Metal toxicity mercury

Many studies have reported the effects of metals on general soil microbiological processes. Metals including cadmium, chromium, copper, lead, mercury, nickel, and zinc have been reported to inhibit many of the microbial processes listed above. Metal toxicity in the environment ultimately decreases litter decomposition, which can be measured by the rate of mass loss. Both copper (0.5 mg Cu g4 soil) and zinc (1.0 mg Zn g 1 soil) were shown to decrease the rate of decomposition of unpolluted Scots pine needle litter near a brass mill in Sweden.61 Duarte et al.63 also determined that copper and zinc toxicity reduced leaf decomposition rates and fungal reproduction. Other metals, such as cadmium, nickel, and lead, have also been reported to decrease litter decomposition.77... 

Devi, V.U. 1987. Heavy metal toxicity to fiddler crabs, Uca annulipes LatreiUe and Uca triangularis (Milne Edwards) tolerance to copper, mercury, cadmium, and zinc. Bull. Environ. Contam. Toxicol. 39 1020-1027. Devi, V.U. and Y.R Rao. 1989. Heavy metal toxicity to fiddler crabs, Uca annulipes Latreille and Uca triangularis (Milne Edwards) respiration on exposure to copper, mercury, cadmium, and zinc. Bull. 

A common type of button battery, shown here, contains silver oxide or mercury(ll) oxide. Mercury is cheaper than silver, but discarded mercury batteries release toxic mercury metal into the environment. 

An additional environmental factor that may affect metal contaminant transformation in the subsurface is the air-water ratio. A toxic metal like mercury does not remain in a metallic form in an anaerobic environment. Microorganisms transform metallic mercury to methytmercury (CHj-Hg ") and dimethylmercury (CHj-Hg-CH3), which are volatile and absorbable by the organic fraction of the subsurface solid phase or subsurface microorganisms. 

The principles of toxicology, dose - response and individual sensitivity, are well illustrated by the metals. Historically, most of the interest and concern was with the obvious effects of metal toxicity such as colic from lead or symptoms of the Mad Hatter from mercury. The emphasis has changed to the more subtle and long-term effects and concern for potentially sensitive individuals. It is now well documented that children exposed to even low levels of lead will have a lowered IQ and other learning difficulties. This knowledge has resulted in significant changes in our use of metals. 

Mercury is quickly limited at positive potentials (+0.25 V with respect to SCE). Beyond this potential, anodic dissolution of mercury occurs. However, mercury can be used at up to —1.8 or —2.3 V depending on whether the supporting electrolyte is acidic or alkaline. This range offers several possibilities, especially for the determination of heavy metals. The mercury used must be extremely pure (six-time distilled, under nitrogen). Unfortunately, the use of mercury as an electrode is a disadvantage because of its toxicity the mercury must be recycled after each use. 

Spark source (SSMS) and thermal emission (TEMS) mass spectrometry are used to determine ppb to ppm quantities of elements in energy sources such as coal, fuel oil, and gasoline. Toxic metals—cadmium, mercury, lead, and zinc— may be determined by SSMS with an estimated precision of 5%, and metals which ionize thermally may be determined by TEMS with an estimated precision of 1% using the isotope dilution technique. An environmental study of the trace element balance from a coal-fired steam plant was done by SSMS using isotope dilution to determine the toxic metals and a general scan technique for 15 other elements using chemically determined iron as an internal standard. In addition, isotope dilution procedures for the analysis of lead in gasoline and uranium in coal and fly ash by TEMS are presented. 

Kidney. Because the kidney is the main excretory organ of the body, it is a common target organ for metal toxicity. Cadmium and mercury, in particular, are potent nephro-toxicants and are discussed more fully in the following sections and in Chapter 15. 

However, organic pollutants are often accompanied by heavy metal ion contaminants that can be reduced by photogenerated electrons into their less toxic, nonsoluble metallic form. Ti02-assisted photoreductive catalysis was found to be useful in the removal of certain heavy metals including mercury, silver, platinum, palladium, rhodium, and gold via their reduction followed by deposition at the catalyst surface [20-22] or photoreduction of nitroaromatic compounds [23-26]. The use of photogenerated electrons for deposition of metal layers on... 

To clean a metal diffusion pump, it must be removed from the rest of the system. Pour the used oil (or mercury) into a proper receptacle. Do not throw the mercury away because it is a toxic waste (a heavy metal). Fortunately, mercury may be reclaimed and reused. As far as diffusion pump oils, check with the health and safety and/or environmental officer in your institution and/or the waste disposal management of your city. Be sure to mention any hazardous materials that may have been absorbed by the pump oil during its operation to the proper authorities. 

It is well known that a large number of chemical substances, including toxic metals and metalloids such as arsenic, cadmium, lead, and mercury, cause cell injury in the kidney. With metal-induced neurotoxicity, factors such as metal-binding proteins, inclusion bodies, and cell-specific receptor-like proteins seem to influence renal injury in animals and humans. It is of interest to note that certain renal cell populations become the targets for metal toxicity, while others do not. In fact, the target cell populations handle the organic and common inorganic nephrotoxicants differently. ... 

A few metals, such as lead and mercury, can cross the placental barrier. The very young population and the older population are most susceptible to metal toxicity. 

To protect your children from metallic mercury, teach them not to play with shiny, silver liquids. Schoolteachers (particularly science teachers) and school staff need to know about students fascination with metallic mercury. Teachers and school staff should teach children about the dangers of getting sick from playing with mercury, and they should keep metallic mercury in a safe and secured area (such as a closed container in a locked storage room) so that children do not have access to it without the supervision of a teacher. Metallic mercury evaporates slowly, and if it is not stored in a closed container, children may breathe toxic mercury vapors. 

Metallic mercury vapors are very toxic and are virtually odorless. Inhalation of mercury-laden dust, vapor, or mist should be avoided. Metallic mercury not should not come in contact with eyes, skin, or clothing. If children are exposed directly to metallic mercury, the contaminated body area should be thoroughly washed, and contaminated clothing should be removed and disposed of in a sealed plastic bag (ATSDR 1997). ATSDR and EPA recommend very strongly against the use of any uncontained metallic (liquid) mercury in homes, automobiles, day care centers, schools, offices, and other public buildings. If a child has metallic mercury on his or her clothing, skin, or hair, the fire department should be advised and the child should be properly decontaminated (ATSDR 1997). 

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