Mercury

“We determined the exposure to mercury from dental amalgam by comparison of blood levels of mercury before and after removal of all amalgams from ten subjects. Baseline concentrations of mercury in whole blood were measured weekly for four to 18 weeks (median = 6.6 weeks) prior to removal. All amalgams were removed in a single appointment. The subjects had an average of 14 surfaces of amalgam, seven of which were occlusal surfaces. Weekly blood sampling was continued for five to 18 weeks (median = 7.6 weeks) after the amalgams were removed. The mean baseline concentration of total mercury in whole blood of the ten subjects was 2.18 (SD = 0.90) ng Hg/mL before the amalgams were removed. The baseline mercury levels were related to the number of amalgam surfaces. The linear correlation coefficient was 0.724 with number of occlusal surfaces, and 0.433 with total number of surfaces. After removal of the amalgams, nine of the ten subjects exhibited a statistically significant decrease in blood mercury at the 95% level of confidence. The mean decrease in mercury was 1.13 (SD = 0.60) ng Hg/mL. The half-time for elimination of mercury from blood after amalgam removal was 30.2 (SD = 5.8) days. Removal of the amalgams provided an additional exposure of 1.46 (SD = 1.17) ng Hg/mL that was rapidly cleared from the blood with a half-time of 2.9 days. The daily intake of mercury from amalgam in the subjects was estimated to be at least 1.3 micrograms.”

“The findings presented here suggest that mercury poisoning from dental amalgam may play a role in the etiology of mental illness. Comparisons between subjects with and without amalgam showed significant differences in subjective reports of mental health. Subjects who had amalgams removed reported that symptoms of mental illness lessened or disappeared after removal. The data suggest that inorganic mercury poisoning from dental amalgam does affect the mind and emotions.”

The DMPS mobilization test is suited for assaying reserves of mercury in the human organism.  Replicable and mutually comparable results are attainable only through standardization of test conditions.

“Four chemical preservatives commonly used in ophthalmic solutions were tested for their toxic and mutagenic potential in mouse lymphoma cells with and without exposure of the cells to ultraviolet A (UVA) radiation. The preservatives tested were benzalkonium chloride (BAK), chlorhexidine, thimerosal and ethylenediaminetetraacetic acid (EDTA). Cell survival and mutagenesis were measured using the L5178Y mouse lymphoma (TK +/-) system. Cells were exposed to varying amounts of preservatives for 1 h at 37 degrees C, and then aliquots were irradiated with UVA radiation (during the exposure to preservative). Cells were then assayed for survival, and for mutagenesis at the thymidine kinase (TK) locus. In concentrations commonly found in ophthalmic solutions, BAK, chlorhexidine, and thimerosal were toxic to cells, and thimerosal was slightly mutagenic. When cells were exposed to preservative and UVA radiation, chlorhexidine was mutagenic and the mutagenic activity of thimerosal was enhanced.”

“Analyses of mercury concentration have shown high concentrations of mercury in the pituitary glands of dental staff. By contrast with mercury (Hg), selenium (Se) is an essential trace element. After simultaneous administration to rats, Hg and Se have been reported to be associated with a single protein fraction in the plasma.”

“The potential hazards of metallic mercury in dentistry are well recognized. The present report concerns a patient who experienced an uncommonly high mercury exposure and, possibly, mercury-related toxicity from vapor released during extensive grinding of old amalgam fillings.”

“The fate of mercury (Hg) released from dental ‘silver’ amalgam tooth fillings into human mouth air is uncertain. A previous report about sheep revealed uptake routes and distribution of amalgam Hg among body tissues. The present investigation demonstrates the bodily distribution of amalgam Hg in a monkey whose dentition, diet, feeding regimen, and chewing pattern closely resemble those of humans. When amalgam fillings, which normally contain 50% Hg, are made with a tracer of radioactive 203Hg and then placed into monkey teeth, the isotope appears in high concentration in various organs and tissues within 4 wk. Whole-body images of the monkey revealed that the highest levels of Hg were located in the kidney, gastrointestinal tract, and jaw. The dental profession’s advocacy of silver amalgam as a stable tooth restorative material is not supported by these findings.”

The various defects in cell-mediated immunity in psoriasis might also involve a loss of tolerance to nickel, high levels of which have been detected in psoriatic keratin (I). No data is available on the frequency of nickel sensitivity in psoriasis. A nickel induced psoriatic response strictly limited to the site of contact, with no evidence of the disease elsewhere, is rarely detected in this unit. A preliminary study was therefore undertaken to assess the frequency of concurrent nickel-induced psoriasis, especially in young women.

“Dental amalgam is a major contributor to the daily nonoccupational intake of mercury.  Mercury is ingested and inhaled in connection with placement, removal, and wear of restoration…”

“A thirty-year-old dental surgeon who worked until the 35th week of pregnancy in a surgery in which mercury vapour concentrations in excess of the threshold limit value (TLV) had been detected, gave birth at 42 weeks to a small-for-dates baby with severe brain damage.  The possibility that this baby’s development might have been harmed by mercury is discussed and the literature relevant to teratogenicity of mercury reviewed.  Attention is drawn to the need for further research into the effects on health and pregnancy outcome of mercury vapour in dental surgeries.”