Metal toxicity nickel

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... 

Coprecipitation is a partitioning process whereby toxic heavy metals precipitate from the aqueous phase even if the equilibrium solubility has not been exceeded. This process occurs when heavy metals are incorporated into the structure of silicon, aluminum, and iron oxides when these latter compounds precipitate out of solution. Iron hydroxide collects more toxic heavy metals (chromium, nickel, arsenic, selenium, cadmium, and thorium) during precipitation than aluminum hydroxide.38 Coprecipitation is considered to effectively remove trace amounts of lead and chromium from solution in injected wastes at New Johnsonville, Tennessee.39 Coprecipitation with carbonate minerals may be an important mechanism for dealing with cobalt, lead, zinc, and cadmium. 

Cadmium (Cd) anode cells are at present manufactured based on nickel-cadmium, silver-cadmium, and mercury-cadmium couples. Thus wastewater streams from cadmium-based battery industries carry toxic metals cadmium, nickel, silver, and mercury, of which Cd is regarded the most hazardous. It is estimated that globally, manufacturing activities add about 3-10 times more Cd to the atmosphere than from natural resources such as forest fire and volcanic emissions. As a matter of fact, some studies have shown that NiCd batteries contribute almost 80% of cadmium to the environment,4,23 while the atmosphere is contaminated when cadmium is smelted and released as vapor into the atmosphere4 Consequently, terrestrial, aquatic, and atmospheric environments become contaminated with cadmium and remain reservoirs for human cadmium poisoning. 

The most commonly observed toxic reaction to nickel and nickel compounds in the general human population is nickel dermatitis and skin sensitivity arising from dermal contact with metals containing nickel (Sunderman 1970 NAS 1975 Norseth and Piscator 1979 USEPA 1980, 1986 WHO 1991 USPHS 1993). Studies on occupational dermatitis, which is the most prevalent... 

Heavy metal toxicity in plants is infrequent (143). In many cases, metal concentrations in plant parts show poor correlation with soil concentrations of the element (147). Plants tend to exclude certain elements and readily accept or concentrate others. Lisk (148) reported natural plant soil concentration ratios of 0.05 or less for As, Be, Cr, Ga, Hg, Ni, and V. Cadmium appears to be actively concentrated and selenium appears to be easily exchangeable. Indicator plants are capable of markedly concentrating specific elements, e.g., Astragalus spp. for selenium (138) and Hybanthus floribundus for nickel (149). Plants growing on mine wastes have been shown to evolve populations which exhibit metal-specific tolerances (150). 

The other major toxic effect of nickel is nickel dermatitis, an allergic contact dermatitis arising from contact with nickel metal. About 5 to 10% of people are susceptible to this disorder. It almost always occurs as the result of wearing nickel jewelry in contact with skin. Nickel carbonyl, Ni(CO)4, is an extremely toxic nickel compound discussed further in Chapter 12. 

Leachates from ISW and municipal solid waste (MSW) sites contain complex mixtures of toxic chemicals. These include heavy metals (iron, nickel, zinc, manganese, chromium, cadmium, and lead) as well as numerous organic compounds (including aliphatic and aromatic hydrocarbons, PAHs, alcohols, esters, aldehydes, and pesticides). Specific compositions of leachates vary with pH, soil type, and specific chemicals contained in the sites. All ISW and MSW sites, however, leach toxic mixtures of chemicals. 

The leachabilities of toxic hazardous material were determined using the EPA extraction procedures (J). The leachabilities of certain metals (copper, nickel, potassium, and sodium) that are not considered toxic were also determined. Samples were stirred 24 h in water and filtered then the water-soluble concentrations were determined by atomic absorption. These metals form highly soluble sulfates that would be very susceptible to leaching and provide a test of the degree of ease of leaching within the phosphogypsum stacks. 

Some of these helper proteins such as UreE and HybB bind the nickel cations meant for incorporation into nickel-containing enzymes (Lee et al. 1993, Park et al. 1994, Lee etal., 2002b, Song etal. 2001, Remaut etal. 2001). These proteins act as metal chaperones, which discriminate between anabolic nickel that serves as a trace element and toxic nickel. Ni(II) binds to polyphosphate, like many other divalent cations (Gonzalez and Jensen 1998), but... 

The metal hydride-nickel cell, MH c/KOH/NiOOH, also makes use of the NiOOH cathode it replaces the Cd anode with a metal hydride, MH insertion alloy having its Fermi energy like that of Cd, well-matched to the LUMO of the aqueous KOH electrolyte. However, the H -ion diffusivity in the hydride is slower than that in the gelatinous Cd(OH)2, so it has a poorer rate capability at lower temperatures. On the other hand, it eliminates the heavy, toxic Cd to give a higher energy density (Wh/kg) and provides a safe power source for electric vehicles. However, a Zn/KOH/NiOOH cell of good cycle life may prove competitive. 

Metal Toxicity Inhibition of microbial activity by certain metals— including arsenic, barium, cadmium, chromium, lead, mercury, and nickel—that interact with cellular proteins in complex ways. Microclimate Small but distinct climate zone within a larger climate area slight differences in landscape climates (frequently due to shade trees or mountains and valleys) allow for variegated and unusual species to occupy a common terrain. Micrometeorology Study of the atmosphere just above the ground. 

Burd, G. T, Dixon, D. G., Ghck, B. R. Plant growth promoting that decrease heavy metal toxicity in plants. Canadian Journal of Microbiology. 2000, V. 46,247-255. Siunova, T. V., Kochetkov, V. V., Boronin, A. M. Effect of ihizosphere bacteria on nickel accumulation by barley plants. Agrochemicals. 2006, K 10,80-84. Mannanov, R. N., Saharova, R. K. Antibiotics produced by Bacillus bacteria. Chemistry of Natural Compounds. 2001, V. 37. J4 2,117-123. 

---