Elemental mercury toxicity

Mercer JJ, Bercovitch L, Muglia JJ. Acrodynia and hypertension in a young girl secondary to elemental mercury toxicity acquired in the home. Pediatr Dermatol 2012 29(2) 199-201. 

Some elements found in body tissues have no apparent physiological role, but have not been shown to be toxic. Examples are mbidium, strontium, titanium, niobium, germanium, and lanthanum. Other elements are toxic when found in greater than trace amounts, and sometimes in trace amounts. These latter elements include arsenic, mercury, lead, cadmium, silver, zirconium, beryUium, and thallium. Numerous other elements are used in medicine in nonnutrient roles. These include lithium, bismuth, antimony, bromine, platinum, and gold (Eig. 1). The interactions of mineral nutrients with... 

Some metals can be converted to a less toxic form through enzyme detoxification. The most well-described example of this mechanism is the mercury resistance system, which occurs in S. aureus,43 Bacillus sp.,44 E. coli,45 Streptomyces lividans,46 and Thiobacillus ferrooxidans 47 The mer operon in these bacteria includes two different metal resistance mechanisms.48 MerA employs an enzyme detoxification approach as it encodes a mercury reductase, which converts the divalent mercury cation into elemental mercury 49 Elemental mercury is more stable and less toxic than the divalent cation. Other genes in the operon encode membrane proteins that are involved in the active transport of elemental mercury out of the cell.50 52... 

Inorganic elements can be broadly classified as metals and nonmetals. Most metallic elements become toxic at some concentration. Nine elements (arsenic, barium, cadmium, chromium, lead, mercury, nickel, selenium, and thallium) and cyanide are defined as hazardous inorganics for the purposes of deep-well injection. 

With respect to Cr a distinction should be made between Cr(III), which is the common oxidation state in the soils, being rather immobile and so toxic, and Cr(VI), which is very mobile and very toxic. With respect to Hg, the situation is even more complex, due to the occurrence of mercuric mercury (Hg2+), mercurous mercury (Hg2+), elemental mercury (Hg°) and organic mercury species, such as methyl mercury, (CH3)2Hg (see Section 18.5). Furthermore, volatilization of elemental mercury and organic mercury species is common. A description of these... 

Antimony was known in the days of alchemy (500 BCE to 1600 ce) when it was associated with other metals and minerals such as arsenic, sulfides, and lead used as medications. It is possible that an alchemist, Basilus Valentinus (fi. 1450), knew about antimony and some of its minerals and compounds sometime around the mid-fifteenth century ce. Physicians of this period—and earlier periods—used elements such as mercury and antimony to cure diseases, although they knew that these elements were toxic in larger doses. Antimony was used to treat depression, as a laxative, and as an emetic for over two thousand years. Despite the elements poisonous nature, physicians of that early era considered both mercury and antimony good medicines. 

Mercury dimethyl is a toxic environmental pollutant. It is found in polluted bottom sediments and in the bodies of fishes and birds. In the bodies of fishes and birds it occurs along with monomethyl mercury. The latter, as CH3Hg+ ion, is formed by microorganism-induced biological methylation of elemental mercury or agricultural fungicide mercury compounds that are discharged into the environment. 

C. The symptoms are characteristic of a person chronically exposed to vapors released from elemental mercury. Since the dental technician may handle elemental mercury, including mishandling, the symptoms presented may occur. While the technician may be exposed to solvent vapors released from dental adhesives, the symptoms are not characteristic of this type of exposure. Fluoride toxicity would not be expected because these are not symptoms associated with fluoride ingestion, and the patient and not the technician would be most likely exposed to quantities high enough to cause any symptoms. The technician has little exposure to li-docaine, and the symptoms are not typical of lido-caine toxicity. 

Heat Transfer The movement and dispersion of heat by conduction, convection, or radiation. Heavy Metals High-density metallic elements generally toxic to plant and animal life in low concentrations (e.g. mercury, chromium, cadmium, arsenic, and lead). 

Elemental Mercury Vapor. Although there may be toxic effects to the respiratory system from the inhalation of mercury vapor, the major toxic effect is to the CNS. This is especially true after chronic exposure. There are a variety of symptoms such as muscle tremors, personality changes, delirium, hallucination, and gingivitis. 

Mercury exists in three forms elemental, inorganic, and organic with different toxic effects. Elemental mercury is absorbed as a vapor and may enter the CNS and cause toxicity there. Inorganic mercury is poorly absorbed, but the cysteine conjugate of mercury is concentrated in the kidney by active transport. The kidney is the main target organ (also gastrointestinal tract if exposure by that route). 

Clearly the oil is a much cleaner fuel than the original coal, from the point of view either of the environmentalist or of the plant engineer concerned with fouling of steam and superheater tubes. The sulfur contents of the oils are 0.1-0.2%, which is acceptable, but the nitrogen contents are about 0.6%, which may cause undesired NOx emissions. Some of the more toxic elements, (mercury, selenium, fluorine, and cadmium) have not yet been determined in oil. It is not clear what will be done with the solid residue whether it will be disposed of as waste or whether its small carbon content, typically 20-50% depending on the... 

Another flavoprotein constructed on the glutathione reductase pattern is the bacterial plasmid-encoded mercuric reductase which reduces the highly toxic Hg2+ to volatile elemental mercury, Hg°. A reducible... 

Mercury may be present in air in different chemical states such as the elemental form (as a vapour or adsorbed on particular matter) or in the form of volatile mercury compounds (mercury chloride, methyl-mercuric chloride, and dimethyl mercury). Although elemental mercury is only one of the mercury forms which is not as toxic as its organic or ionic forms, analytical determination of elemental mercury is of special importance. Such analysis is used not only for determination of elemental mercury in environment, but also as a method for determination of other forms of mercury after reductive treatment. 

Literally hundreds of complex equilibria like this can be combined to model what happens to metals in aqueous systems. Numerous speciation models exist for this application that include all of the necessary equilibrium constants. Several of these models include surface complexation reactions that take place at the particle-water interface. Unlike the partitioning of hydrophobic organic contaminants into organic carbon, metals actually form ionic and covalent bonds with surface ligands such as sulfhydryl groups on metal sulfides and oxide groups on the hydrous oxides of manganese and iron. Metals also can be biotransformed to more toxic species (e.g., conversion of elemental mercury to methyl-mercury by anaerobic bacteria), less toxic species (oxidation of tributyl tin to elemental tin), or temporarily immobilized (e.g., via microbial reduction of sulfate to sulfide, which then precipitates as an insoluble metal sulfide mineral). 

The answer is very likely, and pigments are a possible explanation of the way artists were prone to abnormal moodiness and poor health. As we have seen, many pigments were compounds of the toxic elements, mercury, lead, and arsenic. As long ago as 1713, the physician Bernardino Ramazzini speculated that both Correggio and Raphael had been victims of lead poisoning. 

Mercury contaminated foodstuffs and water supplies are a concern because of the extreme toxicity of the element and its compounds. Elemental mercury is used in the production of chlorine gas, and organomercury compounds formerly found use as pesticides and fungicides. Alkyl mercury compounds are of greatest concern since they do not degrade readily, and methyl mercury compounds concentrate in fish lipid tissue [9]. Pregnant women are at greatest risk since methyl mercury readily crosses the placenta, affecting the fetus [6]. 

Mercury. Mercury Is a classic heavy metal occupational toxicant studied by Paracelsus and popularized in Lewis Carol s Alice in Wonderland. Both elemental and organomercury compounds are of great interest to Industrial hygienists. Elemental mercury is still routinely determined from acidic KMnO collection by dithizone complexation at 515 nm (6) (Table VI ). Surprisingly, Hg is not Included In P CAM 173. Elemental mercury has been determined by flameless AAS (P CAM 165) for urine,... 

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