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Mercury, lead, arsenic, and other metals have been known to be potential toxins
for many centuries. When body levels become elevated to a point higher than a
safe threshold for tolerance, mercury, lead, and other metals can lead to
illnesses and can exacerbate existing diseases. Unfortunately, symptoms of heavy
metal toxicity are relatively non-specific and non-diagnostic. There are many
other diseases that can easily be misdiagnosed as metal toxicity. A long list of
potentially toxic symptoms can cause a person with just about any chronic
illness to believe that they are poisoned.
Every metal known to science is widely present in the earth's crust, in air, in
water, in food and in drink—often in very tiny amounts. It is important to
understand that all known toxins have a safe low level below which no harm
occurs. Below a threshold of safe tolerance, potentially toxic metals will cause
no harm.
Laboratory technology has now advanced to the point where extremely low levels
can be measured in virtually every person tested. This is increasingly causing
fear and a mistaken diagnosis of heavy metal poisoning. It has become
fashionable to blame a wide variety of poorly understood diseases on heavy metal
toxicity, even when measured levels are much lower than the safe threshold. Some
laboratories print test results on report forms that seem to significantly
exaggerate toxicity. By using a provocative chelating agent before collecting
urine for testing, deceptively elevated levels can be measured in urine. I no
longer recommend provocative urine tests and rely on
whole blood testing,
performed by either LabCorp or Quest Diagnostics laboratories. Those two
laboratories are available in just about every city in the USA and they print
their results on report forms that use scientifically approved EPA and OSHA
reference ranges.
Toxicity does occur and should not be ignored, but when tested properly, using
scientifically accepted standards, toxicity not common. It is true that mercury
levels are somewhat higher in people with mercury amalgam fillings in their
teeth, but recent research shows that levels still remain low enough to be safe.
Please don't misunderstand me. I dislike all environmental toxins. I
enthusiastically support efforts to reduce exposures and to eliminate industrial
pollution. It also makes good sense to use nontoxic substances in dental
fillings. But it makes no sense to miss a correct medical diagnosis by
mistakenly attributing symptoms to low levels of potentially toxic heavy metals.
Many patients have come to me over the years after being told elsewhere that
mercury or some other metal was causing their symptoms. After being tested
properly, using the latest methods and technology, I rarely confirmed heavy
metal toxicity. I have tested many hundreds of patients over the years and found
that only a small percentage that had significantly high levels of toxic metals.
Two recent studies performed by the University of Washington show that mercury
in amalgam dental fillings did not result in high enough mercury levels to cause
health problems, even in young children
Bellinger DC, Trachtenberg F, Barregard L, Tavares M, Cernichiari E, Daniel D,
McKinlay S. Neuropsychological and renal effects of dental amalgam in children:
a randomized clinical trial.JAMA. 2006 Apr 19;295(15):1775-83.
DeRouen TA, Martin MD, Leroux BG, Townes BD, Woods JS, Leitao J, Castro-Caldas
A, Luis H, Bernardo M, Rosenbaum G, Martins IP. Neurobehavioral effects of
dental amalgam in children: a randomized clinical trial. JAMA. 2006 Apr
19;295(15):1784-92
The human body continuously eliminates mercury and other toxins in urine, feces,
hair, sweat, nails and skin. If excessive exposure is avoided, the body will
efficiently eliminate most toxins. Mercury, for example, has a half-life in the
body of only two to three months with no treatment at all. DMSA by mouth is the
preferred treatment for excessively high levels, although avoidance of
undesirable exposure is the most important aspect of any treatment plan. DMSA
also speeds the elimination of lead, and arsenic, antimony, bismuth, and gold.
Lead is preferentially stored in bones and for that reason elimination is
slower.
Readers may question what I have written here. I can only refer them to a
large
body of scientific literature on this subject.
A review article in the American Academy of Pediatrics is somewhat more alarmist
with the following conclusions.
MERCURY EXPOSURE
Toxic mercury exposure can occur from industrial effluents, environmental
contamination, occupational exposure, volcanic gasses, and from emissions by
coal fired power plants. Metallic mercury is relatively non toxic and is not
significantly absorbed, even when swallowed by mouth. Metallic mercury does
evaporate, however, and prolonged breathing of the fumes in a closed space can
lead to toxicity.
Lead exposure has greatly diminished in recent years, since the switch to
unleaded gasoline, and lead based paints have been taken off the market.
Potentially toxic metals have always existed in the earth's crust and also in
every human body at safely tolerated levels. We have good scientific data on
which to base the upper safe limits before metal toxicity occurs.
A recent study by the University of Rochester shows that eating ocean fish an
average of 12 meals per week did not cause toxicity from mercury, even in
pregnant women and small children.
By carefully studying large populations of people known to have been poisoned in
epidemics mercury exposure, it has been possible to determine the blood, urine
and hair levels that resulted in toxic symptoms. This was done at Minamata Bay
in Kyushu, Japan. Mercury was there was disposed of into the the bay by a
chemical manufacturing company, Chisso, that used mercury as a catalyst in the
production of acetylaldehyde. Victims were poisoned by contaminated fish and
shellfish from the bay. Another mercury epidemic occured in Iraq, caused by
bread made with wheat that had been treated with a methyl mercury fungicide.
A study was done in the Faro Islands on a population of people who accumulated
mercury by eating large amounts of whale meat. Whale meat contains a a
significant concentration of PCBs, that confused the picture, and whale eating
was in binges when whales were caught. A more recent study in the Seychelles
Islands involved mercury accumulation from ocean fish that were not contaminated
with PCBs and were consumed on a regular basis 12 or more times every week. Data
from these studies indicates that the danger is less than previously feared.
HOW MUCH MERCURY IS TOO MUCH? QUESTIONS AND ANSWERS FROM THE UNIVERSITY OF
ROCHESTER
How is mercury exposure measured? Scientists can determine a person's exposure
to mercury (especially methyl mercury, the most toxic form) by measuring mercury
content in hair. By comparing these levels to the results of very sophisticated
batteries of tests, scientists try to determine the lowest level that might be
harmful.
At what level does mercury become harmful? Based on scientific results from
exhaustive studies of known episodes of poisoning, the World Health Organization
has placed the level at which risk begins at 50 ppm of mercury in hair for most
people. The WHO then applied a safety factor of 10, estimating that a level of 5
or less is safe for even the most vulnerable populations. More recently the
University of Rochester conducted an extensive study in the Seychelles Islands
of the most sensitive population (pregnant women and their young children from
birth onward) where the average hair mercury level is about 7 ppm, about 10
times the level of the U.S. population. These people ate ocean fish 12 or times
or more often every week. Scientists found no harm from mercury at levels up to
15 ppm, nearly twice the average Seychelles level and about 20 times higher than
the average U.S. level. Despite those reports, hair analysis laboratories in the
U.S. continue to report of toxicity at only 1 ppm.
CLINICAL INTERVENTIONS
1) Minimize exposure! Prevention is always better than treatment of symptoms. Be aware of your environment, what you eat and drink, what you apply to your skin and chemicals used in the home or at work. If a mercury thermometer or mercury switch breaks, carefully clean up the metallic mercury residue. Waste disposal facilities usually have a way to dispose of toxic substances.
2) With special laboratory tests, experienced health care professionals can evaluate the mercury load within the body. This can be done by measuring whole blood levels. Urine can also be used and but hair is valid only for mercury. This should be performed by a reputable laboratory, on the order of and under the supervision of a licensed health care professional. When urine is measured, no chelator should be given that could increase provoked excretion and cause false positives.
3) DMSA can be used to remove mercury and is taken by mouth. DMSA binds with mercury, arsenic, lead, and probably with antimony, bismuth, and gold, hastening excretion from the body. The usual adult dose for mercury removal is 500 mg DMSA (five 100 milligram capsules) on an empty stomach on first arising in the morning with a glass of water or juice, and no food for another 30 minutes. This dose is taken 3 days per week with at least one day between each dose. Monday, Wednesday and Friday is a convenient schedule. This is continued for 3 months. Then wait another month without DMSA before retesting mercury levels in the body, allowing mercury to equilibrate with blood and body fluids.
4) EDTA has little or no effect on mercury in the body, probably because mercury binds more tightly to other molecules and is present as organic methyl mercury. Mercury removal is the one problem for which oral treatment is the best choice, using DMSA by mouth.
5)DMPS is potentially too toxic to use and no longer has no place in the practice of medicine.
6) Nutritional supplements, that contain magnesium and selenium, along with a wide variety of other essential micronutrients, can act as partial antidotes to mercury and other metallic toxins.
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Click here for more information about mercury and heavy metal toxicity
RELATED RESEARCH/ARTICLES:
Mercury Fillings: Are they Really Safe?
Clinical Toxicology of Mercury
Treatment of Mercury and Lead Poisonings with DMSA and not DMPS.
Avoid Misleading Provocative Testing
How to Interpret Toxic Metal Blood and Urine Tests.
Mercury Testing is Often Performed Incorrectly, Causing False High Results.
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