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What is there to say about mercury toxicity that hasn't been already, many times over? This heavy metal is another super-toxin with no safe body level in humans, yet, some 150 tons of it are being dumped into air by coal-fired power plants, waste incinerators or chlor-alkali plants, each and every year. Much of it falls back to the ground, contaminating lakes and rivers in the form of methyl mercury, one of the most potent poisons ever known to man. It has entered the food chain and contaminated water supply.
While mercury emission from incinerators is, due to new regulations, reduced to a fraction of what it was just a decade ago, the main single source of environmental mercury pollution - power plants - remains untouched. This is despite the initiative from the highest level (U.S. senator Patrick Leahy, Vermont), which only proves that for the decision-makers big economic interests still rate higher than public health concerns.
And, instead of lowering the exposure, we were making it worse. Not too many things are more senseless than putting mercury straight into people's mouths. And that is exactly what has been done by the dental profession to many millions of Americans, implanting into their teeth silver/mercury amalgams. These fillings are about 50% mercury, 25-30% silver, 10-15% tin, a few percents copper and trace of zinc. This alloy is not corrosion-resistant, and begins to release gasses, ions and microscopic particles from the moment it is placed into the mouth. Any of its metal constituents can be toxic, but the primary concern is mercury.
According to the measurements of the Swedish scientist Dr. Jaro Pleva, amalgam mercury content reduces to 27% after five years, and to only 5% after 20 years. That implies the
average mercury content loss of about 15% a year,
with the actual amount of leak highest during the first few years, when most of the mercury is still present in the amalgam.
The average amalgam weights about 1g, and sits in the mouth for about 8 years. According to these figures, during that time it looses about 2/3 of its mercury content, or 0.33g. That comes to 115μg a day as the 8-year average. During the first year, the exposure is as high as 200μg a day, falling to 67μg a day during the last, eight year.
The first year mercury exposure from a single amalgam
exceed almost six times the FAO/WHO
(0.5μg per kg of body weight a day) for a 70kg (156 pounds) person! Even eight years after, exposure from a single amalgam would be nearly double the safe limit.
Of course, Dr. Pleva's measurements do not represent one-for-all rate of mercury leakage. Variations are unavoidable, and possibly significant. But the fact that it can reach such a high level is very alarming.
Portion of this constant toxic leak is swallowed and absorbed into the bloodstream. Mercury ions, another form of amalgam corrosion created by galvanic (battery-like) effect between different metals and mediated by saliva, migrate into surrounding tissues and bones, finally reaching the brain.
The third form of amalgam erosion is mercury vapor - the ultra-toxic methyl mercury. It is either inhaled, finding its way into the bloodstream through the lungs, or absorbed by tissues in the upper oral cavity. How much of mercury vaporizes from amalgams is greatly influenced by chewing - specifically, by the chemistry between amalgams and saliva taking place inside the mouth (which can also be significantly affected by the presence of metals other than amalgams themselves).
For instance, measured level of mercury from fillings in respired air went from 2.8μg/m3 (corresponds to about 0.02μg per minute) to 40μg/m3 before and after chewing gum, respectively4. For comparison, the current OSHA (Occupational Safety and Health Administration) standard for mercury is 100μg/m3 averaged over an eight hour work shift, with the National Institute for Occupational Safety and Health recommending half as much for 40-hour work week. Since a person with amalgams is exposed for more than 4 times longer hours, the corresponding limit for mercury vapor released from amalgams would be 12μg/m3.
This is, of course, still only a number; no one can guarantee that this level of constant exposure is safe, especially for children and during fetal development, simply because
no long-term study
establishing such level
And, mercury vapor is only one of three different forms of mercury from amalgams contaminating the body.
Mercury released by amalgams reaches the brain either via bloodstream, or by migration through surrounding tissues. Once there, it damages brain enzymes and pituitary gland - the master gland, affecting the function of all other glands. But it also spreads through and poisons rest of the body.
In a Canadian study, radioactive mercury-silver fillings were placed in the teeth of adult sheep; within 29 days, mercury from the fillings was found in jaws, gastrointestinal tract, blood, liver, kidneys, adrenals, thyroid, cerebrospinal fluid, pituitary gland, thalamus, frontal and occipital cortex of the animals (Hahn et al, 1989).
It is not in question whether mercury from dental amalgams spreads throughout the body. The only question is what specific effects that will cause. With its ability of binding to and altering protein molecules, thus inhibiting enzymes, damaging immunoglobulins and interfering with basic cellular functions,
mercury will inflict damage wherever the body is vulnerable.
Since vulnerabilities and state of health vary individually to a great extent, so do the symptoms of mercury poisoning.
According to the data from 1,569 patients who removed mercury-silver fillings, among the most frequent immediate and short-term symptoms of mercury poisoning are fatigue (45%), headaches (35%), depression (22%), dizziness (22%), lack of concentration (17%), memory loss (17%), metallic taste (17%), intestinal problems (15%), allergy (14%), insomnia (12%) and irregular heartbeat (10%). After amalgam removal, 73-95% of these symptoms either vanished or subsided (Alternative Medicine, Goldberg, p87).
One possible common effect of mercury toxicity, experienced by the man who beat Alzheimer's (Tom Warren, Beating Alzheimer's), is shutting down production of stomach acid. This in turn causes incomplete digestion and absorption, resulting in severe nutritional deficiencies, intestinal inflammation, leaky gut, immunosuppression (remember, up to 2/3 of the immune system is tied to the intestinal tract) and immune malfunction, leading to a development of crippling sensitivities and allergies.
Removing amalgams does not necessarily solve all, or even the worst problems. One of the two main reasons are that mercury often has been accumulating in the body for years, and requires more time to clear from the body enough to ease the symptoms - especially mercury accumulated in the brain. The other reason is that amalgam removal may not be done properly, resulting in possibly
even more extensive body contamination
(proper amalgam removal procedure id described by the author of the pioneering book on amalgam toxicity - It's all in your head - Colorado dentist Dr. Hal Huggins).
Part of the proper procedure is test whether alternative filling material is biocompatible with the patient; if not, it will also have toxic effect.
Needless to say, longer term accumulation of mercury is very likely to cause, or contribute to some form of chronic disease. Among them are sensitivities, allergies, immunosuppression, auto-immune diseases like multiple sclerosis, or Lou Gehrig's disease, compromised neural function (brain damage), cardiovascular diseases, kidney disease, depression, schizophrenia, chronic fatigue, fibromyalgia, unexplained body pains and aches, and so on.
While biological half-life (period of time in which the body disposes of half the substance it absorbs) for mercury is only 74 days,
its removal from the nervous system occurs at much slower rate,
which is why this body function suffers the most. Mercury and its metabolites are fat-soluble toxins, with high affinity for fatty tissues, and the brain has the highest fat concentration of all organs.
Mercury/silver fillings are the main source of mercury contamination for the general public. Experimental data (Radics et al, 1970) indicates that the probable average amount of mercury leaching out of a single dental filling reaches 15μg/day. The World Health Organization came up with 3-17μg/day, or about 10μg/day average. That is substantially less than what is indicated by Dr. Pleva's measurements (and suspiciously juuust below the WHO's official safe exposure limit).
Mercury also finds its way into the body through consumption of mercury-contaminated foods. Here's how orally consumed methyl mercury affects the body4:
it binds to plasma proteins and hemoglobin
in red blood cells, then
Main food source of mercury contamination is fish, in particular large predatory fish with relatively long lifespan, like shark and swordfish. They often contain between 1ppm (parts per million, or micrograms per gram) and 2ppm of mercury. Big tuna (bigeye, albacore, blue fin) mercury content is approximately 0.3ppm to 0.6ppm, while smaller tuna ("light") averages below 0.2ppm. Shrimp averages 0.05ppm of mercury (Canada Health).
While the benchmark for "safe" mercury intake for adults is officially 0.5 μg/kg (microgram/kg) of body weight a day (FAO/WHO) - and 1/5 as much for pregnant women and children - these are no more than general estimates, and not to be considered safe individual thresholds. Scientific study on the long term health effects of mercury is yet to be conducted.
Considering a number of factors - from the lack of scientific basis for the current official "safe" exposure limit for mercury, to great individual variations in vulnerabilities, and to the likelihood of many times magnified adverse health effect of any single toxin when combined with other toxins in the body, a
really safe upper intake of mercury should be much lower,
preferably zero for children.
From the above numbers, a 70kg (155 pound) person, shouldn't be consuming more than 600g of tuna weekly. This is assuming no other mercury intake. However, with mercury coming uncontrollably from other sources (industrial and auto exhaust, electrical equipment, silver amalgams, paint, paper, cosmetics, pharmaceutical products, preparation H for hemorrhoids, common injectable-medications preservative, organomercurial fungicides contaminating grain, drinking water supply, etc.), you might be better off with no tuna at all.
If you have, say, only two dental amalgams in your mouth, that alone fills out your quota for officially "safe" mercury exposure.
Especially worrisome is mercury exposure of the newborn through vaccination. By the age of 2, an average American child was, up until a few years ago, injected by 237μg of mercury (in the form of vaccine preservative thimerosal), which is roughly half of the official safe level for that period (based on 0.1μg/kg/day official safe limit). By the time they were six months old, according to the FDA findings, regularly vaccinated children have been injected with up to 187.5μg of ethyl-mercury. That is roughly double the official "safe" limit from vaccinations alone.
The problem is not only the arbitrary nature of the limit, and the certainty of additional mercury contamination of unknown magnitude from other sources, but also that the official limit is for ingested methyl-mercury. Thimerosal is, on the other hand, ethyl-mercury based, and there is no federal guidelines - even arbitrary - for its toxicity. Preliminary 2005 study (Burbacher) has found strong indications that ethyl-mercury is significantly more toxic than methyl-mercury, and has concluded that further investigation is "urgently needed".
Therefore, it is quite possible that many American child was injected with the equivalent of up to
several times the officially safe limit of mercury
Assuming, of course, that the present official "safe limit" for mercury is really safe, which is highly questionable considering both, wide variations in individual vulnerabilities and simultaneous exposure to so many different toxins.
Mercury from thimerosal has particular affinity for the nerve cells. One possible consequence with small children is autism, whose epidemic nearly coincides with the era of huge expansion in early childhood vaccinations, beginning back in the early 1970s (Evidence of Harm, Mercury in Vaccines and the Autism Epidemic, by David Kirby). After a few short years since the 1999 government's request to minimize or eliminate the use of thimerosal in pediatric vaccines as expeditiously as possible, the evidence of
downward trend for neurological disorders in children
has been published in the Journal of American Physicians and Surgeons (and, expectedly, denied by the US Centers for Disease Control, which played a major role in making thimerosal-containing vaccines mandatory).
There are other mechanisms besides mercury toxicity, through which very early vaccination can cause this and other adverse health effects in very small children, which is why it is practiced to much lesser degree in most of Europe.
At present, thimerosal shouldn't be present in significant amounts in most newly produced pediatric vaccines in the U.S. Still, due to regulatory issues (and, evidently, lack of decisive action on the side of the government), some of them - mostly flu shots - will contain up to 25μg of ethyl-mercury till 2008. Also, use of old-stock mercury-contaminated pediatric vaccines is allowed, with good portion of them being "generously" dumped as aid to "third world" countries.
There was no significant reduction of thimerosal content in vaccines for adolescents and adults.