Preliminary Comments on “Neurobehavioral Effects of Dental Amalgam in Children”, T. A. De Rouen, et al, JAMA, April 19, 2006
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) that were submitted by parties in the FDA amalgam docket to the FDA (4), that document the mechanisms by which mercury(from amalgam) 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 its not clear the extent to which dental amalgam is responsible(7).
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).
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,
http://www.home.earthlink.net/~berniew1/hgrecovp.html(2) Results of amalgam filling replacement in over 60,000 patients monitored by peer-reviewed or clinical studies,
http://www.home.earthlink.net/~berniew1/hgremove.html(3) Mechanisms by which mercury(from dental amalgam) commonly causes over 30 chronic health conditions (over 4,000 peer-reviewed & Gov’t studies cited),
http://www.home.earthlink.net/~berniew1/indexa.html(4) Listing and abstracts and compilation of medical studies submitted to the FDA dental amalgam safety docket,
http://www.flcv.com/fdatally.htmlhttp://www.flcv.com/fdarev.htmlhttp://www.flcv.com/fdarevl.html(5) Dental amalgam is the largest source of both inorganic and methyl mercury in most people with dental amalgams,
http://www.home.earthlink.net/~berniew1/damspr1.html(6)
http://www.home.earthlink.net/~berniew1/suscept.html(7)
http://www.flcv.com/tmlbn.html http://www.flcv.com/kidshg.html http://www.flcv.com/autismc.html(8) Mechanisms by which mercury is documented to cause neurological conditions, B Windham(Ed) –over 150 cites,
http://www.home.earthlink.net/~berniew1/neurohg.html(9) Mechanisms by which mercury is documented to cause cardiovascular conditions, - over 150 cites,
http://www.home.earthlink.net/~berniew1/cardio.html(10) Mechanisms by which mercury is documented to cause
autoimmune/immune conditions, over 150 cites,
http://www.home.earthlink.net/~berniew1/ms.htmlhttp://www.home.earthlink.net/~berniew1/immunere.html(11) Mechanisms by which mercury is documented to cause depression/mood disorders, over 100 cites,
http://www.home.earthlink.net/~berniew1/depress.html(12) Mechanisms by which mercury is documented to cause
fatigue/CFS/FMS, over 150 cites,
http://www.home.earthlink.net/~berniew1/cfsfm.html(13) Mechanisms by which mercury is documented to cause oral conditions, over 100 cites,
http://www.home.earthlink.net/~berniew1/periodon.html