Mercury Storage Research Articles

Methylmercury chloride and selenomethionine interactions on health and reproduction in mallards

AbstractAdult mallards (Anas platyrhynchos) were fed a control diet or diets containing 10 ppm mercury as methylmercury chloride, 10 ppm selenium as seleno‐DL‐methionine, or 10 ppm mercury plus 10 ppm selenium. One of 12 adult males fed 10 ppm mercury died, and eight others suffered paralysis of the legs by the time the study was terminated. However, when the diet contained 10 ppm selenium in addition to the 10 ppm mercury, none of 12 males became sick. In contrast to the protective effect of selenium against mercury poisoning in males, selenium plus mercury was worse than selenium or mercury alone for some measurements of reproductive success. Both selenium and mercury lowered duckling production through reductions in hatching success and survival of ducklings, but the combination of mercury plus selenium was worse than either mercury or selenium alone. Controls produced an average of 7.6 young per female, females fed 10 ppm selenium produced an average of 2.8 young, females fed 10 ppm mercury produced 1.1 young, and females fed both mercury and selenium produced 0.2 young. Teratogenic effects also were worse for the combined mercury plus selenium treatment; deformities were recorded in 6.1% of the embryos of controls, 16.4% for those fed methylmercury chloride, 36.2% for those fed selenomethionine, and 73.4% for those fed methylmercury chloride and selenomethionine. The presence of methylmercury in the diet greatly enhanced the storage of selenium in tissues. The livers of males fed 10 ppm selenium contained a mean of 9.6 ppm selenium, whereas the livers of males fed 10 ppm selenium plus 10 ppm mercury contained a mean of 114 ppm selenium. However, selenium did not enhance the storage of mercury. The results show that mercury and selenium may be antagonistic to each other for adults and synergistic to young, even within the same experiment.

METHYLMERCURY CHLORIDE AND SELENOMETHIONINE INTERACTIONS ON HEALTH AND REPRODUCTION IN MALLARDS

Adult mallards (Anas platyrhynchos) were fed a control diet or diets containing 10 ppm mercury as methylmercury chloride, 10 ppm selenium as seleno-DL-methionine, or 10 ppm mercury plus 10 ppm selenium. One of 12 adult males fed 10 ppm mercury died, and eight others suffered paralysis of the legs by the time the study was terminated. However, when the diet contained 10 ppm selenium in addition to the 10 ppm mercury, none of 12 males became sick. In contrast to the protective effect of selenium against mercury poisoning in males, selenium plus mercury was worse than selenium or mercury alone for some measurements of reproductive success. Both selenium and mercury lowered duckling production through reductions in hatching success and survival of ducklings, but the combination of mercury plus selenium was worse than either mercury or selenium alone. Controls produced an average of 7.6 young per female, females fed 10 ppm selenium produced an average of 2.8 young, females fed 10 ppm mercury produced 1.1 young, and females fed both mercury and selenium produced 0.2 young. Teratogenic effects also were worse for the combined mercury plus selenium treatment; deformities were recorded in 6.1% of the embryos of controls, 16.4% for those fed methylmercury chloride, 36.2% for those fed selenomethionine, and 73.4% for those fed methylmercury chloride and selenomethionine. The presence of methylmercury in the diet greatly enhanced the storage of selenium in tissues. The livers of males fed 10 ppm selenium contained a mean of 9.6 ppm selenium, whereas the livers of males fed 10 ppm selenium plus 10 ppm mercury contained a mean of 114 ppm selenium. However, selenium did not enhance the storage of mercury. The results show that mercury and selenium may be antagonistic to each other for adults and synergistic to young, even within the same experiment.

Mercury-tainted overbank sediment from past gold mining in north Georgia, USA

Gold was discovered in 1829 and mined until about 1940 in north Georgia, particularly within an area known as the Dahlonega mining district. The mining operations there, which involved mercury amalgamation in stamp mills and sluices, delivered significant quantities of mercury waste to streams. This paper focuses on the downstream dispersal and storage of mercury in streambank sediments of two watersheds near Dahlonega, Georgia. Mercury concentrations for individual samples of historical sediment range from 0.02 to 12.00 ppm, with average values in streambanks near the core of the mining district ranging from 0.2 to 0.6 ppm. Mercury levels rapidly decrease in the downstream direction to concentrations that are slightly above a background level of 0.04±0.02 ppm. Mercury concentrations also appear to decrease with increasing distance from streambanks. Similar levels of mercury contamination from former gold mines probably exist in many other parts of the gold-bearing rocks of the Piedmont of the eastern United States. The bioavailability and environmental hazard posed by the contaminated sediment is not certain.

The future of dental amalgam: a review of the literature. Part 2: Mercury exposure in dental practice.

This is the second article in a series of seven on the future of dental amalgam. It describes the means of exposure to mercury which can occur in dental surgeries from the storage of mercury, preparation and placement of dental amalgam restorations, polishing dental amalgam restorations, the removal of amalgam fillings and the storage of waste amalgam. It also reports on the monitoring of dental practices and studies on the mercury air levels in dental surgeries and blood and urine levels in dentists and their staff. Also, studies which compare these levels with the health and neurobehaviour of dentists and their staff are included. In addition, it discusses post-mortem studies of the mercury levels in body organs in dentists and controls. It then recommends methods for the safe handling of mercury and dental amalgam. Finally, it discusses the issues surrounding the release of mercury into the environment from dental practices and industry.

Intracellular storage of mercury and selenium in different marine vertebrates

Intracellular storage of mercury and selenium in different marine vertebrates

12.2 - Storage and detoxication of anorganic and organic mercury in honeybees: Histochemical and ultrastructural evidence

12.2 - Storage and detoxication of anorganic and organic mercury in honeybees: Histochemical and ultrastructural evidence

Storage and stability of mercury and methylmercury in sea water

The long-term storage behavior of mercury and methylmercury at ng 1 −1 levels in sea water was studied at pH 4.0, 6.0, 8.0 and 10.0, and with 2% (v/v) hydrochloric or nitric acid added. Partial complexation and disappearance of mercury and methylmercury were observed; some of the lost mercury became detectable (by cold-vapour atomic absorption spectrometry) after prolonged storage.

Toxicological effects and storage of cadmium and mercury in an insect Locusta migratoria (Orthoptera)

Toxicity of cadmium and mercury depends on the age and sex of contaminated locust imagoes. Both metals produce fat body injury, consisting in a reduction of energy reserves. They also disturb the function of the female genital apparatus. It is suggested that Hg has a direct effect on the germinal and the somatic cells of the reproductive system, whereas Cd inhibits the differentiation of the fat body cells and therefore the synthesis of the yolk products. No metallothionein has been detected; but Cd induces the production of a Cd-binding glycoprotein with a binding of Cd in the stoichiometric ratio 1 glycoprotein/1 metal. Besides the glycoprotein, mineralized ommochrome granules are important storage sites for Cd.

Polyelectrolyte electrets for electrical energy storage

Membrane electrets composed of mixtures of polyelectrolyte salts and hydrogen bonding materials have been studied to determine their electric charge and electrical energy-storage characteristics. It has been found that membranes containing salts of polystyrenesulfonic acid, plus polyvinyl alcohol, show excellent promise for such electrical storage purposes. The electrets are formed by heating the membrane to above its glass-transition temperature (typically 60–90 °C), placing it in an electric field (in our case, by use of a 22.5 V dry cell battery) and cooling the membrane back to room temperature within the field. It is found that the membrane, typically 0.005–0.010 cm thick, will retain a potential difference of about 2.5 V. These membranes differ from the usual electrets in that they are not really dielectrics. Whereas typical dielectric electrets might have conductivities of the order of 10 14 (Ω-cm) −1, the polyelectrolyte electrets have conductivities of the order of 10 −9 (Ω-cm) −1 or even higher. The charge is stored by orientation of dipoles within divergence elements, probably of a semi-crystalline nature, scattered throughout the membrane. The charge storage is stable and, if the membrane is stored with the faces shorted, will last indefinitely. The electret can be discharged by connecting the two faces to an external circuit and heating the membrane to above the charging temperature. Alternatively, electrets can be discharged by use of ultraviolet light, though we have not attempted this method as yet. Using thermal discharge, we have measured charge storage capacities of the order of 1 C/g. Using our present system, we foresee no difficulty in increasing charge storage capacity by an order of magnitude or more, thus making the system comparable to lead-acid or mercury storage batteries.

Storage of mercury at submolar concentrations.

Storage of mercury at submolar concentrations.

THE ABSORPTION OF ORGANOMERCURIAL COMPOUNDS FROM THE VAGINAL ROUTE OF THE RABBITS. II. DISTRIBUTION AND EXCRETION OF OMEGA-ETHYLMERCURITHIO-N-UNCECANOIC ACID AND PHENYLMERCURIC ACETATE.

The excretion and tissue distribution of ω-ethylmercuri (Hg203)-thio-n-undecanoic acid (EMU) after vaginal administration were pursued in comparison with phenylmercuric (Hg203)-acetate (PMA). PMA was excreted into feces and urine twice as much as EMU when a Carbowax 2000 suppository was employed. The excretion of EMU was almost equal irrespective of the use of Carbowax 2000 or Rx 6 (emulsion vehicle containing stearic acid). A decrease in total excretion of PMA by the use of the emulsion vehicle was observed over a Carbowax 2000 vehicle. The decrease would indicate a decrease in absorption due to a change of PMA into more lipophilic stearate. Cumulative excretion of PMA after repeated daily administrations showed a linear relationship, but in the case of EMU, a more increase of excretion was observed, showing a correspondence with the accumulation in tissue. Both PMA and EMU showed a high mercury storage in the liver and kidneys. A comparative study was made of the amounts and rates of mercurials excreted following a single intravenous administration. The excretion of mercurial into the urine following intravenous administration of the mercurials was higher or not less than vaginal application. Acceleration of mercurial excretion was observed when BAL or α-lipoic acid was given simultaneously with insertion of a suppository containing mercurials.

Storage of dental alloy and mercury together before trituration

Storage of dental alloy and mercury together before trituration

Mercury and lead storage in human tissues; with special reference to thrombocytopenic purpura.

Mercury and lead storage in human tissues; with special reference to thrombocytopenic purpura.

Biologic Assay of Mercury Ointments

Using the storage of mercury in the kidney of the rat as a measure of cutaneous penetration, 8 official mercury ointments have been assayed. Mercury oleate and nitrate ointments showed the greatest penetration; calomel and yellow mercuric oxide showed the least. Intermediate in penetration were mercurial, ammoniated and red oxide of mercury ointments. The degree of penetration of mercury was relatively insensitive to large differences in concentration of mercury in the ointments.