Review of: The Toxicology of Mercury — Current Exposures and Clinical Manifestations Thomas W. Clarkson, Ph.D., Laszlo Magos,
M.D., and Gary J. Myers, M.D. NEJM,
By
B. Windham, DAMS Intl Research Director
The Clarkson, Magos, Myers
mercury article in NEJM,
On page 1731 the authors write: "Fish are the main if
not the only source of methyl mercury" and
on
page 1733 that "among humans, the sole source of exposure to methyl
mercury is the consumption of fish and sea mammals."
This is wrong and contrary to published research and
clinical experience. People with no exposure to fish or sea mammals can easily
be found by test to have significant levels of methyl mercury in the blood,
saliva, and brain,. if they have exposure to other
forms of mercury. Dental amalgam is documented to be the largest source of
mercury in most people who have several amalgam fillings; and other forms of
mercury are methylated in the body by bacteria,
yeast, and other methyl donors- making amalgam the largest source of methyl
mercury in many. There is a lot of documentation in
the medical literature :
[ Leistevuo J et al, Dental amalgam fillings and the amount of organic
mercury in human saliva. Caries Res 2001 May-Jun;35(3):163-6; &
****************************
Table 1:
Under mercury vapor they don't point out that dental
amalgam is the largest source of
mercury vapor in most; and that the studies that they show aren't relevant
to this exposure;
There is a huge amount of documentation in the medical
literature regarding the common adverse
health effects from exposure due to dental amalgam that is disregarded by
the authors:
[www.flcv.com/indexa.html]
including over 60,000 clinical cases of recovery from over 30
chronic conditions after amalgam replacement: documentation at: http://www.flcv.com/hgremove.html
The authors don't mention that thimerosal/ethyl mercury are
documented to be a major factor in autism,
ADHD, eczema, etc. or discuss the evidence
- documentation at: www.flcv.com/kidshg.html
Metal-Metabolism and Autism: Defective Functioning of Metallothionein Protein, Amy Holmes, MD; http://www.healing-arts.org/children/metal-metabolism.htm
The authors state that chelation
is not effective for methyl mercury and ethyl mercury poisoning; which is
contrary to evidence and experience:
For ethyl mercury: www.flcv.com/autismc.html
and
extensive other clinical experience and studies from NIH Medline for methyl
mercury
along with: http://www.flcv.com/hgremove.html
(where many of the studies cited
included use of chelation as part of the recovery)
The fact that some people with acute exposures are
irreparably harmed doesn't warrant blanket statements that chelation
isn't effective in general. Thousands are treated with positive results by
doctors throughout the country each year by many variations of what would be
called chelation or detoxification. Since the mercury
forms: vapor, inorganic, organic are being converted back and forth
continuously in the body, one can't neatly split exposure and treatment results
between forms- though there are known differences in general effects and
mechanisms of actions of the different forms.
****************************
page 1732; the authors state wrongly regarding mercury exposure from amalgam
that:
"it was realized that the
actual inhaled dose was small, due to the small volume of the oral cavity"
This statement is strange since they go on to say dental
amalgam is the chief source of exposure to mercury vapor for most. But the fact
that the exposure isn't small but
rather very large and more than
the federal health guideline level is well documented in the medical
literature from the many studies of mercury excretion in those with amalgam(some of which they later quote). Perhaps the problem
is that these researchers do not have experience diagnosing and treating
mercury toxicity and are not aware of what it means to talk of a small exposure
in something so extremely toxic as mercury.
See: www.flcv.com/damspr1.html
And the fact that all sewers and sewer sludge have high(and dangerous levels of mercury) with the largest source being from dental
amalgam(dental offices and excretion of those with amalgam into sewers) is
also disregarded:
www.flcv.com/damspr2f.html
**************************************************************************
There is a typo in the reference they quote on level of
exposure to mercury from amalgam
on
page 1732 (should be 5 rather than 8)
*****************************************************
On page 1733 the authores state:
"Today's occupational exposures, such as in the dental
office are lower and may lead to mild, reversible effect on the kidney or mild
cognitive changes and memory loss"
They site only one fairly old reference that didn't focus
on this issue(though it was a good review), even
though there are hundreds of studies and clinical investigations that document
significant neurological, reproductive, cognitive, and immune effects of dental
office exposures.
[
Mark Richardson, Environmental Health Directorate,Health
There is substantive documentation that those with dental
office exposures have exposures and body
burdens much higher than than the general population
and higher than those patients with amalgam fillings on average, and that in
the long term adverse effects are
common:
*************************************************
On page 1733 they state that "current evidence shows
no connection"for a link between chronic mercury
exposure and chronic neurological or autoimmune conditions such as Alzheimer's,
multiple sclerosis, Parkinson's, etc. In fact there is substantive
documentation in the literature that their statement is not true; they don't
fully review the literature and clinical experience, which is extensive, and
cite only 3 studies which they say agree with their position. The main study
they cite, the nun study, is known to have serious methodological flaws
including no valid control population or measurements of body burden which
caused it to not be published by a scientifically peer reviewed journal.
Another study used serum blood
mercury level to judge body burden, which is well documented to not be
reliable for this purpose. [www.flcv.com/damspr17.html]
None of the studies used reliable measures of body burden,
nor did they bother to measure any of the known susceptibility factors such
as ability to excrete mercury or immune
reactivity, which are documented in the literature to be the major factors
in who is adversely affected my mercury exposure. [www.melisa.org and www.flcv.com/suscept.html]
The authors didn't bother to review the many hundreds of
studies which document the mechanisms by which mercury causes the conditions
seen in Alzheimer's, Parkinson's, multiple sclerosis, chronic fatigue, fibromyalgia, lupus,
Lou Gehrig's
Disease, etc. or the thousands of cases of recovery or significant improvement
from these conditions after treatment for mercury toxicity:
Alzheimer's: www.flcv.com/alzhg.html
Parkinson's www.flcv.com/parkins.html
other conditions www.flcv.com/indexa.html and www.melisa.org
*******************************************************
Regarding the authors statements on page 1733 discouraging
replacement of amalgam fillings, they don't bother to point out that when
amalgam fillings are replaced the increased exposure is temporary and limited
where properly done(as documented in the literature)
and that daily exposure levels are reduced 60 to 90 percent in the long run(as
documented in the literature) which has obvious benefits:
[L.Bjorkman et al, "Mercury
in Saliva and Feces after Removal of Amalgam Fillings", Toxicology and
Applied Pharmacology, 1997, 144(1), p156-62 &
G. Sandborgh-Englund et al,
Mercury in biological fluids after amalgam removal. J Dental Res, 1998, 77(4): 615-24;]
or
that peer reviewed studies and clinical studies document that thousands have recovered or had
significant improvement from serious chronic conditions after amalgam filling
replacement.
The authors statement that "there is no clear evidence
supporting the removal of amalgams" is obviously wrong and irresponsible,
since large numbers of peer-reviewed studies have documented
conditions where most who have
amalgams replaced recover, and thousands
are documented to have recovered from over 30 chronic conditions.
www.flcv.com/hgremove.html
www.flcv.com/amalg6.html
********************************************************
On page 1735 the authors in dealing with prenatal exposure
focus attention and limit discussion to methyl mercury. But it is well
documented in the literature that adverse developmental effects are more
common and occur at lower levels for mercury vapor exposure(as from
dental amalgam) than for methyl mercury.
(www.flcv.com/damspr13.html)
For example it is well documented that prenatal exposure to thimerosal(rhogam shots) and
dental amalgam from mothers are major factors in causation of autism
and other children's neurological developmental conditions.
[ A.S.
Holmes, M.F. Blaxill and B.E. Haley, Reduced Levels of
Mercury in First Baby Haircuts of Autistic Children; International Journal of Toxicology, 2003;
www.safeminds.org/ &
Metal-Metabolism and Autism: Defective Functioning of Metallothionein Protein, Amy Holmes, MD; http://www.healing-arts.org/children/metal-metabolism.htm
www.flcv.com/kidshg.html &
www.flcv.com/fetaln.html ]
****************************************************************
on
page 1735 the authors state that "it is reassuring that the only clinical
reports of mercury poisoning from fish consumption are those from
The authors appear to either not be very knowledgeable
about the medical literature regarding health effects from mercury or choose
for unknown reasons to ignore the overwhelming evidence since there are
extensive and well publicized studies and reports as well as Government panel
conclusions of adverse effects all over the world from mercury exposure through
eating fish and marine mammals that eat fish:
[(a)J.T. Salonen et al, "Intake of mercury from fish and the
risk of myocardial infarction and cardiovascular disease in eastern Finnish
men", Circulation, 1995; 91(3):645-55; &(
b) Wisconsin Bureau of Public Health,
Imported seabass as a source of mercury exposure: a
Wisconsin Case Study, Environ Health Perspect 1995,
103(6): 604-6; &
(c) Watanabe KH, Desimone
FW, Thiyagarajah A, Hartley WR, Hindrichs
AE. Fish tissue quality in the lower
(d) J. Hightower, "Methylmercury Contaminmation in
Fish: Human Exposures and Case Reports," Environmental Health
Perspectives;
(e) A Oskarsson
et al, Swedish National Food Administration, Mercury levels in hair from people
eating large quantities of Swedish freshwater fish. Food Addit
Contam 1990; 7(4):555-62; &
(f) Preventive Medicine February 2002;34:221-225; &
(g) Dickman MD;
Leung KM, "
(h)Mercury and organochlorine exposure from fish consumption in
(i) Y.Kinjo et al, "Cancer mortality in patients exposed
to methyl mercury through fish diet", J Epidemiol,
1996, 6(3):134-8; &
(j)
Choy C et al, Seafood consumption linked to infertility, BJOG: An International
Journal of Obstetrics & Gynaecology 2002
109:1121-5; & etc. & (www.flcv.com/flhg.html) &
(www.flcv.com/damspr16.html)]
******************************************************************************
On page 1735 the authors quote the
http://www.flcv.com/seychelr.html
Their main measure of mercury toxicity or exposure was hair
level, which is known for those who are affected most by mercury
exposure/toxicity to be inversely proportional to body burden and health
effects- the opposite from the authors assumptions-
and which led to seemingly strange results:
A.S. Holmes, M.F. Blaxill and B.E. Haley, Reduced Levels of Mercury in First Baby Haircuts of Autistic Children; International Journal of Toxicology, 2003, & Baby hair, mercury toxicity and autism. Int J Toxicol. 2004 Jul-Aug;23(4):275-6. Grether J, Croen L, Theis C, Blaxill M, Haley B, Holmes A.
Andrew Hall Cutler, PhD, PE; Amalgam
Illness:Diagnosis and Treatment; 1996 , www.noamalgam.com/
More details snipped from www.flcv.com/kidshg.html which has the references:)
A recent study found that prenatal mercury exposures and
susceptibility factors such as ability to excrete mercury appear to be a major
factors in those with chronic neurological conditions like autism(86).
Infants whose mothers received prenatal Rho D
immunoglobulin injections containing mercury thimerosal or whose mother's had
high levels of amalgam fillings had a much higher incidence of autism. While
the hair test levels of mercury of infants without chronic health conditions
like autism were positively correlated with the number of the mother's amalgam
fillings, vaccination thimerosal exposure, and mercury from fish, the hair test
levels of those with chronic neurological conditions such as autism were much
lower than the levels of controls and those with the most severe effects had
the lowest hair test levels, even though they had high body mercury levels.
This is consistent with past experience of those treating children with autism
and other chronic neurological conditions(23). Very
low levels of exposure have been found to seriously affect relatively large
groups of individuals who are immune sensitive to toxic metals(11,35), or have
an inability to detoxify metals due to such as deficient sulfoxidation
or metallothionein function(18,36,51) or other
inhibited enzymatic processes related to detoxification(15-24,30) or excretion
of metals(87). Those with the genetic allele ApoE4 protein in the blood have been
found to detox metals poorly and to be much more
susceptible to chronic neurological conditions than those with types ApoE2 or
E3(87). ]
(Note that while hair test mercury level is not a reliable
indicator of mercury body burden or mercury toxicity effects in those
susceptible to mercury toxicity effects, the hair test results are useful in
indicating those with mercury toxicity(23e). Since mercury toxicity affects
cell membrane permeability and essential mineral absorption and cellular
balance, a pattern of essential mineral imbalances in those with normal diets
is an indicator of mercury toxicity)
Andrew Hall Cutler, PhD, PE; Amalgam
Illness:Diagnosis and Treatment; 1996 , www.noamalgam.com/
Amy Holmes, MD, Baton Rouge Autism Treatment Clinic, http://www.flcv.com/autismc.html
*************************************
The last section of the paper on thimerosal effects is
poorly researched.
They state again that "methyl mercury is more
potent" than other forms, which is not supported by scientific evidence,
as previously seen. All of the forms are extremely toxic and are converted to
other forms in the body and no categorical statement can be supported of this
nature.
Studies in the previously referenced papers on
thimerosal/vaccine effects document that ethyl mercury has toxicity effects of
similar magnitude as methyl mercury, and that mercury vapor exposure has
developmental effects at lower levels of exposure than methyl mercury. The
authors state that since the half life of ethyl mercury in the blood is less
than that of methyl mercury, "risks of its damaging either the brain or
kidneys would seem remote". However there is no scientific evidence
supporting this conclusion and no plausible explanation of why they would think
so. Besides the fact that the conclusion of shorter half life in the blood does
not imply that body burden is less or decreased, as seen in the previously
referenced paper by Haley, Holmes, Blaxill; having a
shorter half life in the blood has no proven significance in the degree of
developmental damage by a highly toxic neurologic
substance. Mercury vapor, which has a far shorter half life in the blood, than
the other 2 forms, has the most developmental effects at lower levels of exposure as has
been documented here.
[www.flcv.com/damspr13.html]
Thomas W.
Clarkson, Ph.D., Environmental
Funding
for mercury in the
a
supplement to the JIFSAN Cooperative Agreement), with the Electric Power
Research
Institute
funding $486,000, the National Tuna Foundation funding $10,000, and the
National Fisheries Institute funding $5,000.
(http://web.archive.org/web/20010117171300/http://www.jifsan.umd.edu/Rev99AnRep.htm;
accessed
published comment on article :
Mutter J, Naumann J, Guethlin C.
Clarkson and Magos (2006) provide their perspectives on the toxicology of mercury vapor and dental amalgam. As scientists who are involved in preparing a German federal guideline regarding dental amalgam, we welcome additional scientific data on this issue. However, Clarkson and Magos do not present all the relevant studies in their review. The additional data provided here show that: (a) Dental amalgam is the main source of human total mercury body burden, because individuals with amalgam have 2-12 times more mercury in their body tissues compared to individuals without amalgam; (b) there is not necessarily a correlation between mercury levels in blood, urine, or hair and in body tissues, and none of the parameters correlate with severity of symptoms; (c) the half-life of mercury deposits in brain and bone tissues could last from several years to decades, and thus mercury accumulates over time of exposure; (d) mercury, in particular mercury vapor, is known to be the most toxic nonradioactive element, and is toxic even in very low doses, and (e) some studies which conclude that amalgam fillings are safe for human beings have important methodogical flaws. Therefore, they have no value for assessing the safety of amalgam
