Comments on Children’s Amalgam Study one (and study 2):

"Neurological and Renal Effects of Dental Amalgam in Children", D.C. Bellinger et al, JAMA, April 10, 2006

by: B. Windham,  Research Director and President,   DAMS, Intl.    12164 Whitehouse Rd, Tallahassee, Fl 32317



The study design has been documented to not have been a serious effort to determine amalgam safety in children, as the design was badly flawed and could not in its form determine the safety of amalgam fillings. As documented here, the study was an unethical use of a known highly toxic substance on children who were not fully informed or in a position to understand the implications.  But the authors’ interpretation of results is also questionable, since the study is here shown to not have been structured to assess the main known health effects related to mercury exposure from amalgam, and the authors disregarded the thousands of peer-reviewed studies that have previously documented the health harm caused by mercury, and the well documented fact that dental amalgam is the largest source of mercury exposure in most people with several amalgam fillings, as documented here.


It is known from thousands of studies and millions of tests by medical labs that dental amalgam is the largest source of mercury exposure in most adults and children who have several amalgam fillings, and that those with amalgam get significantly higher mercury exposure than those without(5,15), ;

that mercury accumulates in the brain and major organs proportionately to the number of amalgam fillings,

 and commonly causes chronic degenerative neurological conditions later in life(6-13,3).

Under the Proposition 65 procedures, passed by the state of California in 1986, mercury has been determined to be a reproductive toxin, and to cause birth defects (14). Many studies have also documented this (15).  Thus, products that use mercury and cause significant mercury exposure must provide warnings to the public of the known health risk (14).  Use of dental amalgam by dentists in California requires such a warning.  Several other states have passed similar laws requiring warnings by dentists of the known health risk related to use of dental amalgam.  Dental amalgam has been documented by tests at medical labs to be the largest source of mercury exposure for most people who have several amalgam fillings (5).  A mother’s dental amalgam has been documented to often be the largest source of mercury to the fetus and to young infants, with levels in the fetus and infant often higher than the mother’s blood level (15).


A study at the U.S. CDC found "statistically significant associations" between neurological   developmental disorders such as autism, attention deficit disorder(ADD) and speech disorders with exposure to mercury from thimerosal‑containing vaccines before the age of 6 months (16,17).  An analysis of the U.S. CDC VAERS database for adverse reactions from vaccines regarding effects of the diptheria-tetanus-pertusis vaccine found that those receiving DTaP and DTucP vaccines with thimerosal had significantly higher rates of autism, speech disorders, and heart arrest than those receiving DtaP vaccine without thimerosal, and that the rate of these increase exponentially with dose(18).  An analysis of the U.S. Dept. of Education report on the prevalence of various childhood conditions among school children found that the rate of autism and speech disorders increased with increasing levels of thimerosal exposure from vaccines (18).

        A followup study using DMSA as a chelator found that overall, urinary mercury concentrations were significantly higher in children with autistic spectrum disorders than in a matched control population, and that vaccinated cases showed significantly higher urinary mercury concentrations than vaccinated controls (18b). This is consistent with other studies that found that those who are poor excreters of mercury are more likely to accumulate mercury and have adverse health effects (6).  A significant portion of children and adults have been documented to have this problem due to blood allele type or metallothionein deficiencies.

            A study of environmental mercury levels in Texas school districts found a 61 percent increase in autism and a 43 percent increase in special education cases for every 1,000 pounds of mercury released into the environment (19a). Autism prevalence diminished by 2 percent for every 10 miles of distance from a mercury source.  Another similar study found similar results and estimated economic costs due to disability or lower IQ (19b).  Fossil fuel-burning power plants were the largest source of the widespread mercury pollution (19) but dental amalgam was the largest source in sewers and a significant source of environmental mercury in water bodies, fish, and air emissions (20).


Thus the ethics in the exposure to a group of children to higher levels of a very neurotoxic substance such as mercury is highly questionable, along with the fact that the study had no mechanism for assessing long-term accumulation of mercury in body organs, future cumulative mercury health effects, or synergistic effects with other future toxic exposures, which have been well documented in the medical literature (3-13).



This study was not a serious test of the safety of amalgam since the exposure was to children with no previous amalgam fillings at relatively low levels of exposure for a very limited period of time.  The mean number of restored amalgam surfaces in the mouth of the amalgam group at the end of the study was only 4 amalgam surfaces.   And while the urine mercury level in the amalgam group was 50% higher than the non-amalgam group, this is a much lower differential than most studies of groups or either children or adults with and without amalgams(15).


However, even with the low exposure levels, it is not clear from the study results that there were no significant adverse effects of amalgam shown as claimed by the authors.


For example, it is well documented that mercury from amalgam commonly causes chronic neurological conditions in adults.    So it might be useful to compare diagnosed neurological conditions between amalgam and non-amalgam group.   The comparison is as follows:


Condition                      amalgam group     non-amalgam group    percent difference

migraines                              18                        14                           28.5%

neurological illness                   4                          1                         300%

psychological disorders           24                        18                           33%

sensory disorders                   36                        28                          28.5%


Total                                     82                        51                           60%


Amalgam is also known to cause respiratory problems- the study found the following

Asthma                                19                         17                         13%

Respiratory disorders          13                          7                          86%


Total                                    32                         24                         33%


Similarly while the authors state that there were no significant renal effects observed,  it could be noted that the unadjusted mean albumin level at year 5 for the amalgam group was 38% higher than for the non-amalgam group.   I would be very concerned about the future of some at the high end of the amalgam group albumin levels.


Children’s Amalgam Study 2:

Comments on   “Neurobehavioral Effects of Dental Amalgam in Children”,   T. A. De Rouen, et al,   JAMA, April 19, 2006


That this study like the other children’s amalgam study, represented an unethical use of a known highly toxic and immune reactive substance on children, and was not designed to seriously have a chance of determining the long-term health effects of amalgam use has been documented in the comments on Study 1 in this paper.


In justifying the study design the author’s state on page 1 that “there is little or no evidence concerning health effects of low level mercury exposure from amalgam, especially in children”.   In fact, there are over 3,000 peer-reviewed studies in the medical literature(3,6-13) that were submitted by parties in the FDA amalgam docket to the FDA (4), that document the mechanisms by which mercury(from amalgam) accumulates in all major organs and commonly causes over 30 chronic health conditions.  And there are hundreds are peer-reviewed studies and clinical studies that document that many thousands of patients with these conditions have improved after amalgam replacement (2). While it is clear that hundreds of thousands (or millions) of children have had their health adversely affected by mercury, since there are multiple exposure mechanisms and synergistic effects with other toxic substances, so it’s not clear the extent to which dental amalgam is primarily responsible or just a contributor with other exposures (7,15,16-20).


But the main problem with the study design appears to be the choice of what conditions were tested for and the kinds of tests that were used.   In describing why the chosen conditions were tested for and in what manner, the authors stated on page 2 of the study that the target organs for elemental mercury exposure from amalgam were identified to be the renal system and neurological functions(memory, attention/concentration, and motor/visuomotor).  Actually, while there is documentation in the medical literature of many other types of health effects, there is little evidence in the literature on common renal effects.(1,2,3). And there are other types of health effects that have been well documented in the literature to be more commonly caused by mercury than attention or memory(though these also have been documented to be commonly caused by mercury exposure)(3,6-13).


The following analysis shows that the basic assumptions that the authors say they based their study design on were not valid, and the study does not demonstrate what it has been suggested to demonstrate.  In fact, due to the poor study design the study is not very useful.  It had been documented by millions of medical lab tests that those with amalgam fillings commonly have mercury exposures between 5 and 10 times that of the average person with no amalgams (5), and that mercury accumulates in the brain and major organs in direct proportion to the number of amalgam surfaces.  It has likewise been documented in the medical literature by thousands of studies that mercury and other toxic metals exposures are synergistic and cumulative, and commonly cause chronic autoimmune, neurological, hormonal, and reproductive problems later in life(3), depending on individual susceptibility(6).

Thus it was clear that the study design exposing children to a known highly neurotoxic and immunotoxic substance that commonly causes adverse effects was highly unethical.  And also, the effects that might happen in the early years of exposure has little relevance to whether amalgam is safe as a filling material.  The study was not designed to determine anything about the long term health or safety effects on this population of children.  Or even on the most common types of conditions known to be commonly caused by dental amalgam or the types of cardiovascular effects found in a similar test of children from the Faeroe Islands.


Questionnaire results of 1569 patients (1) regarding health problems that have been documented to be commonly caused by mercury toxicity found the following distribution:


Condition                    % with Condition          %  improved after Amalgam Replacement


Fatigue/lack of energy (12)    51%                                        86%

Headaches/migraines (8)      37%                                         87%

Allergy/skin conditions (10)  34%                                        84%

Vision Problems                    29%                                        63%

Cardiovascular problems(9)   27%                                        70% 

(tachycardia/irregular heartbeat/

  high blood pressure/chest pain)

Depression/anxiety    (11)    27%                                        90%

Dizzyness(could be cardio)   22%                                        88%

Oral conditions         (13)     20%                                        85%

ADD/lack of concentration    17%                                        80%

Memory Loss            (8)       17%                                        73%

MS/Parkinson’s/tremor  (10) 15%                                        78%


Similar patterns and recovery results after amalgam filling replacement have also been documented in a larger group of over 60,000 patients(2).   Thousands of peer-reviewed studies documenting the mechanism by which mercury commonly causes these conditions are in the literature(3).   It is seen that there are 8 major types of health conditions known to be caused by mercury that are more commonly seen in the population than the  types of conditions that these studies chose to attempt to test for.


And in all of those types of conditions, peer-reviewed studies and clinical studies have found that the majority of those who had amalgam fillings replaced properly had health improvement after replacement.    There are few studies documenting significant renal effects from dental amalgam exposure, so it’s not clear why the authors chose to test for renal effects.  There is some question as to what the study being reviewed actually measured regarding neurological effects, since other studies have documented that mercury from amalgam and other toxic metals commonly cause ADD/attention deficit(7), as well as memory problems(perhaps more later in life)(8) and that the majority with such conditions usually improve after amalgam replacement.

        It should also be noted that since the effects of toxic exposures are known to be synergistic and cumulative, the results of a study in one country or population do not necessarily apply to another country or population- that has significantly different patterns of toxic exposures, such as the extremely high mercury thimerosal exposures to children in the U.S. in the 1990s which are documented to have significantly impacted that population(7).


(1)  Patterns of chronic conditions in 1569 patients and percent recovery after amalgam filling replacement,

(2) Results of amalgam filling replacement in over 60,000 patients monitored by peer-reviewed or clinical studies,

(3) Mechanisms by which mercury(from dental amalgam) commonly causes over 30 chronic health conditions (over 4,000 peer-reviewed & Gov’t studies cited),

(4) Listing and abstracts and compilation of medical studies submitted to the FDA dental amalgam safety docket,

(5) Dental amalgam is the largest source of both inorganic and methyl mercury in most people with dental amalgams,



(8) Mechanisms by which mercury is documented to cause neurological conditions, B Windham(Ed) –over 150 cites,

(9) Mechanisms by which mercury is documented to cause cardiovascular conditions, - over 150 cites,

(10) Mechanisms by which mercury is documented to cause

autoimmune/immune conditions, over 150 cites,

(11) Mechanisms by which mercury is documented to cause depression/mood disorders, over 100 cites,

(12) Mechanisms by which mercury is documented to cause

fatigue/CFS/FMS, over 150 cites,


(13) Mechanisms by which mercury is documented to cause oral conditions,  over 100 cites,

(14)    Laws of the State of California, Proposition 65, Safe Drinking Water and Toxic Enforcement Act of 1986.


(15) Effects of mercury from mother’s dental amalgam on the fetus and infants,  review, B.Windham (Ed), 2006.


 (16)  Dr Thomas Verstraeten,  US Centres for Disease  Control and Prevention, Summary Results: Vaccine Safety  Datalink Project ‑ a database of 400,000 children , May 2000.; & THE TRUTH BEHIND THE VACCINE COVER-UP, By Russell L. Blaylock, M.D.

(17) Geier M.R., Geier DA; Neurodevelopmental disorders following thimerosal-containing vaccines. Ex Biol Med, April 2003; & A comparative evaluation of the effects of MMR immunization and mercury doses from thimerosal-containing childhood vaccines on the population prevalence of autism.  Med Sci Monit. 2004 Mar;10(3):PI33-9. Epub 2004; Geier DA, Geier MR.

(18) Geier M.R., Geier DA; Thimerosal in Childhood Vaccines, Neurodevelopmental Disorders, and Heart Disease in the U.S. ; J of Amer Physicians and Surgeons, Vol 8(1), Spring 2003; & (b) Bradstreet J, Geier DA, et al,  A case control study of mercury burden in children with Autisitic Spectrum Disorders, J of Amer Physicians and Surgeons, Vol 8(3), Summer 2003; & (c) A case series of children with apparent mercury toxic encephalopathies manifesting with clinical symptoms of regressive autistic disorders. Geier DA, Geier MR. J Toxicol Environ Health A. 2007 May 15;70(10):837-51


(19) Environmental mercury release, special education rates, and autism disorder: an ecological study of Texas,  Health and Place,  R.F. Palmer et al, March 2005     &  Mercury pollution from power plants, NWF,

& (b) Mental retardation and prenatal methylmercury toxicity., Trasande L, Schechter CB, Haynes KA, Landrigan PJ., Department of Community and Preventive Medicine, Center for Children's Health and the Environment, New York, New York. Am J Ind Med. 2006 Mar;49(3):153-8,

(20) Dental amalgam is the largest source of mercury in sewers and a significant source of mercury in water bodies, fish, and the environment,  EPA &