| Betreff: Mercury in Fish |
| Von: ECOTERRA Intl. |
| Datum: Wed, 07 Sep 2005 09:24:37 +0300 |
Mercury in Fish
Mercury
in all of its forms is toxic to the fetus and children and
efforts should be made to reduce exposure to the extent possible to
pregnant women and children as well as the
general population[i].
In
recent years, several agencies of the
We are led to believe that these agencies are trying their best to be sensitive to the effects of chronic low level toxicities especially on pregnant women and the newborn that are most vulnerable. There is much conflict in the medical and scientific world about what constitutes a low level of toxicity and what effects might be expected. The few major studies being used are in conflict and thus officially no one really knows the exact danger. Thus it is not clear how much fish is safe to eat or how many dental amalgams in an expectant mother will lead to enough toxicity to damage the developing fetus.
What is clear
is that
mercury concentration levels are rising, clearly it has been
demonstrated that through eating fish, leakage of dental amalgam, and
injection of mercury bearing vaccines during pregnancy or at birth,
mothers and children are being exposed to higher levels of mercury than
ever before. Unfortunately government guidelines do not allow for
individual differences or hypersensitivity to the effects of this or
any poison. They also do not differentiate for different modes of entry
into the body, i.e., through injection, digestion or absorption through
the lungs. There are many molecular forms of mercury each with its own
toxicity level, some vastly more toxic than others. When it comes to
mercury the molecular form is crucial as is the mode of ingestion as is
a person’s individual nutritional profile which determines their
ability to excrete the mercury or cancel out its poisonous effects.
Selenium levels, for instance, are crucial, as are glutathione levels.
Both are potent antidotes for mercury and their scarcity in the body
only increases mercury’s toxicity.
Complicating
mercury toxicity are other chemicals
like lead and aluminum that increase
mercury
toxicity
and other chemicals like selenium that reduce it.
Though
scientists do not know the actual toxicity of mercury in fish, federal
and state agencies have decided, quite appropriately, to be cautious
especially in regards to pregnant women, even though the Seychelles study[ii] shows that blood levels of 100 to 200
micrograms of mercury per liter in pregnant women were not associated
with detectable abnormalities in the children exposed in utero. A good
reason for caution is other extensive studies of mercury impacts on fetal
development have shown mercury to have deleterious effects. The
Hence it may be
that had the
The FDA advises vulnerable groups to eat “only” two fish meals (up to 12 ounces) per week of fish with “lower levels” of mercury so as to avoid the accumulative effect of the toxic substance. That recommendation has mothers eating about 40 mcg per week of methyl mercury which would be roughly the equivalent of two thimerosal bearing flu vaccines per week. There are no shortages of doctors who would say that such a vaccine schedule, especially for a young pregnant woman would be suicide so it seems that the mercury from fish is considerably less toxic than from vaccines.
The big question mark and variable is perhaps not just the toxicity, molecular form or mode of ingestion but the sheer quantity of mercury the body has to handle. That is why doctors in the future have to become mercury experts. They need to count how many fillings are in a patients mouth as well how much fish is being eaten and to factor in other variables like increasing air and water mercury pollution and other variables like lead concentrations (makes the mercury much more toxic) and even arsenic poisoning. Arsenic is a key not only for its own toxicity but because it sequesters selenium supplies from the body.
Selenium
is the primary antidote to
mercury poisoning, our first line of defense.
Commercial
interests like the US Tuna Foundation would have us err on the side of
risking pregnant women and the next generation of children saying, “In
reality, no government study has ever found unsafe levels of mercury in
women or children who eat canned tuna.”[vi] They are half
correct in that what the government is showing is mercury in the blood
and in placentas. Mercury levels normally measured are from many
sources and no one has been able to separate out what amount is
specifically contributed by tuna. A study of a Peruvian fish-eating
population, also released by the
More recent
research by Dr. Boyd
Haley the
What society and pregnant women need to be worried about is not
just mercury in fish but total body burden of mercury that
includes dental amalgam and mercury vaccines. It is difficult
to believe that the
Although
The situation is truly difficult. ‘Almost’ everyone agrees that mercury is a potent neurotoxin but each major organization or government has justified rationalizations for making exceptions and special exemptions for mercury’s entrance into the human system through one form or another. Actual mercury toxicity is the total of converging inflows of different forms of mercury coming into the human body in different ways. Is anyone looking at how these different forms reinforce each other to create neurological destruction in the young?
Unfortunately no
and this is
leading scientists and health officials to erroneous and incomplete
conclusions. Mercury is flowing in through peoples’ lungs. It’s
increasing in the air we breathe and all people with dental amalgam are
breathing it in 24 hours a day in large doses. It’s in the saliva and
is swallowed. It’s being eaten in the form of fish and other food
sources. And it’s being injected. It is even increasing in the water we
drink. Though the forms of mercury are different each form and source
is adding to total body burden and total accumulated toxicity.
It is important to know that mercury appears in a
variety of
forms and that a whole range of toxicity exists depending on the
molecular identity of each form. Pharmacist Richard Harkness
recently published an essay titled: Flu vaccine mercury poses little
health risk.[xii] He says “One way to gain perspective is to
compare the amount of mercury in the flu shot with the amount found
naturally in tuna fish.” He lets us know that there are, on average,
0.12 micrograms (mcg) of mercury per gram in tuna[xiii] so a typical 6-ounce (170 grams) can of light
tuna would thus contain approximately 20.4 mcg of mercury. That's very
close to the 25 mcg of mercury contained in the adult dose of the flu
shot.
Harkness
then goes on to say that “the form of mercury in flu vaccine (ethyl
mercury) is deemed less likely to cause harm than that present in
seafood (methyl mercury),” and thus concludes that, “The bottom line:
For most people, the risks and miseries of getting the flu far outweigh
any risks that might be associated with mercury in the flu vaccine.”[xiv] Certainly in saying this he has not heard Dr.
Mark Geier and David Geier, who are on the cutting edge of research in
the role of mercury in vaccines. They
found
that children who received the DPT course of vaccines that contained
mercury had a 2700% higher incidence of rate of autism than children
who did not get mercury. In reality the distinction between ethyl and
methyl mercury, for those knowledgeable about mercury toxicity, comes
down to the difference between one deadly snake venom and another. A
serious problem with the above comparison is the assumption it makes
that the mercury in fish is in fact methyl mercury.
Dr. Boyd
Haley, speaking to the State Assembly in
Very few people are aware of a Canadian researcher who, using a technique called x-ray absorption spectroscopy, found that a great deal of the mercury stored in fish tissues is in a different form than methyl mercury. Rather than bound to hydrogen and carbon atoms, it has formed tight bonds with sulphur atoms, which, in principle, should make it far harder for the mercury to be taken up by the human body. Dr. Graham George found that fish do not contain methyl mercury chloride, but methyl mercury cysteine. This means that it would be potentially less toxic than methyl mercury.
Dr Graham George, who
carried out the study
while based at
There
are several mechanisms at work in determining the toxic problem from
each mercury source and their combined intake. The mystery
of mercury toxicity is tied very closely to our ability to eliminate
mercury through the feces, urine and skin and mechanisms in both fish
and people that render the mercury into a stable non-toxic form. To give us some perspective on this we can look
at mercury exposure and elimination rates in captive
bottlenose
dolphins. Results showed that feces account for elimination of
34-48% of dietary mercury; while only 0.9-1.2% of alimentary mercury is
eliminated through exhaled air. The remaining 51.2-65.3% of ingested
mercury, ranging approximately between 266 and 339 micrograms per day,
is retained within the organism. The complexation of mercury with
selenium, forming insoluble tiemannite granules was seen to be an
important mechanism, complementary to excretion, by which dolphins are
able to cope with elevated alimentary exposure to mercury.[xv]
Selenium
is certainly one defensive measure operative in humans as it seems
cysteine is another and both combine as essential precursors in
glutathione production. Ocean fish have obviously developed their own
defensive mechanism through the ages due to existent natural sources of
mercury. It is not known whether fresh water fish would share this in
common with their salt water brethren but it does seem that dolphins
and whales are having their defensive mechanisms stretched to the limit
like humans are through the profoundly increasing mercury levels in
certain areas.
What is not known is how much the
protective
mercury mechanisms in fish do to protect humans from the toxicity of
mercury when they eat fish contaminated with mercury. The form of
methyl mercury cysteine offers possible reason why an adult eating a
juicy shark steak could ingest several hundred micrograms of organic
mercury and not create the same problem as injected mercury or mercury
absorbed through the lungs because of badly leaking dental amalgam. It
does seem that eating mercury in the form of fish might be less toxic
than other forms but even at a highly reduced toxicity it seems to be
flooding the blood with mercury because of the sheer volume eaten from
a regular diet of mercury contaminated fish.
In
an ideal world where we can eat all the fish we would like we would
have to think of this methyl mercury cysteine form as being completely
inert. An inert chemical substance is one that is not reactive. But
nothing will erase the fact that dietary mercury increases mercury
concentration in the blood. In one study EPA scientist Dr.
Katherine Mahaffey found mercury blood concentration levels were seven
times higher among women who reported eating nine or more fish
and/or shellfish in the past 30 days.[xvi]
Some scientists are calling mercury "the new lead." As with lead, the more scientists study mercury, the more they find subtle damage to the brain at lower and lower levels of exposure. Dr. Boyd Haley declines to state a specific toxic level for each form of mercury because patients differ so widely in their ability to detoxify and excrete mercury and lead is only one of many confounding factors that dramatically increases the toxicity of mercury. It is really impossible to create standards for exposure since people’s sensitivities and situation vary so greatly.
Smoking cigarettes, which
injects over 4000
chemicals into the blood, antibiotics, aluminum and formaldehyde found
in vaccines, even one’s sex is a great factor in mercury toxicity. Many
more boys succumb to autism than girls because of the hormone
testosterone. The presence of selenium or its absence is a key issue as
is diet in general. A diet high in cysteine and selenium could easily
explain why a selected population would show no immediate harmful
effects from mercury even in a lowered toxic form that methyl mercury
cysteine might represent. We even find alcohol consumption (ethanol)
reducing mercury toxicity so those who drink while they eat fish would
be more protected than those who abstain.[xvii]
Dr. Jay
Murray, a
toxicologist that specializes in maternal and fetal health and a member
of the Tuna Nutrition Council, says "We now have proof that mercury
levels in the vast majority of women and young children in the
Dr.
Fletcher in
In
2003 the California Attorney General's office felt that not enough was
being done to inform the public of the dangers so it filed suit to
force supermarkets, restaurants and tuna companies to warn customers
that tuna (fresh, frozen and canned), swordfish and shark sold in their
markets contain mercury.[xix] The suit was based on the state's Proposition
65 which requires consumer warnings for substances on a toxics list. In
January 2005, 16 major restaurant chains sued by the state agreed to
settle and put up warnings. The US Tuna Foundation challenged the
lawsuit saying "canned tuna products are safe…." In February warning
signs were beginning to be posted.
According
to the New York Times when “the FDA issued a revised mercury advisory
in 2001, it urged women of childbearing age to shun four high-mercury
species: swordfish, shark, king mackerel and tilefish from the
FDA
scientists have put fish in three categories: high in mercury, medium
and low. The level for the low-mercury group was that of canned light
tuna, explained FDA official Clark Carrington, who according to the New
York Times and official transcripts of a meeting between the EPA and
the FDA said, "In order to keep the market share at a reasonable level,
we felt like we had to keep light tuna in the low-mercury group." At
the meeting this point was reiterated by the FDA's Dr. Acheson who told
the meeting the fish categories "were arbitrarily chosen to put light
tuna in the low category." Of this Dr. Rice said, "Here's the FDA
making what are supposed to be scientific decisions on the basis of
market share. What else is there to say?"
In February of 2005 Jyrki Virtanen with
the
Research Institute of Public Health at the
The
study found a 50 percent to 70 percent greater risk of heart attacks,
heart disease and cardiovascular disease in men ages 42 to 60 that had
elevated levels of mercury in their bodies. The
study, which is following the health of 2,682 Finnish men, found that a
third of study participants who tested highest for mercury also
reported eating an average of twice as much fish as the rest of the men
in the study. "In terms of the type of evidence we often use to
evaluate health risks from toxics, this is a pretty good basis for
concluding a likelihood of a relationship between mercury and
cardiovascular disease," said Alan Stern, a toxicologist who was a
member of a landmark National Academy of Sciences committee that
evaluated the health risks of mercury in 2000. Mercury has also been
determined to have the best predictive value for intimal wall thickness
and was associated with progression of carotid atherosclerosis.[xxiv]
Guallar et al. report that a
toenail mercury level as low as 0.11 to 0.66 µg
per gram (estimated hair level, 0.34 to 2.03 µg per
gram)
was directly
associated with a doubling of the risk of myocardial infarction.
The most troubling aspect of
Virtanen’s study is
that deleterious effects occur at mercury-exposure levels equal to or
lower than for any other toxicological outcome, including the subtle
neurological symptoms in the
Dr.
Laurie
Green of the Pacific Women’s Obstetrics and Gynecology Medical Group
now asks her patients to record not only what fish they eat but how
much. “I’ve been astounded at how many patients have high mercury
levels and underestimate their fish intake,” she writes. Dr. Green was
amazed to discover “how much better they feel once they cut out the
contaminated food.” Of course the same thing is reported by many
patients who have their mercury fillings removed and parents who have
spared their children from all mercury bearing vaccines report children
of fine health. Dr. Jane Hightower is another physician who noticed, in
her
What conclusion can we draw from all the above? It will be years before we completely sort out the different pathways mercury takes in building toxic body burdens. It is ‘somewhat’ dangerous to eat fish very high in mercury content, especially if one already has low selenium levels because of poor diet and high mercury burdens present from vaccines and dental amalgam. Certainly we do not want to be eating shark, dolphin or whale livers. It is relatively easy to take the mercury out of vaccines because there are other safe alternatives to thimerosal, but this is not being done in most of the world. Mercury dental fillings can now easily be avoided because there are excellent alternatives but this is not embraced by the American Dental Association and the dental branch of the FDA.
Fish
is another story.
It is a main dietary source of protein and one that many people feel,
in moderation, is excellent for ones health. For many peoples around
the world it is not a luxury but a dietary staple and there is
little or no affordable alternative. It ‘might’ be safe to conclude (in
a world where there is no rising tide of mercury, where vaccines and
other medical products are mercury free, where dentists abandon placing
toxic mercury waste dumps in peoples’ mouths, where its not increasing
in the water and other food supplies) that mercury in ocean fish would
pose little threat to the general population. But not matter what
it
seem prudent that all pregnant and breast feeding women should be
well
advised to stay away from fish for there is no doubt that it will raise
blood mercury levels and that their placentas will concentrate that
mercury by a factor of 1.7. No matter what it would be intelligent to
make sure one’s selenium intake is more than adequate for protection
from absorbed mercury’s harmful effects if one were to continue to eat
fish.
The
following case story on mercury poisoning from eating tuna fish
appeared on the front page of the The Wall Street Journal on
One by
one, Matthew Davis's fifth-grade teachers went around the table
describing the 10-year-old boy. He wasn't focused in class and often
missed assignments, they said. He labored at basic addition. He could
barely write a simple sentence.
"Our jaws dropped,"
says his mother, Joan Elan Davis, describing a teachers' meeting she
had requested in late 2003, when her son abruptly lost interest in
homework. Matthew had always excelled in school. In the fourth grade,
he had written and illustrated a series of stories about a superhero
named
Ms.
Davis noticed something else: Her son's fingers were starting to curl,
as if he were gripping a melon. And he could no longer catch a football.
A
neurologist ordered tests. They showed Matthew's blood was laced with
mercury in amounts nearly double what the Environmental Protection
Agency says is the safe level for exposure to the metal. Matthew had
mercury poisoning, his doctors said.
The
It
struck Matthew that something was wrong one day at recess, he says,
when his buddy Zach could suddenly catch and throw a football much
better than he could. He remembers his father, a little while later,
getting frustrated when his son couldn't hit a baseball. "I kept
telling Dad I was rusty," Matthew says.
After the meeting
with his teachers, the
Then
Matthew's father happened to read an article in the San Francisco
Chronicle describing adults with similar problems as a possible result
of eating too much swordfish, tuna steaks and other high-end fish in
restaurants. Ms. Davis remembers bolting to the pantry and throwing
away eight pouches and 20 cans of StarKist albacore tuna.
Matthew Davis's symptoms -- declines in
concentration, coordination and learning ability -- were classic signs
of mercury toxicity, says one of his doctors, Jane Hightower, who has
published studies of such toxicity in her patients. Today, nearly two
years after Matthew quit eating albacore tuna, his blood-mercury level
is zero and his condition is dramatically improved. Although his
doctors don't know if he had any permanent damage, signs so far are
that he didn't. Sports and homework come much easier again. Matthew
played the lead in a local performance of "Charlie and the Chocolate
Factory." He is writing stories again.
[i] Goldman, Lynn R. Shannon, Michael W. The Committee on
Environmental Health, Pediatrics, Volume 108, Number 1, July 2001, pp
197-205
[ii] Myers, GJ, PW Davidson, C Cox, CF
Shamlaye, D Palumbo, E Cernichiari, J Sloane-Reeves, GE Wilding, J
Kost, L-S Huang, and TW Clarkson. 2003. Prenatal methylmercury exposure
from ocean fish consumption in the
[iii] Faroes study: Neurotoxic Risk Caused
by Stable and Variable Exposure to Methylmercury from Seafood (Faeroes
study), P. Grandjean et al, Ambulatory Pediatrics, Jan-Feb. 2003.
[iv] Our Stolen Future.
http://www.ourstolenfuture.org/NewScience/oncompounds/mercury/2003/2003-0515myersetal.htm
[v] Hightower, Jane. Mercury and Human
Health: A case study in Science and Politics
[vi] US Tuna Foundation. Understanding
Mercury Levels in Canned Tuna. 2005
http://www.tunafacts.com/mercury/myths.cfm
[vii] Hightower, Jane. Mercury and Human
Health: A case study in Science and Politics
[viii] Rickey T. COMMERCIAL FISH: EAT UP,
DESPITE LOW LEVELS OF MERCURY.
[ix] Holmes, A.,
Blaxill, M., and Haley, B. Reduced Levels of Mercury in First Baby
Haircuts of Autistic Children. 2002 submitted International J.
Toxicology.
[x] Testimony Before the House
Government Reform Committee by Boyd Haley, Ph.D.
[xi] Goldman, Lynn R. Shannon, Michael W.
The Committee on Environmental Health, Pediatrics, Volume 108, Number
1, July 2001, pp 197-205
[xiii]
According to the EPA, light tuna, considered to be low in mercury,
contains an average of .12 parts per million of mercury. www.cfsan.fda.gov/~frf/sea-mehg.html A solution with a concentration
of 1 ppm has 1 gram of substance for every million grams of solution. 1
ppm equals 1 mg of substance per kg of solid (mg/kg).
[xiv] Comparisons between
the different modes of mercury exposure are indeed useful for each form
of exposure highlights interesting information about the other. The
above analogy assumes a level playing field of mercury toxicity between
one form of mercury and another and one form of entry into the body and
another. It also assumes that the form mercury takes in fish is indeed
methyl mercury. In investigating a subject as serious as mercury
toxicity and its effect on children it behooves us to pay attention to
the details and to see the serious flaws in what people say. Since day
old infants do not eat 6 ounces of tuna we have to translate Harkness’s
comparison to make it a fair one. He is correct in that an adult would
receive 25 mcg of thimerosal in a flu shot and that six ounces of tuna
would be safe for a 200 pound man. In many parts of the world today
though, (and between 1991 and 2002 in the United States), newborn
babies receive the Hep B vaccine and this does approximate the 20 to
sometimes 30 micrograms of organic mercury in an average can of tuna. Since the average infant weighs about 7
pounds, the
weight equivalent number of cans of tuna for an adult transposed down
to the weight of an infant would be 28 cans for the infant. That would
boil down to approximately 840 micrograms of mercury. That is a lot of
mercury and newborn babies who have no gallbladder bile capacity to
excrete it.
[xv] Nigro M, Campana A, Lanzillotta E,
Ferrara R. Mercury exposure and elimination rates in captive bottlenose
dolphins was studied in Italy Dipartimento di Morfologia Umana e Biologia Applicata,
sez. Biologia e Genetica, Universita di Pisa, Via Volta, 4 I-56126
[xvi] Mahaffey KR, Clickner RP, Bodurow
CC. Blood organic mercury and dietary mercury intake: National Health
and Nutrition Examination Survey, 1999 and 2000. Environ Health Perspect. 2004
Apr;112(5):562-70.
[xvii]
[xviii] The
[xx] New York Times
[xxi] Salonen JT, Seppdnen K, Nyyssvnen K,
Korpela H, Kauhanen J, Kantola M et al. Intake of mercury from fish,
lipid peroxidation and the risk of myocardial infarction and coronary,
cardiovascular, and any death in Eastern Finnish men. Circulation
1995;91(3):645-655.
[xxii] Guallar E, Sanz-Gallardo I et al. Mercury,
fish oils, and the risk of myocardial infarction. NEJM
2002;347(22):1747-54.
[xxiii] Rissanen T, Voutilainen S, Nyyssvnen K, Lakka TA,
Salonen JT. Fish oil-derived fatty acids, docosahexaenoic acid and
docosapentanoic acid and the risk of acute coronary events. Circulation
2000;102:2677-2679.