Dear Dr.,

I have educated myself as best I can on the detoxification necessary for mercury amalgam removal. As you well know, this is an area with extreme critics.(1)

Since the majority of the population receives slightly less than a WHO established mercury dose weekly(2) and does not exhibit neurological issues(3), the amalgams are considered safe. As dentists are the principal critics, they ignore studies showing that although their mercury levels are "normal" they have increased memory disturbance and disorders of the kidney.(4) The criticism is particularly unscientific when rat studies on amalgams clearly show both the mercury and the silver in the amalgams cause severe medical issues.(5,6,7) It also flies in the face of a study showing that 70% of patients improve after amalgam removal.(8) These patients may display a: "V66M polymorphism in the gene encoding brain-derived neurotrophic factor (BDNF)."(9)

The initial DMSA provocation test has recently been disproved(10) as a legitimate marker for removal. It does not vary between sufferers and "healthy" volunteers, and may have serious side effects.(11) Rather than consider this a mark against amalgam removal or mercury toxicity, I would consider this confirmation that mercury has gone into the cells.(12) Mercury exposed workers also do not show an increased mercury load on provocation when the exposure is several years old. So although they have mercury in their systems, the provocation challenge is unsuccessful in provoking it.(13)

Instead of giving patients a three day test that is without justification in the standard medical model, I went looking for alternative testing. While I consider the cellular reactivity to mercury to be an interesting value, a recent study showed the immune cells to actually be less reactive.(14) While hair mercury levels are in common use, a study of dental workers found urine and fingernail clippings a much better marker of exposure.(15) I choose to monitor the acute mercury load on the individual using blood and urine markers.(16) Both of these are considered accurate measures of acute mercury exposure, and have been confirmed to increase with the addition of DMSA.(17)

In discussing the situation with my patients, they are against using DMSA, DMPS, or any other chemical to get rid of mercury, wondering exactly what the side effects are of long term use of these chemicals. This is a great concern to me, because in my experience what the patient perceives to be happening is as important as what is actually happening, particularly in those sensitive environmentally.(18) DMSA is considered the safest of the group,(19) but if I am to believe the manufacturer's precautions (Vital Nutrients DMSA), the side effects can be deadly. Although some doctors prefer DMPS, the standard is that both may be used interchangeably, and that neither is an ideal chelator for mercury.(20)

I question whether chronic chelation therapy is even necessary in a healthy individual, because those trying to kill themselves with mercury poisoning recover very quickly.(22,23,24) It seems clear from the ingestion of huge amounts of mercury that the response to mercury is genetically modified, and those individuals who are most sensitive to mercury are also more likely to experience chelation side effects.(25)

Chronic chelation has not been shown to remove brain mercury in rat models unless applied extremely aggressively (three times a week, I.V.). Discussion of the hydrophilic chelators DMPS and DMSA show that both are helpful at removing kidney level mercury, but are unable to effectively remove brain level mercury.(26) CaEDTA has been shown to be more effective at blocking neurotoxicity.(27) Barring the use of aggressive I.V. chelation, it seems wisest to monitor blood and urine for free mercury, and continue to supplement with selenium, which may be as effective as chelation for intracellular mercury. (See protocol below for endnotes)

In terms of amalgam removal, the best results clearly involve minimizing exposure to freed mercury. The mercury vapor being blocked by the use of rubber dams significantly lowers the mercury intake.(28) I also assume you are using a dry system, which has been shown to be more effective than a wet system.(29)

My current protocol is based on the existing data that I have and incorporates the manufacturer's protocol.

I am not specifically recommending certain supplements like Vitamin C, glutathione, or alpha lipoic acid, not because I am unaware of them, but because they have been shown to be ineffective in eliminating mercury from the brain or kidneys.(30)

For two weeks prior to mercury amalgam removal continuing for 19 days post removal, the patient will:

1) Avoid seafood (particularly freshwater, swordfish, or ground scavengers). The avoidance of seafood is part of any mercury detoxification as it provides a possible confounding source of mercury.(31, 32)
2) Take selenium, either as supplement or as garlic. Selenium has been shown to bind and coalesce mercury and other heavy metals intracellularly.(33) Selenomethionine has been shown to block the death of cells, so garlic or that in capsule form is preferred.(34)
3) Take ocimum sanctum extract, building up to 10mg/kg. This has been shown in mouse studies to protect against mercury induced liver damage.(35)
4) Take mercurious 12C or 15C. The homeopathic has been shown to be active in the liver at 15C,(36) and does not cause aggravations after short term use.(37)
5) Take probiotics, particularly the bacillus species. (used to environmentally remove mercury).(38)
6) Increase water intake until urine is clear, not yellow.

Two days before the removal:
1) Add in vitamin C to bowel tolerance. The vitamin C lowers the pH of the bowel, increasing the binding activity of DMSA.
2) Ensure good bowel movement. Check using activated charcoal for bowel transit time.
3) Begin magnesium, molybdenum, zinc and manganese supplementation if not already doing so.
4) Ensure sufficient supplies of DMSA, activated charcoal and fiber is on hand, and that appointments have been made to get CMP and CBC levels two days after removal.

On the day of removal:
1) Prepare kit with ½ body weight in ounces of water, charcoal, and DMSA.
2) Immediately begin activated charcoal and water after removal.
3) Follow with 10mg/kg DMSA within an hour, repeated in the evening.
4) Increase magnesium, zinc, molybdenum and manganese.
5) Flush the system with vitamin C and fiber.

Two days after the removal:
1) Get urine and blood levels of mercury.
2) Continue DMSA and above protocol until mercury levels return to pre-removal levels. (Based on symptoms and reactions.)
3) Recheck levels per individual patient plan and continue to monitor until levels return to normal.

I welcome discussion about this plan, and hope that it meets your approval. I understand that it is a dramatic departure from the extended plans offered by other doctors, but I have based it upon the most current available evidence.


Christopher Maloney, N.D.

1 Ned Tijdschr Tandheelkd. 1994 Oct;101(10):398-402.
[Amalgam. XVIII. Group characteristics in the attitude to and perception of amalgam]

[Article in Dutch]

Schuurs AH, Hoogstraten J, Eijkman MA.

Vakgroep Cariologie & Endodontologie, Academisch Centrum Tandheelkunde (ACTA), Louwesweg 1, 1066 EA Amsterdam.

Based upon their answers to a questionnaire, 1147 respondents could be divided into four groups. One group has a critical attitude to amalgam, the second is 'uncritical', the third 'uninformed' and the fourth, among which many with health complaints attributed to amalgam fillings, is named 'imaginary group'. The division is based upon nine out of 15 variables: 1. potential harmfulness of amalgam; 2. worry about the general health because of amalgam; 3. attribution of existing health complaints to amalgam; 4. reading/hearing about harmfulness of amalgam; 5. visits to alternative healers and quacks; 6. knowing that fish contains mercury; 7. knowing that amalgam contains mercury; 8. opinions on homeopathic medicines; 9. presence of dental amalgam. Among others preventive health and environmental actions were not of importance. The respondents, distinguished by sex, age and education, are not evenly distributed. An analysis of a second sample is considered in general to corroborate the findings. Although the analysis cannot reveal causal relationships, the results suggest the possibility that the population is kidded into distrust towards amalgam by the mass media and alternative healers.

PMID: 11831176 [PubMed - indexed for MEDLINE]

2 Occup Environ Med. 2004 Jun;61(6):535-40.
Evaluation of the mercury exposure of dental amalgam patients by the Mercury Triple Test.

Hansen G, Victor R, Engeldinger E, Schweitzer C.

Laboratoire d'Hygiene du Milieu et de Surveillance Biologique, Laboratoire National de Sante, Luxembourg. gilbert.hansen@lns.etat.lu

AIMS: To establish and analyse reference data for the mercury burden of patients with and without amalgam fillings. METHODS: Atomic absorption spectroscopy was used to quantify Hg concentrations in the scalp hair and urine (before and after application of dimercaptopropane sulphonate), and Hg release from dental amalgams (using a newly developed, amalgam specific chew test), in 2223 subjects. RESULTS: 50th centiles were 1.3 microg Hg/g creatinine in basal urine, 32 microg Hg/g creatinine after DMPS application, 454 ng Hg/g in hair, and 27 microg Hg per g of chewing gum, which corresponds to about 1 micro g Hg released per minute of chewing. Total Hg intake (from ambient air, drinking water, food, and amalgams) of most patients is well below the provisioned tolerable weekly intake (PTWI) defined by the WHO, unless extremely Hg rich food is consumed on a regular basis. However, for patients exceeding the 75th centile in chew tests, total Hg intake exceeds the PTWI by about 50%, even at the low limit of intake from food. In the absence of occupational exposure, significant Hg release from dental amalgams is a necessary but insufficient condition to obtain a high long term body burden. After removal of dental amalgams, chew tests no longer exhibit oral Hg exposure, while basal urine Hg content and DMPS induced excretion display a exponential decrease (half life about 2 months in both cases). CONCLUSIONS: A standardised procedure for evaluation of the magnitude and origin of the Hg burden of individuals has been developed, which, by comparison with the database presented here for the first time, can serve as a diagnostic tool.

3 Environ Health Perspect. 2003 May;111(5):719-23.
Mercury derived from dental amalgams and neuropsychologic function.

Factor-Litvak P, Hasselgren G, Jacobs D, Begg M, Kline J, Geier J, Mervish N, Schoenholtz S, Graziano J.

Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York 10032, USA. prf1@columbia.edu

There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, yet little evidence to support their harm or safety. We examined whether mercury dental amalgams are adversely associated with cognitive functioning in a cross-sectional sample of healthy working adults. We studied 550 adults, 30-49 years of age, who were not occupationally exposed to mercury. Participants were representative of employees at a major urban medical center. Each participant underwent a neuropsychologic test battery, a structured questionnaire, a modified dental examination, and collection of blood and urine samples. Mercury exposure was assessed using a) urinary mercury concentration (UHg); b) the total number of amalgam surfaces; and c) the number of occlusal amalgam surfaces. Linear regression analysis was used to estimate associations between each marker of mercury exposure and each neuropsychologic test, adjusting for potential confounding variables. Exposure levels were relatively low. The mean UHg was 1.7 micro g/g creatinine (range, 0.09-17.8); the mean total number of amalgam surfaces was 10.6 (range, 0-46) and the mean number of occlusal amalgam surfaces was 6.1 (range, 0-19). No measure of exposure was significantly associated with the scores on any neuropsychologic test in analyses that adjusted for the sampling design and other covariates. In a sample of healthy working adults, mercury exposure derived from dental amalgam restorations was not associated with any detectable deficits in cognitive or fine motor functioning.

PMID: 12727600 [PubMed - indexed for MEDLINE]

4 Occup Environ Med. 2002 May;59(5):287-93.
Comment in:
Occup Environ Med. 2002 May;59(5):285-6.

Health and neuropsychological functioning of dentists exposed to mercury.

Ritchie KA, Gilmour WH, Macdonald EB, Burke FJ, McGowan DA, Dale IM, Hammersley R, Hamilton RM, Binnie V, Collington D.

Institute of Hearing Research (Scottish Section), Glasgow Royal Infirmary, Glasgow, Scotland, UK. karen@ihr.gla.ac.uk

OBJECTIVES: A cross sectional survey of dentists in the west of Scotland and unmatched controls was conducted to find the effect of chronic exposure to mercury on health and cognitive functioning. METHODS: 180 dentists were asked to complete a questionnaire that included items on handling of amalgam, symptoms experienced, possible influences on psychomotor function, and the 12 item general health questionnaire. Dentists were asked to complete a dental chart of their own mouths and to give samples of urine, hair, and nails for mercury analysis. Environmental measurements of mercury in dentists' surgeries were made and participants undertook a package of computerised psychomotor tests. 180 control subjects underwent a similar procedure, completing a questionnaire, having their amalgam surfaces counted, giving urine, hair, and nail samples and undergoing the psychomotor test package. RESULTS: Dentists had, on average, urinary mercury concentrations over four times that of control subjects, but all but one dentist had urinary mercury below the Health and Safety Executive health guidance value. Dentists were significantly more likely than control subjects to have had disorders of the kidney and memory disturbance. These symptoms were not significantly associated with urinary mercury concentration. Differences were found between the psychomotor performance of dentists and controls after adjusting for age and sex, but there was no significant association between changes in psychomotor response and mercury concentrations in urine, hair, or nails. CONCLUSIONS: Several differences in health and cognitive functioning between dentists and controls were found. These differences could not be directly attributed to their exposure to mercury. However, as similar health effects are known to be associated with mercury exposure, it would be appropriate to consider a system of health surveillance of dental staff with particular emphasis on symptoms associated with mercury toxicity where there is evidence of high levels of exposure to environmental mercury.

PMID: 11983843 [PubMed - indexed for MEDLINE]

5 J Trace Elem Med Biol. 2001;15(1):1-4.
Elimination of mercury from amalgam in rats.

Galic N, Prpic-Mehiic G, Prester LJ, Krnic Z, Blanusa M, Erceg D.

Department of Dental Pathology, School of Dentistry, Zagreb, Croatia.

The aim of this study was to measure the urinary mercury excretion in rats exposed to amalgam over a two months period. Animals were either exposed to mercury from 4 dental amalgams or fed the diet containing powdered amalgams. The results showed significantly higher mercury amount in urine of both exposed groups than in control. Even two months after the amalgam had been placed in rats teeth, the amount of mercury in the urine remained 4-5 times higher than in control, and 4 times higher than in rats exposed to diet containing powdered amalgam. The elevated urinary Hg amount was accompanied by an increased level of total protein in urine. In the same exposure period the excretion of total protein in urine of rats with amalgam fillings was 2 times higher than in control and 1.5 times higher than in rats exposed to amalgam through diet. Concentrations of mercury in the sera of all groups were below the detection limit of the method. The results show that amount of mercury and protein in the urine of rats were related to the mercury release from dental malgam.

PMID: 11603820 [PubMed - indexed for MEDLINE]

6 FASEB J. 1994 Nov;8(14):1183-90.

Adverse immunological effects and autoimmunity induced by dental amalgam and alloy in mice.

Hultman P, Johansson U, Turley SJ, Lindh U, Enestrom S, Pollard KM.

Department of Pathology, Linkoping University, Sweden.

Dental amalgam fillings are the most important source of mercury exposure in the general population, but their potential to cause systemic health consequences is disputed. In this study, inbred mice genetically susceptible to mercury-induced immune aberrations were used to examine whether dental amalgam may interfere with the immune system and cause autoimmunity. Female SJL/N mice were implanted in the peritoneal cavity with 8-100 mg silver amalgam or silver alloy for 10 weeks or 6 months. Chronic hyperimmunoglobulinemia, serum IgG autoantibodies targeting the nucleolar protein fibrillarin, and systemic immune-complex deposits developed in a time- and dose-dependent manner after implantation of amalgam or alloy. Splenocytes from mice implanted with amalgam or alloy showed an increased expression of class II molecules. The functional capacity of splenic T and B cells was affected in a dose-dependent way: 10 weeks of low-dose and 6 months of high-dose amalgam implantation strongly increased mitogen-induced T and B cell proliferation, whereas 10 weeks of high-dose implantation decreased the proliferation. Not only mercury but also silver accumulated in the spleen and kidneys after amalgam implantation. In conclusion, dental amalgam implantation in a physiological body milieu causes chronic stimulation of the immune system with induction of systemic autoimmunity in genetically sensitive mice. Implantation of silver alloy not containing mercury also induced autoimmunity, suggesting that other elements, especially silver, have the potential to induce autoimmunity in genetically susceptible vertebrates. Accumulation of heavy metals, from dental amalgam and other sources, may lower the threshold of an individual metal to elicit immunological aberrations. We hypothesize that under appropriate conditions of genetic susceptibility and adequate body burden, heavy metal exposure from dental amalgam may contribute to immunological aberrations, which could lead to overt autoimmunity.

PMID: 7958626 [PubMed - indexed for MEDLINE]

7 J Dent Res. 1998 Jun;77(6):1415-25.
Activation of the immune system and systemic immune-complex deposits in Brown Norway rats with dental amalgam restorations.

Hultman P, Lindh U, Horsted-Bindslev P.

Department of Health and Environment, Linkoping University, Sweden.

Dental amalgam restorations are a significant source of mercury exposure in the human population, but their potential to cause systemic health effects is highly disputed. We examined effects on the immune system by giving genetically mercury-susceptible Brown Norway (BN) rats and mercury-resistant Lewis (LE) rats silver amalgam restorations in 4 molars of the upper jaw, causing a body burden similar to that described in human amalgam-bearers (from 250 to 375 mg amalgam/kg body weight). BN rats with amalgam restorations, compared with control rats given composite resinous restorations, developed a rapid activation of the immune system, with a maximum 12-fold increase of the plasma IgE concentration after 3 wks (p < 0.001; Mann-Whitney's test). LE rats receiving amalgam restorations showed no significant increase of plasma IgE (p > 0.05). After 12 wks, BN rats with amalgam restorations showed significantly increased (p < 0.05) titers of immune-complex (IC) deposits in the renal glomeruli and in the vessel walls of internal organs. These rats also showed a significant (p < 0.05), from six- to 130-fold, increase in tissue mercury concentration in the concentration order kidney > spleen > cerebrum occipital lobe > cerebellum > liver > thymus, and the tissue silver concentration was significantly (p < 0.05) increased from three- to 11-fold. Amalgam-implanted BN rats showed a significant (p < 0.05) increase in copper concentration in the kidney and spleen, and in kidney selenium concentration. We conclude that dental amalgam restorations release substantial amounts of their elements, which accumulate in the organs and which, in genetically susceptible rats, give rise to activation of the immune system and systemic IC deposits.

PMID: 9649170 [PubMed - indexed for MEDLINE]

8 Neuroendocrinol Lett. 2002 Oct-Dec;23(5-6):459-82.
Removal of dental amalgam and other metal alloys supported by antioxidant therapy alleviates symptoms and improves quality of life in patients with amalgam-associated ill health.

Lindh U, Hudecek R, Danersund A, Eriksson S, Lindvall A.

Department of Oncology, Radiology and Clinical Immunology, Rudbeck Laboratory, SE-751 85 Uppsala, Sweden. Ulf.Lindh@bms.uu.se

OBJECTIVES: The purpose of this study was to evaluate treatment of patients suffering from chronic ill health with a multitude of symptoms associated with metal exposure from dental amalgam and other metal alloys. SETTING AND DESIGN: We included 796 patients in a retrospective study using a questionnaire about symptom changes, changes in quality of life as a consequence of treatment and assessment of care taking. METHODS: Treatment of the patients by removal of offending dental metals and concomitant antioxidant therapy was implemented according to the Uppsala model based on a close co-operation between physicians and dentists. RESULTS: More than 70% of the responders, remaining after exclusion of those who had not begun or completed removal, reported substantial recovery and increased quality of life. Comparison with similar studies showed accordance of the main results. Plasma concentrations of mercury before and after treatment supported the metal exposure to be causative for the ill health. MAIN FINDINGS: Treatment according to the Uppsala model proved to be adequate for more than 70% of the patients. Patients with a high probability to respond successfully to current therapy might be detected by symptom profiles before treatment. CONCLUSIONS: The hypothesis that metal exposure from dental amalgam can cause ill health in a susceptible part of the exposed population was supported. Further research is warranted to develop laboratory tests to support identification of the group of patients responding to current therapy as well as to find out causes of problems in the group with no or negative results.

PMID: 12500173 [PubMed - indexed for MEDLINE]

9 Toxicol Sci. 2004 Oct;81(2):354-63. Epub 2004 Jul 14.

Chronic low-level mercury exposure, BDNF polymorphism, and associations with self-reported symptoms and mood.

Heyer NJ, Echeverria D, Bittner AC Jr, Farin FM, Garabedian CC, Woods JS.

Battelle Centers for Public Health Research and Evaluation, Seattle, Washington, USA.

Recent reports have described neurobehavioral impairments in human subjects carrying a V66M polymorphism in the gene encoding brain-derived neurotrophic factor (BDNF). Inasmuch as ventral nervous system (CNS) deficits associated with this BDNF polymorphism are similar to those observed among subjects with chronic exposure to elemental mercury (Hg degrees ), we examined the potential effect of this BDNF polymorphism on symptoms and mood in an established cohort of dental practitioners with chronic low-level Hg degrees exposure. Self-reported symptoms and mood were obtained by computerized questionnaire from 193 male dentists (DTs) and 230 female dental assistants (DAs). Spot urine samples were analyzed for mercury concentrations to evaluate recent exposure. Detailed work histories were obtained to calculate chronic indices of Hg degrees exposure. Buccal cell samples were obtained to identify the V66M polymorphism of BDNF. Scores for 11 current and 12 recent and chronic symptom groups, along with six mood factors, were evaluated with respect to recent and chronic Hg degrees exposure and BDNF polymorphism. Multiple regression analysis controlled for age, race, socioeconomic status, tobacco and alcohol use, self-reported health problems, and medications. Separate evaluations were conducted for DTs and DAs. Twenty-three associations between recent or chronic Hg degrees exposure and BDNF status and self-reported symptoms were observed with p < 0.10. All but three were in the expected direction (symptom scores increasing with Hg degrees exposure or BDNF polymorphism), and all but six were among DAs. All eight correlations between chronic exposure indices and recent and chronic symptoms among DAs were in the expected direction. All seven associations between BDNF and symptoms were in the expected direction and split between DTs and DAs. All three associations with mood factors were among DAs and in the expected direction. These results indicate that among DAs very low levels of occupational Hg degrees exposure are associated with increased symptoms. The BDNF polymorphism is also associated with increased symptom and mood scores. Notably, Hg degrees and BDNF polymorphism were additive with respect to their associations with the same symptom group.

PMID: 15254338 [PubMed - indexed for MEDLINE]

10 Sci Total Environ. 2003 Jun 1;308(1-3):63-71.
Blood mercury following DMPS administration to subjects with and without dental amalgam.

Vamnes JS, Eide R, Isrenn R, Hol PJ, Gjerdet NR.

Department of Odontology-Dental Biomaterials, University of Bergen, Aarstadveien 17, N-5009 Bergen, Norway. jan.vamnes@odont.uib.no

The use of DMPS as a diagnostic tool in patients with symptoms allegedly caused by mercury from dental amalgam fillings is disputed. We have previously shown that the mercury concentrations in urine cannot be used in such a way. In the present study, we wished to evaluate the effect on blood mercury levels (B-Hg) following intravenously injected DMPS in four groups of subjects: 19 controls without amalgam experience; 21 healthy controls with amalgam fillings; 20 patients with self-reported symptoms from existing dental amalgams; and 20 patients who had removed amalgam fillings. A single dose of DMPS (2 mg/kg) was injected. Blood samples were collected prior to the injection and after 15, 30, 120 min, and after 24 h, and mercury was analyzed by cold vapor atomic absorption spectrophotometry. All groups showed an initial drop of 24 to 30% in the blood levels, approaching baseline values (2.5-5.5 microg/l) after 2 h. The subjects with no amalgam experience had the lowest mercury values. There was no significant difference between the three groups with such experience. There were no significant differences between the two groups with amalgam fillings present. Patients with symptoms allegedly caused by amalgam were not different from the control groups. There were indications that part of the urinary mercury excreted during the first 30 min originated from blood.

Publication Types:

* Clinical Trial


PMID: 12738201 [PubMed - indexed for MEDLINE]

11 Ann Clin Biochem. 2004 May;41(Pt 3):233-6.
Comment in:

* Ann Clin Biochem. 2004 Sep;41(Pt 5):421-2; author reply 423.
* Ann Clin Biochem. 2004 Sep;41(Pt 5):422-3; author reply 423.

Click here to read
Dimercaptosuccinic acid loading test for assessing mercury burden in healthy individuals.

Archbold GP, McGuckin RM, Campbell NA.

Department of Clinical Biochemistry, Belfast City Hospital, Belfast BT9 7AD, Northern Ireland, UK. pooler.archbold@bll.n-i.nhs.uk

BACKGROUND: Oral chelation tests have been used to try to define mercury toxicity in individuals with dental amalgams, who are suffering from a variety of non-specific symptoms. METHODS: Self-reported healthy individuals volunteered to undergo an oral chelation test using dimercaptosuccinic acid (DMSA) at a dose of 30 mg/kg body weight. Urinary mercury : creatinine ratios were measured pre-dose and 3 h post-dose. RESULTS: Urinary mercury : creatinine ratios were similar to levels previously reported in individuals with symptoms that could have been attributed to mercury toxicity. One volunteer suffered a serious reaction to DMSA. CONCLUSION: The oral chelation test using DMSA may lead to misleading diagnostic advice regarding potential mercury toxicity and can be associated with serious side effects.

12 Clin Chem Lab Med. 2001 Feb;39(2):134-42.

Metal exposure from amalgam alters the distribution of trace elements in blood cells and plasma.

Lindh U, Carlmark B, Gronquist SO, Lindvall A.

Department of Oncology, Uppsala University, Sweden. Ulf.Lindh@bms.uu.se

Twenty-seven consecutive patients with health problems associated with dental amalgam were recruited. In spite of thorough medical examinations, there were no diagnoses available. The patient group was dominated by women. A healthy age- and sex-matched control group with dental amalgams without symptoms was also recruited. Metal level monitoring in plasma and nuclear microscopy of isolated individual blood cells were carried out. Significant increases of copper, iron, zinc and strontium were found in patient plasma. There was no significant difference in plasma selenium between the groups. Mercury was significantly increased in patient plasma, although there was overlap between the groups. In erythrocytes a significant increase in calcium and a significant decrease in magnesium, copper, manganese and zinc were found. Calcium, magnesium, manganese and copper increased in patient neutrophil granulocytes. A significant decrease was found for zinc. A conspicuous finding was the presence of measurable mercury in a few of the cells from the patient but not in the control group. Thus, nuclear microscopy of isolated individual blood cells might provide a better diagnostic tool for metal exposure than blood plasma measurements.

PMID: 11341747 [PubMed - indexed for MEDLINE]

13 Environ Health Perspect. 2001 Feb;109(2):167-71.
Diagnostic chelation challenge with DMSA: a biomarker of long-term mercury exposure?

Frumkin H, Manning CC, Williams PL, Sanders A, Taylor BB, Pierce M, Elon L, Hertzberg VS.

Department of Environmental and Occupational Health, Emory University, Atlanta, Georgia, USA. medhf@sph.emory.edu

Chelation challenge testing has been used to assess the body burden of various metals. The best-known example is EDTA challenge in lead-exposed individuals. This study assessed diagnostic chelation challenge with dimercaptosuccinic acid (DMSA) as a measure of mercury body burden among mercury-exposed workers. Former employees at a chloralkali plant, for whom detailed exposure histories were available (n = 119), and unexposed controls (n = 101) completed 24-hr urine collections before and after the administration of two doses of DMSA, 10 mg/kg. The urinary response to DMSA was measured as both the absolute change and the relative change in mercury excretion. The average 24-hr mercury excretion was 4.3 microg/24 hr before chelation, and 7.8 microg/24 hr after chelation. There was no association between past occupational mercury exposure and the urinary excretion of mercury either before or after DMSA administration. There was also no association between urinary mercury excretion and the number of dental amalgam surfaces, in contrast to recent published results. We believe the most likely reason that DMSA chelation challenge failed to reflect past mercury exposure was the elapsed time (several years) since the exposure had ended. These results provide normative values for urinary mercury excretion both before and after DMSA challenge, and suggest that DMSA chelation challenge is not useful as a biomarker of past mercury exposure.

PMID: 11266328 [PubMed - indexed for MEDLINE]

14 J Dent. 2001 Sep;29(7):469-74.
Mercury-reactive lymphocytes in peripheral blood are not a marker for dental amalgam associated disease.

Henderson DC, Clifford R, Young DM.

Imperial College School of Medicine, Department of Immunology, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK.

OBJECTIVES: The popular press and publications associated with alternative medicine increasingly report that chronic ill health, particularly myalgic encephalitis like conditions, are associated with mercury amalgam fillings. There are no scientifically proven definitive tests to support these claims. One of the more scientific tests in vogue is to assess the level of blood-borne mercury-reactive lymphocytes and to conclude that patients with high levels have developed a hypersensitivity reaction to mercury. The objective of this study was to determine the diagnostic value of this test. METHODS: This study represents an open comparison of mercury-reactive lymphocyte levels in healthy control individuals with those in patients complaining of symptoms associated with adverse effects of dental metal amalgam fillings. The healthy control group consisted of 51 male and female individuals, aged between 12 and 82 years, with and without dental amalgam fillings. The patient group consisted of 70 male and female individuals, aged between 12 and 87 years, and with the exception of one patient, with three or more mercury amalgam fillings of more than 1 year's duration. In vitro lymphocyte responses to mercury, and to nickel, as an example of a metal commonly associated with hypersensitivity reactions, and to more conventional protein antigens were determined. RESULTS: In the blood of patients and controls, there were similar levels of specifically reactive lymphocytes to all of the in vitro stimulating agents, but there were significantly higher numbers of sub-normal and non-responders within the patient group. CONCLUSIONS: The incidence and quantity of mercury-reactive lymphocytes in the blood are not pathogenic markers of illness associated with dental metal amalgams, but may rather reflect exposure to mercury. The clinical relevance of the decreased in vitro lymphocyte responses in the patient group needs further investigation.

PMID: 11809324 [PubMed - indexed for MEDLINE]

15 Biomarkers. 2004 Jan-Feb;9(1):47-55.
Comparison of hair, nails and urine for biological monitoring of low level inorganic mercury exposure in dental workers.

Morton J, Mason HJ, Ritchie KA, White M.

Health and Safety Laboratory Sheffield, UK. jackie.morton@hsl.gov.uk

Creatinine-corrected urine mercury measurements in spot urine samples are routinely used in monitoring workers exposed to inorganic mercury. However, mercury measurement in other non-invasive biological material has been used in some epidemiological studies. Dentists and dental nurses remain a group of workers with potential exposure to inorganic mercury through their handling of mercury-containing amalgam, although changes in work practices have reduced the current, likely exposure to mercury. Therefore, dental workers remain an occupational cohort in whom the value of using different biological media to identify exposure to low level inorganic mercury can be investigated. Samples of head hair, pubic hair, fingernails, toenails and urine were analysed for mercury content from a cohort of UK dentists (n=167) and a socioeconomically similar reference population (n=68) in whom any mercury exposure was primarily through diet. The mercury content in all biological material was significantly higher in the dental workers than in the control population (p<0.0001). The geometric mean and 90th percentile mercury concentrations in the urine samples from dentists were 1.7 and 7.3 micromol mol(-1) creatinine, respectively, with only one sample having a value at around the UK's Health and Safety Executive biological monitoring health guidance level of 20 micromol mol(-1) creatinine. Receiver operator characteristic analyses suggested that the ability of the biological material to discriminate between dentists and referents were fingernails>urine approximately equal to toenails>pubic hair approximately equal to head hair. Further investigation is warranted as to why fingernails appear to be such a good discriminator, possibly reflecting some contribution of direct finger contact with amalgam or contaminated surfaces rather than systemic incorporation of mercury into growing nails. Good correlation between head hair and pubic hair mercury levels in all subjects was obtained (r=0.832), which was significantly improved when hair samples weighing <10 mg were excluded (r=0.868). Therefore, under these exposure conditions and using the described pre-analytical washing steps, there is little influence from atmospheric contamination on the level of mercury content of head hair. The choice of non-invasive biological materials for mercury analysis depends on a number of considerations. These include the toxicokinetics of urinary mercury excretion, the growth rates of hair and nail, the nature and time-frame of exposure, and the fact that urine mercury may not reflect the body burden level from dietary methyl mercury. However, the data from this study suggests that urine mercury remains the most practical and sensitive means of monitoring low level occupational exposure to inorganic mercury.

PMID: 15204310 [PubMed - indexed for MEDLINE]

16 Environ Health Perspect. 2000 Jun;108(6):575-7.
A cluster of pediatric metallic mercury exposure cases treated with meso-2,3-dimercaptosuccinic acid (DMSA)

Forman J, Moline J, Cernichiari E, Sayegh S, Torres JC, Landrigan MM, Hudson J, Adel HN, Landrigan PJ.

Department of Pediatrics, Mount Sinai School of Medicine, New York, New York 10029-6574, USA. joelforman@bigfoot.com

Nine children and their mother were exposed to vapors of metallic mercury. The source of the exposure appears to have been a 6-oz vial of mercury taken from a neighbor's home. The neighbor reportedly operated a business preparing mercury-filled amulets for practitioners of the Afro-Caribbean religion Santeria. At diagnosis, urinary mercury levels in the children ranged from 61 to 1,213 microg/g creatinine, with a geometric mean of 214.3 microg/m creatinine. All of the children were asymptomatic. To prevent development of neurotoxicity, we treated the children with oral meso-2,3-dimercaptosuccinic acid (DMSA). During chelation, the geometric mean urine level rose initially by 268% to 573.2 microg mercury/g creatinine (p<0.0005). At the 6-week follow-up examination after treatment, the geometric mean urine mercury level had fallen to 102.1 microg/g creatinine, which was 17.8% of the geometric mean level observed during treatment (p<0.0005) and 47.6% of the original baseline level (p<0.001). Thus, oral chelation with DMSA produced a significant mercury diuresis in these children. We observed no adverse side effects of treatment. DMSA appears to be an effective and safe chelating agent for treatment of pediatric overexposure to metallic mercury.

Publication Types:

* Case Reports
* Clinical Conference


PMID: 10856034 [PubMed - indexed for MEDLINE]

17 Med Lav. 2003 Mar-Apr;94(2):231-41.

[Significance of biological indicators of mercury exposure]

[Article in Italian]

Apostoli P, Mangili A, Alessio L.

Cattedra di Igiene Industriale, Universita degli Studi di Brescia, p.le Spedali Civili 1, 25123 Brescia.

BACKGROUND: It was considered appropriate to update of the significance and use of the different mercury exposure indicators. OBJECTIVE: The aim of the this paper was to correctly select biological media and sampling time and to understand the toxic kinetics of mercury for assessment of accurate biological monitoring. RESULTS: It was confirmed that mercury in blood (B-Hg) is a good indicator of recent exposure, while urinary mercury (U-Hg) indicates current exposure when mercury reaches the renal steady state. B-Hg values are greatly influenced by fish consumption, while the variables influencing U-Hg values are amalgam fillings, commercial gamma-globulin preparations, vaccines, topical remedies, environmental pollution and hobbies, occupational exposure and, partly, fish consumption. The speciation of mercury (Hg0, Hg++, methylmercury and ethylmercury) in biological media, should provide additional and important information in evaluating mercury toxicity. CONCLUSION: It was stressed that the appropriate choice of exposure indicators has to take account of the different variability factors and the characteristics of the toxic kinetics of mercury. The results of biological monitoring must be compared with references values, which are generally in the order of several micrograms/g creatinine, and limit values such as ACGIH BEI (U-Hg 35 micrograms/g creatinine and B-Hg 15 micrograms/l) or the DFG BAT (U-Hg 100 micrograms/l and B-Hg 25 micrograms/l).

Publication Types:
Review
Review, Tutorial

PMID: 12852206 [PubMed - indexed for MEDLINE]

18 J Occup Environ Med. 1997 Aug;39(8):707-14.
Placebo response in environmental disease. Chelation therapy of patients with symptoms attributed to amalgam fillings.

Grandjean P, Guldager B, Larsen IB, Jorgensen PJ, Holmstrup P.

Department of Environmental Medicine, Odense University, Denmark.

Treatment of patients who attribute their environmental illness to mercury from amalgam fillings is largely experimental. On the Symptom Check List, overall distress, and somatization, obsessive-compulsive, depression, and anxiety symptom dimensions, were increased in 50 consecutive patients examined, and Eysenck Personality Questionnaire scores suggested less extroversion and increased degree of emotional liability. Succimer (meso-2, 3-dimercaptosuccinic acid) was given at a daily dose of 30 mg/kg for five days in a double-blind, randomized placebo-controlled trial. Urinary excretion of mercury and lead was considerably increased in the patients who received the chelator. Immediately after the treatment and 5 to 6 weeks later, most distress dimensions had improved considerably, but there was no difference between the succimer and placebo groups. These findings suggest that some patients with environmental illness may substantially benefit from placebo.

Publication Types:

* Clinical Trial
* Randomized Controlled Trial


PMID: 9273873 [PubMed - indexed for MEDLINE]

19 Altern Med Rev. 1998 Jun;3(3):199-207.
Dimercaptosuccinic acid (DMSA), a non-toxic, water-soluble treatment for heavy metal toxicity.

Miller AL.

Alternative Medicine Review. P.O. Box 25, Dover, ID 83825, USA. alan@thorne.com

Heavy metals are, unfortunately, present in the air, water, and food supply. Cases of severe acute lead, mercury, arsenic, and cadmium poisoning are rare; however, when they do occur an effective, non-toxic treatment is essential. In addition, chronic, low-level exposure to lead in the soil and in residues of lead-based paint, to mercury in the atmosphere, in dental amalgams and in seafood, and to cadmium and arsenic in the environment and in cigarette smoke is much more common than acute exposure. Meso-2,3-dimercaptosuccinic acid (DMSA) is a sulfhydryl-containing, water-soluble, non-toxic, orally-administered metal chelator which has been in use as an antidote to heavy metal toxicity since the 1950s. More recent clinical use and research substantiates this compound s efficacy and safety, and establishes it as the premier metal chelation compound, based on oral dosing, urinary excretion, and its safety characteristics compared to other chelating substances.

Publication Types:

* Review
* Review, Tutorial


PMID: 9630737 [PubMed - indexed for MEDLINE]

20 Curr Opin Pediatr. 1999 Jun;11(3):265-8.
Treatment of mercury intoxication.

Baum CR.

Division of Emergency Medicine, Children's Memorial Hospital, Chicago, IL 60614, USA. c-baum@nwu.edu

The element mercury exists as inorganic, elemental, or organic species. Routes of exposure and toxicity in humans vary according to the species of mercury involved. Treatment of mercury poisoning generally requires the use of sulfhydryl bond-containing chelation agents, including the parenterally administered dimercaprol and its oral congeners. These oral chelators, meso-2,3-dimercaptosuccinic acid and sodium 2,3-dimercapto-1-propanesulfonate, have numerous advantages over dimercaprol, including less toxicity. Although dimercaprol is contraindicated in organic mercury exposures, meso-2,3-dimercaptosuccinic acid and sodium 2,3-dimercapto-1-propanesulfonate may be used to chelate all species of mercury. Recent evidence suggests that their efficacy in organic mercury poisoning is uncertain.

Publication Types:

* Review


PMID: 10349108 [PubMed - indexed for MEDLINE]

21 Chem Res Toxicol. 2004 Aug;17(8):999-1006.
Mercury binding to the chelation therapy agents DMSA and DMPS and the rational design of custom chelators for mercury.

George GN, Prince RC, Gailer J, Buttigieg GA, Denton MB, Harris HH, Pickering IJ.

Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada. g.george@usask.ca

Clinical chelation therapy of mercury poisoning generally uses one or both of two drugs--meso-dimercaptosuccinic acid (DMSA) and dimercaptopropanesulfonic acid (DMPS), commercially sold as Chemet and Dimaval, respectively. We have used a combination of mercury L(III)-edge X-ray absorption spectroscopy and density functional theory calculations to investigate the chemistry of interaction of mercuric ions with each of these chelation therapy drugs. We show that neither DMSA nor DMPS forms a true chelate complex with mercuric ions and that these drugs should be considered suboptimal for their clinical task of binding mercuric ions. We discuss the design criteria for a mercuric specific chelator molecule or "custom chelator", which might form the basis for an improved clinical treatment.

PMID: 15310232 [PubMed - indexed for MEDLINE]

22 J Toxicol Clin Toxicol. 1996;34(4):453-60.
Clinical course of severe poisoning with thiomersal.

Pfab R, Muckter H, Roider G, Zilker T.

Walther-Straub-Institut fur Pharmakologie und Toxikologie, Universitat Munchen, Germany.

CASE REPORT: A 44-year-old man ingested 83 mg/kg Thiomersal. He developed gastritis, renal tubular failure, dermatitis, gingivitis, delirium, coma, polyneuropathy and respiratory failure. Treatment was symptomatic plus gastric lavage and the oral chelating agents dimercaptopropane sulfonate and dimercaptosuccinic acid. The patient recovered completely. Maximum mercury concentrations were blood 14 mg/L, serum 1.7 mg/L, urine 10.7 mg/L, and cerebrospinal fluid 0.025 mg/L. Mercury concentration in blood declined with two velocities: first with half-time 2.2 days, then with half-time 40.5 days. The decline of mercury concentration in blood, urinary mercury excretion, and renal mercury clearance were not substantially influenced by chelation therapy.

Publication Types:

* Case Reports


PMID: 8699562 [PubMed - indexed for MEDLINE]

23 J Toxicol Clin Toxicol. 2001;39(7):733-8.
Intravenous mercury injection and ingestion: clinical manifestations and management.

McFee RB, Caraccio TR.

The Long Island Regional Poison Control Center, Winthrop University Hospital, Mineola, New York 11501, USA.

BACKGROUND: Mercury is a complex toxin with clinical manifestations determined by the chemical form, route, dose, and acuity of the exposure. Parenteral injection of elemental mercury remains uncommon. CASE REPORT: A 40-year-old male injected 3 mL of elemental mercury intravenously and ingested 3 mL as a suicide attempt. Within 24 hours, he became dyspneic, febrile, tachycardic, and voiced mild gastrointestinal complaints. Chest X-ray revealed scattered pulmonary infiltrates and embolized mercury bilaterally. A ventilation/perfusion scan demonstrated ventilation/ perfusion deficits. Additionally, his renal function declined, as manifest by minor elevations in blood urea nitrogen and creatinine and decreased urine output. Pulmonary therapy, intravenous hydration, and chelation using 2,3-dimercaptoscuccinic acid (DMSA/Succimer) were started. Over the next 36 hours, the patient's pulmonary and renal functions improved. Temperature and heart rate subsequently normalized, and symptoms at discharge were mild exertional dyspnea. DISCUSSION: Liquid mercury injected intravenously embolizes to the pulmonary vasculature and perhaps vessels in other organs such as heart and kidney. In-situ oxidation to inorganic mercury, which is directly toxic to a variety of tissues, may help explain the multisystem involvement. CONCLUSION: Significant pulmonary dysfunction accompanied by radiographically demonstrated mercury emboli and temporary abnormalities in several organs improved shortly after initiation of chelation. The impact of chelation on long-term outcome of parenteral mercury exposure remains uncharacterized.

Publication Types:

* Case Reports


PMID: 11778672 [PubMed - indexed for MEDLINE]

24 Ann Emerg Med. 2002 Mar;39(3):312-5.
Mercuric oxide poisoning treated with whole-bowel irrigation and chelation therapy.

Ly BT, Williams SR, Clark RF.

Division of Medical Toxicology, Department of Emergency Medicine, University of California San Diego Medical Center, San Diego Division, San Diego, CA 92103, USA. bly@ucsd.edu

Most reported cases of inorganic mercury poisoning are from mercuric chloride. We report a case of mercuric oxide (HgO) powder ingestion. A 31-year-old man presented to an emergency department after ingestion of approximately 40 g of HgO. Soon after ingestion, he developed nausea, vomiting, and abdominal cramping. Abdominal radiograph revealed densely radiopaque material in the stomach. Gastrointestinal decontamination was accomplished with activated charcoal and whole-bowel irrigation with polyethylene glycol solution (Golytely) for 24 hours until repeat abdominal radiographs no longer demonstrated the substance in the gastrointestinal tract. He was also chelated with British anti-Lewisite for 5 days, followed by succimer for 10 days. He had markedly elevated urine and blood mercury levels after ingestion, but except for a mildly depressed serum bicarbonate (19 mEq/L), his chemistry results remained normal including blood urea nitrogen and creatinine. He had an uncomplicated hospital course and remained asymptomatic at 6 months postingestion. Despite elevated urine and blood mercury levels after ingestion of HgO, our patient did not develop the end-organ toxicity typical of inorganic mercury poisoning.

Publication Types:
Case Reports

PMID: 11867987 [PubMed - indexed for MEDLINE]

25 Int Arch Allergy Immunol. 1995 Mar;106(3):180-203.

Does amalgam affect the immune system? A controversial issue.

Enestrom S, Hultman P.

Department of Pathology I, Linkoping University, Sweden.

Although in use for more than 150 years, dental amalgam has been questioned more or less vigorously as a dental restoration material due to its alleged health hazard. Humans are exposed to mercury and the other main dental amalgam metals (Ag, Sn, Cu, Zn) via vapour, corrosion products in swallowed saliva, and direct absorption into the blood from the oral cavity. Dental amalgam fillings are the most important source of mercury exposure in the general population. Local, and in some instances, systemic hypersensitivity reactions to dental amalgam metals, especially mercury, occur at a low frequency among amalgam bearers. Experimental and clinical data strongly indicate that these and other subclinical systemic adverse immunological reactions to dental amalgam metals in humans will be linked to certain MHC genotypes, and affect only a small number of the exposed individuals. These individuals will be very difficult to detect in a mixed population of susceptible and resistant individuals, including persons with alleged symptoms due to dental amalgam fillings, where many of the individuals are likely to suffer from conditions with no proven immunological background such as multiple chemical sensitivity syndrome. Intensified studies should be performed to identify such susceptible MHC genotypes, taking advantage of the reported cases of more heavily metal-exposed humans with systemic autoimmune reactions. Further studies will also be needed to ascertain whether the combined exposure to the metals in dental amalgam may lower the threshold for adverse immunological reactions, since recent studies have shown that the metals in alloy, especially silver, may induce autoimmunity in genetically susceptible mice.

Publication Types:
Review
Review, Academic

PMID: 7888781 [PubMed - indexed for MEDLINE]

26 Environ Health Perspect. 2002 Oct;110 Suppl 5:887-90.

Molecular mechanisms of in vivo metal chelation: implications for clinical treatment of metal intoxications.

Andersen O, Aaseth J.

Department of Life Sciences and Chemistry, Roskilde University, Postbox 260, 4000 Roskilde, Denmark. Andersen@ruc.dk

Successful in vivo chelation treatment of metal intoxication requires that a significant fraction of the administered chelator in fact chelate the toxic metal. This depends on metal, chelator, and organism-related factors (e.g., ionic diameter, ring size and deformability, hardness/softness of electron donors and acceptors, route of administration, bioavailability, metabolism, organ and intra/extracellular compartmentalization, and excretion). In vivo chelation is not necessarily an equilibrium reaction, determined by the standard stability constant, because rate effects and ligand exchange reactions considerably influence complex formation. Hydrophilic chelators most effectively promote renal metal excretion, but they complex intracellular metal deposits inefficiently. Lipophilic chelators can decrease intracellular stores but may redistribute toxic metals to, for example, the brain. In chronic metal-induced disease, where life-long chelation may be necessary, possible toxicity or side effects of the administered chelator may be limiting. The metal selectivity of chelators is important because of the risk of depletion of the patient's stores of essential metals. Dimercaptosuccinic acid and dimercaptopropionic sulfonate have gained more general acceptance among clinicians, undoubtedly improving the management of many human metal intoxications, including lead, arsenic, and mercury compounds. Still, development of new safer chelators suited for long-term oral administration for chelation of metal deposits (mainly iron), is an important research challenge for the future.

Publication Types:
Review
Review, Tutorial

PMID: 12426153 [PubMed - indexed for MEDLINE]

27 J Dent Res. 2003 Mar;82(3):243-6.
Neurotoxicity of dental amalgam is mediated by zinc.

Lobner D, Asrari M.

Department of Biomedical Sciences, Marquette University, 561 N. 15th Street, Rm. 426, Milwaukee, WI 53201, USA. Doug.Lobner@marquette.edu

The use of dental amalgam is controversial largely because it contains mercury. We tested whether amalgam caused toxicity in neuronal cultures and whether that toxicity was caused by mercury. In this study, we used cortical cell cultures to show for the first time that amalgam causes nerve cell toxicity in culture. However, the toxicity was not blocked by the mercury chelator, 2,3-dimercaptopropane-1-sulphonate (DMPS), but was blocked by the metal chelator, calcium disodium ethylenediaminetetraacetate (CaEDTA). DMPS was an effective mercury chelator in this system, since it blocked mercury toxicity. Of the components that comprise amalgam (mercury, zinc, tin, copper, and silver), only zinc neurotoxicity was blocked by CaEDTA. These results indicate that amalgam is toxic to nerve cells in culture by releasing zinc. While zinc is known to be neurotoxic, ingestion of zinc is not a major concern because zinc levels in the body are tightly regulated.

PMID: 12598557 [PubMed - indexed for MEDLINE]

28 Dent Mater. 1997 Sep;13(5):297-304.
Mercury levels in plasma and urine after removal of all amalgam restorations: the effect of using rubber dams.

Berglund A, Molin M.

Department of Dental Materials Science, Umea University, Sweden. Anders.Berglund@denmatsc.umu.se

OBJECTIVE: The aim of the present study was to determine whether removal of all amalgam restorations might significantly affect mercury levels in plasma and urine and whether the use of rubber dams might reduce patient exposure to mercury during amalgam removal. METHODS: All amalgam restorations were removed from 18 subjects during a single treatment session in which a rubber dam was used and from 10 subjects when a rubber dam was not used. All amalgam restorations were removed by the same dentist using high-speed cutting, water coolant, and high-volume evacuation. The levels of mercury in plasma and urine were analyzed both before and during the subsequent twelve months after amalgam removal. In order to determine whether removal of all amalgam restorations might cause an exposure large enough to significantly increase the mercury levels in two indicator media for mercury exposure, i.e., plasma and urine, and to determine if the removal might cause a significant decrease in the mercury levels found over time, the one-tailed, paired Students' t-test was used. For each individual, the pre-removal levels were compared with both the levels found in plasma on d 1 and in urine on d 10, and also with the levels found 1 y after removal. Furthermore, in order to examine whether the use of rubber dams had any effect on the mercury levels found after removal, the changes in the mercury levels found were compared between the groups using the Wilcoxon-Mann-Whitney rank sum test. RESULTS: After removal of all amalgam restorations, only the non-rubber dam group showed significant increases in the mercury levels found in plasma (p = 0.012) and urine (p = 0.037). However, one year later, the mercury levels in plasma and urine had sunk significantly below the pre-removal levels for both groups. When the changes in the mercury levels found were compared between the groups, the non-rubber dam group showed a significantly higher increase of mercury in plasma than the rubber dam group the day after removal (p = 0.0010). Compared to the pre-removal mercury levels in plasma and urine, the levels found 1 y after removal of all amalgam restorations were on average 52 +/- 23% (range 4-89%) lower in plasma and 76 +/- 21% (range 20-94%) lower in urine. SIGNIFICANCE: The study showed that dental amalgam had a statistically significant impact on the mercury levels found in plasma and urine in the patients tested, and that the use of a rubber dam during removal of all amalgam restorations significantly reduced the peak of mercury in plasma following removal.

PMID: 9823089 [PubMed - indexed for MEDLINE]

29 J Oral Rehabil. 2004 Aug;31(8):822-6.
Effectiveness of wet and dry mercury vapour suppressant systems in a faculty of dentistry clinic.

Sutow EJ, Hall GC, MacLean CA.

Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada. elliott.sutowdal.ca

The objective of this study was to determine the effectiveness of a liquid and a dry commercial mercury vapour suppressant system. Measurements were made in a student dental clinic, using a mercury vapour detector for periods up to 76 weeks. The two products examined were Mercon vap liquid in a stock jar and the Mercon tainer dry jar system. Amalgam scrap jars were removed from the study when the mercury vapour concentration in the jars exceeded the arbitrary cut-off criterion of 0.05 mg Hg m(-3). Results showed that the mercury vapour concentration in the liquid system exceeded the cut-off criterion in 44 weeks or less, whereas the dry system remained below the detection limit (0.01 mg Hg m(-3)) for the maximum measurement period of 76 weeks. It was concluded that the dry system is more effective and reliable than the liquid system. The reliability of the liquid system may be influenced by contact of amalgam scrap with the portion of the inner wall of the jar that is not covered by liquid. It is proposed that amalgam scrap contaminates the wall with mercury during its insertion. Copyright 2004 Blackwell Publishing Ltd.

PMID: 15265221 [PubMed - indexed for MEDLINE]

30 J Toxicol Clin Toxicol. 2003;41(4):339-47.
Vitamin C, glutathione, or lipoic acid did not decrease brain or kidney mercury in rats exposed to mercury vapor.

Aposhian HV, Morgan DL, Queen HL, Maiorino RM, Aposhian MM.

Department of Molecular and Cellular Biology, The University of Arizona, Tucson, Arizona 85721-0106, USA. aposhian@u.arizona.edu

Some medical practitioners prescribe GSH and vitamin C alone or in combination with DMPS or DMSA for patients with mercury exposure that is primarily due to the mercury vapor emitted by dental amalgams. HYPOTHESIS: This study tested the hypothesis that GSH, vitamin C, or lipoic acid alone or in combination with DMPS or DMSA would decrease brain mercury. METHODS: Young rats were exposed to elemental mercury by individual nose cone, at the rate of 4.0 mg mercury per m3 air for 2 h per day for 7 consecutive days. After a 7-day equilibrium period, DMPS, DMSA, GSH, vitamin C, lipoic acid alone, or in combination was administered for 7 days and the brain and kidneys of the animals removed and analyzed for mercury by cold vapor atomic absorption. RESULTS: None of these regimens reduced the mercury content of the brain. Although DMPS or DMSA was effective in reducing kidney mercury concentrations, GSH, vitamin C, lipoic acid alone, or in combination were not. CONCLUSION: One must conclude that the palliative effect, if any, of GSH, vitamin C, or lipoic acid for treatment of mercury toxicity due to mercury vapor exposure does not involve mercury mobilization from the brain and kidney.

PMID: 12870874 [PubMed - indexed for MEDLINE]

31 J Am Acad Dermatol. 2003 Dec;49(6):1109-11.

A new cutaneous sign of mercury poisoning?

Dantzig PI.

Department of Dermatology, Columbia University School of Medicine, 30 E. 60th Street, Suite 705, New York, NY 10022, USA. pidmd@aol.com

Chronic mercury poisoning is becoming a health concern because of extensive pollution of water and fish, and the increasing consumption of fish in the human diet. Mercury is extremely toxic to the body, especially the central nervous system, but diagnosis is difficult because of the lack of specific signs. A total of 11 patients were observed to have a nonpruritic or mildly pruritic discreet papular and papulovesicular eruption that correlated with high blood mercury levels. The mercury evidently came from increased seafood consumption. All of the patients improved when they were placed on either a seafood-free diet or chelation therapy. Physicians should suspect mercury poisoning in patients who eat a high-seafood diet who present with an asymptomatic or mildly pruritic papular or papulovesicular eruption.

PMID: 14639393 [PubMed - in process]

32 J Occup Environ Med. 2002 Feb;44(2):143-54.
Mercury exposure: current concepts, controversies, and a clinic's experience.

Kales SN, Goldman RH.

Cambridge Health Alliance, Harvard Medical School, Harvard School of Public Health, Department of Environmental Health (Occupational Health Program), Cambridge, MA, USA. stefokali@aol.com

In the context of controversies surrounding fish consumption, amalgams, and commercial hair testing, we reviewed all cases from an occupational and environmental medicine clinic that had undergone mercury testing. Sixty-nine of 71 (97%) patients had no known mercury exposures other than diet or amalgams. Of these 69, 48 had blood mercury tested and 58 had urine testing. Regular-to-heavy fish consumption explained 10 of 11 cases with blood mercury concentrations > 15 micrograms/L (19 to 53 micrograms/L). Six of these 10 individuals reported regular swordfish consumption. For the 31 patients with adequate dietary history, there was a significant relationship between fish consumption and blood mercury concentration (P < 0.001). Higher blood mercury concentrations were, however, not associated with specific patterns of health complaints. Ninety-eight percent (57 of 58) of urine values were < 10 micrograms/L. Fourteen patients were evaluated because they were labeled as mercury toxic by other practitioners after unconventional commercial testing. Using standard tests of blood and urine, we could not document evidence of mercury toxicity in any of these 14 cases. We conclude that consumption of commercially available fish can lead to elevated blood mercury concentrations. A recognized exposure source is a better predictor of significant mercury concentrations in biologic media than any particular symptom constellation. Unconventional commercial panels that test hair or urine for multiple metals have questionable validity. Clinicians should use standard blood and urine tests to evaluate mercury exposure.

Publication Types:

* Review
* Review, Tutorial


PMID: 11851215 [PubMed - indexed for MEDLINE]

33 Cell Mol Biol (Noisy-le-grand). 1996 Feb;42(1):39-48.
Selenium protection against toxicity from cadmium and mercury studied at the cellular level.

Lindh U, Danersund A, Lindvall A.

Division of Biomedical Radiation Sciences, Uppsala University, Sweden.

Interaction between selenium and the heavy metals cadmium and mercury was studied in an experimental rat model (Sprague-Dawley). The rats were administered either one single trace element or combinations of selenium and cadmium as well as selenium and mercury. Salts of these trace elements were administered intraperitoneally daily during thirty days. Thereafter the animals were sacrificed and kidneys and livers excised rapidly. Thin sections were produced by a cryotome and subsequently freeze-dried. Nuclear microscopy of the sections showed that in the combination groups there was a co-localization of selenium and the heavy metals. None of the expected pathological signs of cadmium and mercury toxicity were observed. The conclusion was that selenium exerted a protective effect against the toxicity of cadmium and mercury through mechanisms still to be unveiled.

PMID: 8833665 [PubMed - indexed for MEDLINE]

34 Biol Trace Elem Res. 2003 May;92(2):105-14.
Selenium protection against mercury-induced apoptosis and growth inhibition in cultured K-562 cells.

Frisk P, Wester K, Yaqob A, Lindh U.

Department of Oncology, Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University, Sweden.

Selenium and mercuric chloride (MC) interactions regarding effects on cell growth and cell death have been studied. Human K-562 cells were pretreated or simultaneously treated with either selenite (5 or 50 microM) or selenomethionine (10 or 50 microM) and with MC (35 or 50 microM). The 35-microM MC treatments resulted in a clear inhibition of cell growth with no obvious difference between mercury-treated and mercury-selenium-treated cells. Furthermore, the apoptotic frequency was similar at all observations for all selenium treatments with 35 microM MC. In the simultaneously treated selenite and 50- microM MC combinations, a selenite-dependent protection was shown both by increased cell growth and by lower apoptotic frequency at 48 and 96 h of exposure. Both treatments with selenomethionine showed protection observed as an increased cell growth at 48 and 96 h and as decreased apoptotic frequency at 96 h of exposure.

PMID: 12746570 [PubMed - in process]

35 Indian J Exp Biol. 2002 Sep;40(9):1079-82.
Ocimum sanctum aqueous leaf extract provides protection against mercury induced toxicity in Swiss albino mice.

Sharma MK, Kumar M, Kumar A.


Department of Zoology, University of Rajasthan, Jaipur, 302 004, India.

HgCl2 (5.0 mg/kg body weight) induced toxicity led to significant elevation of lipid peroxidation (LPO) level but decline in the glutathione content in liver of Swiss albino mice. In serum of HgCl2 treated mice there was significant elevation in serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) activities but significant decline in the alkaline phosphatase activity. Animals treated with O. sanctum extract (10 mg/kg body weight, po) before and after mercury intoxication showed a significant decrease in LPO level, SGOT and SGPT activities and increase in serum alkaline phosphatase activity and glutathione (GSH) content. Ocimum treatment alone did not alter SGOT, SGPT and alkaline phosphatase activities but significantly enhanced reduced glutathione. The results suggest that oral administration of Ocimum extract provides protection against HgCl2 induced toxicity in Swiss albino mice.

PMID: 12587743 [PubMed - indexed for MEDLINE]

36 Dtsch Tierarztl Wochenschr. 1993 Dec;100(12):485-7.

[Different effects of homeopathic potencies and conventional dilutions on specific liver enzymes of rats--an in vivo study]

[Article in German]

Theenhaus U, Dittmann J, Harisch G.

Institut fur Physiologische Chemie, Tierarztlichen Hochschule Hannover.

It was searched for differing effects of homeopathic potencies and equally concentrated conventional dilutions. Activities of enzymes from three different subcellular compartments of the rat liver served as parameters for the evaluation. Especially in the D15/10(-15) range differences proved to be statistically relevant. The series with potentiated carrier substance, necessary from heuristic reasons and related to the homeopathic potencies, resulted in hitherto not understandable findings.

PMID: 8306867 [PubMed - indexed for MEDLINE]

37 J Altern Complement Med. 2001 Apr;7(2):141-8.
J Altern Complement Med. 2001 Apr;7(2):123-5.

Can homeopathically prepared mercury cause symptoms in healthy volunteers? A randomized, double-blind placebo-controlled trial.

Vickers AJ, van Haselen R, Heger M.

Royal London Homoeopathic Hospital, England, United Kingdom.

OBJECTIVE: To pilot a method for determining whether homeopathically prepared mercury causes more symptoms (a "drug proving") in healthy volunteers than placebo. METHODS: One hundred and eighteen (118) healthy volunteers ages 18 to 65 were recruited by local advertising. Subjects unfamiliar with homeopathy undertook a 1-week single-blind placebo run-in, a 1-week of double-blind, randomized treatment on either homeopathically prepared mercury 12C or placebo, and a third week of placebo run-out. Each day, symptoms were recorded on a checklist that included both true mercury symptoms and symptoms not expected to be caused by mercury (false symptoms). Additional symptoms were assessed by open reporting. Outcome was assessed by calculating a score for each day as the number of true symptoms minus the number of false symptoms. The mean score during placebo was then subtracted from the mean score for weeks two and three of the trial. RESULTS: Fourteen (14) subjects dropped out during placebo run-in. The remaining 104 completed the trial. Baseline comparability was good. Mean difference score was -0.125 (SD 3.47) for mercury and -0.221 (SD 3.01) for placebo (p > 0.2). No significant differences between groups were found for the number of subjects meeting predefined criteria for a drug-proving reaction. CONCLUSION: This pilot study failed to find evidence that mercury 12C causes significantly more symptoms in healthy volunteers than placebo. Questionnaires with a limited number of gross symptoms do not seem to be an appropriate methodological technique in drug proving research. If drug-proving phenomena exist, they appear to be rare.

Publication Types:
Clinical Trial
Randomized Controlled Trial

PMID: 11327520 [PubMed - indexed for MEDLINE]

38 Med Hypotheses. 2002 May;58(5):382-5.
Probiotics as an adjuvant to detoxification protocols.

Brudnak MA.

MAK Wood Inc, Grafton, Wisconsin 53024-9429, USA. Mark.Brudnak@usc.alumni.edu

Autism is a developmental disease characterized by a spectrum of symptoms ranging from decreased verbal skills and social withdrawal, to repetitive behavior and violent outbursts. Genetic analysis has yielded a few potentially interesting genes, however no clear linkage has been established. For this reason, it has been suggested that the etiology of autism may involve multiple loci. This, in large part, explains why so many different theories abound. One such theory is that of mercury poisoning. Environmentally acquired mercury, either through some causal contact or through vaccination, has been postulated as the culprit. Mercury is thought to be exerting its neurological effect on the brain. The standard treatment has been to apply chelating agents in an attempt to extricate the mercury. One missing component in the treatment is the utilization of the body's own detoxification mechanisms. Arguably the largest detoxification component of the body, the endogenous enteric bacteria are an enormous reservoir, which can be constantly and safely replenished. This paper discusses the use of high-dose probiotics as an adjuvant for detoxification protocols with an emphasis on use in autistics. Copyright 2002 Published by Elsevier Science Ltd.

Publication Types:

* Review
* Review, Tutorial


PMID: 12056873 [PubMed - indexed for MEDLINE]