Heavy metal toxicity vanadium

Sulfur Polymer Cement. SPC has been proven effective in reducing leach rates of reactive heavy metals to the extent that some wastes can be managed solely as low level waste (LLW). When SPC is combined with mercury and lead oxides (both toxic metals), it interacts chemically to form mercury sulfide, HgS, and lead sulfide, PbS, both of which are insoluble in water. A dried sulfur residue from petroleum refining that contained 600-ppm vanadium (a carcinogen) was chemically modified using dicyclopentadiene and oligomer of cyclopentadiene and used to make SC (58). This material was examined by the California Department of Health Services (Cal EPA) and the leachable level of vanadium had been reduced to 8.3 ppm, well below the soluble threshold limit concentration of 24 ppm (59). 

Chromium has proved effective in counteracting the deleterious effects of cadmium in rats and of vanadium in chickens. High mortality rates and testicular atrophy occurred in rats subjected to an intraperitoneal injection of cadmium salts however, pretreatment with chromium ameliorated these effects (Stacey et al. 1983). The Cr-Cd relationship is not simple. In some cases, cadmium is known to suppress adverse effects induced in Chinese hamster (Cricetus spp.) ovary cells by Cr (Shimada et al. 1998). In southwestern Sweden, there was an 80% decline in chromium burdens in liver of the moose (Alces alces) between 1982 and 1992 from 0.21 to 0.07 mg Cr/kg FW (Frank et al. 1994). During this same period in this locale, moose experienced an unknown disease caused by a secondary copper deficiency due to elevated molybdenum levels as well as chromium deficiency and trace element imbalance (Frank et al. 1994). In chickens (Gallus sp.), 10 mg/kg of dietary chromium counteracted adverse effects on albumin metabolism and egg shell quality induced by 10 mg/kg of vanadium salts (Jensen and Maurice 1980). Additional research on the beneficial aspects of chromium in living resources appears warranted, especially where the organism is subjected to complex mixtures containing chromium and other potentially toxic heavy metals. 

Maritidine. It was observed that a variety of alkoxyl or silyloxy phenols 340 (Scheme 51), on oxidation with the non-toxic pheny 1 iodo-tos-trifluoroacetate, instead of customary heavy metal reagents such as trivalent thallium or pentavalent vanadium salts, in the weakly nucleophilic solvent, trifluoroethanol at low temperature, furnished consistently improved yields of cyclisation products 341 [89],... 

The metals of most concern are the heavy metals, especially cadmium, lead, and mercury. Although it is a metalloid with characteristics of both metals and nonmetals, arsenic is commonly classified as a heavy metal for a discussion of its toxicity. Though not particularly toxic, zinc is abundant and may reach toxic levels in some cases. For example, zinc accumulates in sewage sludge and crop productivity has been lowered on land fertilized with sludge because of zinc accumulation. Copper may be toxic to plants. Aluminum, a natural constituent of soil, may be leached from soil by polluted acidic rainwater and reach levels that are toxic to plants. Other metals that may be of concern because of their toxicides include chromium, cobalt, iron, nickel, and vanadium. Radium, a radioactive alpha particle-emitting metal, can be very toxic at even very low levels in water or food. 

Fly ash from municipal waste and industrial waste incinerators contains polychlorinated dibenzo-p-dioxins (PCDDs), including tetrachlorodibenzo-/j-dioxin (TCDD) and polychlorinated dibenzofurans (PCDFs), which are lipophiles, and heavy metals, including chromium, copper, manganese, vanadium, and lead, which are hydrophilesJ29-31 These chemicals have multiple toxicities and are known to impact the human liver, immune system, respiratory system, thyroid, male reproductive function, and CNS J32 34l Several are human carcinogensJ32 35 Enhanced toxic effects are observed in the mixtures of some of theseJ21,22 36 The mixtures of toxicants present in fly ash are complex and the mechanisms for their action on the human body are largely unknown. It is known that occupational exposure to fly... 

Liquid wastes generated by refineries have different chemical compositions including oil and grease, phenols, BTEX, ammonia, suspended solids, cyanide, sulfide, nitrogen compoimds and heavy metals such as iron, cadmium, nickel, chromium, copp>er, molybdenum, selenium, vanadium and zinc. Seeking to evaluate and monitor the environmental imp>act caused by the discharge of effluents in water bodies, toxicity tests are often used as indicators of damage to the aquatic environment. Tests on fish, invertebrates and seaweeds have revealed that most of... 

Heavy Metals - Metallic elements that are located in the transitional series of the periodic chart of elements, These metals are not required in plant nutrition and usually are found in relatively small amounts in nature. Toxicity to plants could result with high concentrations of some heavy metals in soil, and problems in animal and human health may result if heavy metal concentrations in the diet are above certain critical levels. Examples are cadmium (Cd), chromium (Cr),-lead-(Pb),-nickel (Ni), and vanadium (V). Levels of heavy metals may be a problem in some phosphate rock deposits, sewage sludge, animal manures, and some industrial byproducts used as a source of fertilizer. 

A second area of the applicahon of cements for environmental purposes is that of the stabilization/immobilization of Hquid toxic industrial waste, and in parhcu-lar that of hazardous heavy-metal waste streams containing chromium, vanadium, cadmium, and other metals. As noted in Sechon 5.2.4.2, both Cr and V can enter the inter-chain spaces of ettringite to replace groups (Buhlert and Kuzel,... 

A significant health concern with particles, especially those from combustion sources, is their ability to carry toxic metals. Of these, lead is of the greatest concern because it usually comes closest to being at a toxic level. Problems with particulate lead in the atmosphere have been greatly reduced by the elimination of tetraethyl lead as a gasoline additive, an application that used to spew tons of lead into the atmosphere every day. Another heavy metal that causes considerable concern is mercury, which can enter the atmosphere bound to particles or as vapor-phase atomic mercury. Airborne mercury from coal combustion can become a serious water pollution problem, leading to unhealthy accumulations of this toxic element in some fish. Other metals that can cause health problems in particulate matter are beryllium, cadmium, chromium, vanadium, nickel, and arsenic (a metalloid). 

Some of the metals found predominantly as particulate matter in polluted atmospheres are known to be hazardous to human health. All of these except beryllium are so-called heavy metals. Lead is the toxic metal of greatest concern in the urban atmosphere because it comes closest to being present at a toxic level mercury ranks second. Others include beryllium, cadmium, chromium, vanadium, nickel, and arsenic (a metalloid). 

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