairly rapid. There are thousands of anecdotal reports by dentists, allergists and other medical professionals attesting to the link between becoming “mercury free” and a fast, dramatic, and otherwise inexplicable improvement in symptoms.
There are many more cases unreported in which the improvement is being termed spontaneous remission. At this point, many doctors refuse to believe in any link between amalgam fillings and ill health, even when the positive results of removing those fillings are staring them right in the face. The ADA calls the mounting anecdotal evidence insignificant and argues that there is no proof that mercury fillings are unsafe. But many of the recoveries are so immediate, so dramatic, that you would hardly need to be a trained clinician to make the obvious assumption.
One reason may be that it is particularly difficult to pinpoint the symptoms of mercury poisoning. Mercury poisoning is nothing new; in fact, the expression “mad as a hatter” refers to mercury poisoning contracted by hatters, who processed hat felt using mercuric chloride. The hatters would often develop mental illness as a result of their high exposure to mercury. The symptoms associated with low-level mercury poisoning (micromercurialism) range across a very broad spectrum. Some of the effects of low-level exposure are commonly attributed to stress or aging, like inexplicable fatigue, loss of memory or inability to concentrate, moodiness, anxiety, lack of confidence and even severe depression.
A recent study of 34 practicing dentists and 15 dental assistants has shown adverse effects of cumulative low-level mercury exposure. All had very low urinary mercury levels and had “alteration in moods, deficits in motor function, and subtle losses in memory and visuospatial cognitive skills” that were shown to be related to mercury body burden. Most significant was the fact that the subject’s urinary mercury levels are comparable to the general U.S. population, raising questions as to the effects of amalgam.14
This broad range of systemic response to mercury is based on an individual’s threshold and resistance to toxicity. Many people have what is termed a “high threshold” for toxicity. They may have had mercury fillings for years without experiencing any overt problems. Other persons exposed to the exact same levels of mercury may have dramatically different reactions and symptoms. But even people who seemingly have a high tolerance to amalgam need to be aware of the impact mercury and alien electrical impulses have on the human body. Many of the symptoms that are unfortunately considered “normal,” such as headaches, allergies, stomach troubles, sinus problems, and many other discomforts, may be related to the metals in your mouth.
In the case of serious illness, removal of mercury amalgam fillings often clears up a whole host of low-intensity symptoms which literally interfere with an accurate medical diagnosis. Amalgam removal could very well become the single most important step in enabling your physician to help you get well.
As a consumer, you have a right to know the danger to you and your children of having mercury fillings. Last year, more than 100 million silver amalgam fillings containing 50%, or about one gram (1000 milligrams) of mercury per filling were placed in patients’ mouths. If you have these poisonous fillings, then you are inhaling toxic mercury vapor every day.
The following is a summary of the subjective reports of 1569 patients who participated in six different surveys of health effects after having their amalgam fillings removed.15
| Symptoms Reported|
Percentage of Patients
Claiming Substantial Relief
| Allergy||89% |
|Bad Temper ||89% |
| Bloating||88% |
| Blood Pressure Problems||54% |
| Chest Pains||87% |
| Depression||91% |
| Dizzines||88% |
| Fatigue||86% |
|Gastrointestinal Problems ||83%|
| Gum Problems||94% |
|Headaches ||87% |
| Insomnia||78% |
| Irregular Heartbeat||87% |
| Irritability||90% |
| Lack of Concentration||80% |
| Lack of Energy||97% |
| Memory Loss||73% |
| Metallic Taste||95%|
|Multiple Sclerosis ||76% |
| Muscle Tremor||83% |
| Nervousness||83% |
| Numbness||82% |
|Skin Disturbances ||81% |
| Sore Throat||86% |
|Tachycardia ||70% |
| Thyroid Problems||79% |
|Oral Ulcers ||86% |
|Urinary Tract Problems ||76% |
|Vision Problems ||63% |
These are only a few of the numerous studies on mercury exposure from fillings. It is important to keep in mind, that mercury can travel via various routes from the metal fillings into the rest of the body. The vapor from the fillings can travel through the upper nasal cavity directly into the brain, including the region of the hypothalamus which regulates heart rate, respiration, and blood pressure. It can also travel into the lungs where it can then be absorbed by the bloodstream and carried to tissues throughout the body – especially to the kidneys where it accumulates rapidly. Studies now show that even low-level exposure to mercury is not safe. Remember, the effects of mercury exposure are cumulative and can take years and even decades to surface. If you would like to research the scientific evidence further, we believe you will find these websites enlightening: