Mercury

“An intrauterine growth-retarded (IUGR) model based on restriction of blood supply to the rat fetus at the 17th day of pregnancy was studied. We investigated in vitro the effects of thimerosal and mercuric chloride on Na+K+ATPase activity in total brain homogenate, synaptosomes and myelin at weaning. In addition, we evaluated the reversal effect of serotonin on mercury-inhibited Na+K+ATPase activity. The toxicity, in terms of inhibition of Na+K+ATPase activity was greater with mercuric chloride than with thimerosal. Synaptosomes and principally myelin were more sensitive to the metal salts than total homogenate. Serotonin stimulated the Na+K+ATPase activity in total brain homogenate and synaptosomes but inhibited the enzyme in the myelin fraction. This effect was more marked in the IUGR group than in the control group. Serotonin (1 mM) added to total homogenate pretreated with the mercury salts produced variable reversal effects. In the synaptosomal fraction reverse effect was noted with serotonin. In myelin fraction, added serotonin increased inhibition caused by thimerosal.”

“In middle of Kii peninsula, one of the biggest mercury mine in Japan had been present until about 10 years ago. The mercury contents in water and fish are reported to be higher in this district. So we investigated the mercury in hair of patients and normal controls. In this study the subjects are 23 cases of ALS including 15 cases in Nara and Mie and 8 cases in other prefectures except in Kii peninsula, 14 cases with ataxia, 11 cases with other degenerative diseases like Parkinson’s disease and Alzheimer’s disease, 25 cases of cerebrovascular disease as compared to 26 normal controls. The hair are taken from 3 areas on head of patients and normal controls. They are washed in 2% sodium lauryl sulfate and stirred in distilled water several times, and they are soaked in acetone and dried in filter paper. They are inserted in fire and vaporized mercury are measured (Zeeman Effect Mercury Analyzer) in ppm. The hair mercury concentration is 2.81 ppm in ALS in total, 3.62 ppm in ALS in Nara and Mie and 1.39 ppm in outside of Kii Peninsula, 2.34 ppm in ataxia, 1.83 ppm in other degenerative diseases, 1.66 ppm in cerebrovascular disease and 1.44 ppm in normal controls. Statistically it is significant (p less than 0.05) between that in ALS in Nara and Mie and that in normal controls. 6 cases (40%) with ALS in Nara and Mie have the value above the mean +2 standard deviation of controls…”

“Corrosion attacks on twenty-two dental amalgam restorations after in vivo service have been studied by Scanning Electron Microscopy together with the Energy Dispersive X-Ray Technique, and by optical microscopy. From the measured depth and type of corrosion attack, estimates of released mercury amounts are made. The amalgam fillings have been obtained from members of a group of 250 individuals, who suspected their health troubles potentially to be chronic mercury poisoning from amalgam and were to have all amalgam fillings removed. Three typical patient cases are presented. Model calculations of released mercury, based on previously published measurements of corrosion currents with and without abrasion are also given. The investigations show, that the long-term release of mercury from a few amalgam fillings will often reach or exceed the recommended limits for daily intake of mercury. Hence, mercury from corroding amalgam fillings represents a potential health hazard. Danger of galvanic contact between amalgam and gold restorations is particularly emphasized.”

“Samples, mainly from occipital cortex and pituitary gland, but also from rental cortex, olfactory bulbs, thyroid gland and liver were collected from autopsies of 8 dental staff cases and 27 controls. These samples were analysed for total mercury content using radiochemical neutron activation analyses. The results revealed high mercury concentrations (median 815, range 135-4,040 micrograms Hg/kg wet weight) in pituitaries from the dental staff cases compared to controls (N = 23, median 23 range 6-1, 170 micrograms Hg/kg). In occipital cortex, the cases had a median of 17, range of 4-300 micrograms Hg/kg and the controls (N = 20) had a median of 10, range 2-29 micrograms Hg/kg. A few samples from olfactory bulbs show low mercury concentrations for both cases and controls. Renal cortex was analysed from three cases and contained clearly higher concentrations (945, 1,545, 2,110 micrograms Hg/kg) compared to controls (N = 12, median 180, range 21-810 micrograms Hg/kg). There is no control material for the other analysed samples, but one thyroid sample had an extremely high concentration of 28,000 micrograms Hg/kg.”

“The purpose of this study was to compare the relative cytotoxicity of amalgams and to determine whether their toxicity depends upon composition and aging time, by means of a rapid and sensitive in vitro cell culture test. Zinc-containing amalgams showed higher cytotoxicity than did any other amalgams. High-copper amalgams had the same cytotoxicity as did the low-copper amalgam. The addition of selenium did not reduce the cytotoxicity of amalgam. Moreover, excessive additions of selenium increased the cytotoxicity of amalgam compared with that of a similar selenium-free material. The cytotoxicity of amalgam was decreased with aging time, possibly due to the combined effects of surface oxidation and further amalgamation.”

“Mercury exposure and renal function parameters were examined in 68 dentists and 64 dental assistants. The levels of mercury in urine were low: only three individuals exceeded 20 micrograms/l. Increased excretion of urinary proteins and increased activity of urinary enzymes were observed. This enhanced prevalence of renal function changes appeared not to be related to the mercury urine level, age, sex, or smoking and drinking habits. Only for men was a positive relation between the level of mercury in urine and the activity of beta-galactosidase found. The proteinuria may be due to one or more potential nephrotoxic agents used in dental practice.”

“The concentrations of 17 elements in the hair and nails of 180 Alzheimer’s disease (AD) and control subjects have been determined by instrumental neutron activation analysis (INAA). Comparisons of trace element levels of properly matched AD and control groups revealed significant imbalances in the concentrations of six elements (Br, Ca, Co, Hg, K, and Zn) between disease and control groups. It is noteworthy that each of these has previously been shown by our group, or others, to be altered in some AD brain region(s). Geometric means for each element in both hair and nails of AD and control subjects are presented, and significant differences noted. The significance of these alterations with regard to the possible role of trace elements in the etiology of AD is discussed.”

“Stock’s (1939) findings that amalgam fillings could release mercury vapor created an intense debate. The question was discussed again as a result of Frykholm’s studies in the 1950s (Frykholm, 1957). By using radio-active mercury he showed that insertion of amalgam in humans could give rise to a considerable uptake of mercury as indicated by high concentrations in urine and feces. Dental amalgams once more have become of interest as a source of mercury vapor exposure to the general public (Enwonwu, 1987).”

“In the ANPRM for mercury-containing drug products for OTC topical antimicrobial use (47 FR 436, January 5, 1982), the Advisory Review Panel on OTC Miscellaneous External Drug Products placed all mercury compounds in Category II for topical antimicrobial use. This included the following ingredients: Ammoniated mercury; calomel (mercurous chloride); merbromin (mercurochrome); mercuric chloride (bichloride of mercury, mercury chloride); mercufenol chloride (ortho-chloromercuriphenol, ortho-hydroxyphenylmercuric chloride); mercuric salicylate; mercuric sulfide (red mercuric sulfide); mercuric oxide, yellow; mercury; mercury chloride; mercury oleate; nitromersol; para-chloromercuriphenol; phenylmercuric nitrate; thimerosal; vitromersol; and zyloxin.”

“The cytotoxic action (CTA) of chemical substances contained as admixtures in medical immunobiological preparations on human diploid cells has been studied. Such chemical substances as rivanol and merthiolate in admissible concentrations show the highest degree of CTA. The results obtained in this investigation indicate that different concentrations of chemical substances may produce equal CTA; thus, thiolate in toxic in a dose of 0.8 microgram/ml; the same CTA is produced by aluminium sulfate in a concentration of 500 micrograms/ml. Small doses of chemical substances, producing no explicit manifestations of the cytotoxic effect, may have latent CTA determined by additional methods of investigation. CTA may be manifested as lethal, sublethal and latent cell lesions. In working out regulations on the test for CTA it is expedient to indicate admissible residual amounts of chemical substances contained in finished medical immunobiological preparations, considering that these amounts must be incapable of producing CTA in cell cultures. The conclusion has been made on the expediency of denoting small amounts of chemical substances capable of producing latent CTA as tentatively tolerable doses.”