It Will Kill Ya Faster Than A Ray Of Light
Arsenopyrite also unofficially called mispickel (FeAsS) is the most common arsenic-bearing mineral. On roasting in air, the arsenic sublimes as arsenic (III) oxide leaving iron oxides.
The most important compounds of arsenic are arsenic (III) oxide, As2O3, ('white arsenic'), the yellow sulfide orpiment (As2S3) and red realgar (As4S4), Paris Green, calcium arsenate, and lead hydrogen arsenate. The latter three have been used as agricultural insecticides and poisons. Orpiment and realgar were formerly used as painting pigments, though they have fallen out of use due to their toxicity and reactivity. Although arsenic is sometimes found native in nature, its main economic source is the mineral arsenopyrite mentioned above; it is also found in arsenides of metals such as silver, cobalt (cobaltite: CoAsS and skutterudite: CoAs3) and nickel, as sulfides, and when oxidised as arsenate minerals such as mimetite, Pb5(AsO4)3Cl and erythrite, Co3(AsO4)2. 8H2O, and more rarely arsenites ('arsenite' = arsenate(III), AsO33- as opposed to arsenate (V), AsO43-). In addition to the inorganic forms mentioned above, arsenic also occurs in various organic forms in the environment. Inorganic arsenic and its compounds, upon entering the food chain, are progressively metabolised to a less toxic form of arsenic through a process of methylation.
Nickernuts are said to contain arsenic. See also Arsenide minerals, Arsenate minerals.
Arsenic and many of its compounds are especially potent poisons. Arsenic disrupts ATP production through several mechanisms including allosteric inhibition of the metabolic enzyme lipothiamide pyrophosphatase during glycolysis. At the level of the citric acid cycle, arsenic inhibits succinate dehydrogenase and by competing with phosphate it uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of NAD+, mitochondrial respiration, and ATP synthesis. Hydrogen peroxide production is also increased, which might form reactive oxygen species and oxidative stress. These metabolic interferences lead to death from multi-system organ failure probably from necrotic cell death, not apoptosis. A post mortem reveals brick red colored mucosa, due to severe hemorrhage. Although arsenic causes toxicity, it can also play a protective role. Elemental arsenic and arsenic compounds are classified as "toxic" and "dangerous for the environment" in the European Union under directive 67/548/EEC.
The IARC recognizes arsenic and arsenic compounds as group 1 carcinogens, and the EU lists arsenic trioxide, arsenic pentoxide and arsenate salts as category 1 carcinogens.
Arsenic is known to cause arsenicosis due to its manifestation in drinking water, “the most common species being arsenate [HAsO42- ; As(V)] and arsenite [H3AsO3 ; As(III)]”. The ability of arsenic to undergo redox conversion between As(III) and As(V) makes its availability in the environment possible. According to Croal, Gralnick, Malasarn, and Newman, “[the] understanding [of] what stimulates As(III) oxidation and/or limits As(V) reduction is relevant for bioremediation of contaminated sites (Croal). The study of chemolithoautotrophic As(III) oxidizers and the heterotrophic As(V) reducers can help the understanding of the oxidation and/or reduction of arsenic.
Arsenic contamination of groundwater has led to a massive epidemic of arsenic poisoning in Bangladesh and neighbouring countries. It is estimated that approximately 57 million people are drinking groundwater with arsenic concentrations elevated above the World Health Organization's standard of 10 parts per billion. The arsenic in the groundwater is of natural origin, and is released from the sediment into the groundwater due to the anoxic conditions of the subsurface. This groundwater began to be used after western NGOs instigated a massive tube well drinking-water program in the late twentieth century. This program was designed to prevent drinking of bacterially-contaminated surface waters, but unfortunately failed to test for arsenic in the groundwater. Many other countries in South East Asia, such as Vietnam, Cambodia, and Tibet, are thought to have geological environments similarly conducive to generation of high-arsenic groundwaters.
The northern United States, including parts of Michigan, Wisconsin, Minnesota and the Dakotas are known to have significant concentrations of arsenic in ground water.
Arsenic can be removed from drinking water through co-precipitation of iron minerals by oxidation and filtering. When this treatment fails to produce acceptable results, adsorptive arsenic removal media may be utilized. Several adsorptive media systems have been approved for point of service use in a study funded by the United States Environmental Protection Agency (U.S.EPA) and the National Science Foundation (NSF).
Magnetic separations of arsenic at very low magnetic field gradients have been demonstrated in point-of-use water purification with high-surface area and monodisperse magnetite (Fe3O4) nanocrystals. Using the high specific surface area of Fe3O4 nanocrystals the mass of waste associated with arsenic removal from water has been dramatically reduced.
The most important compounds of arsenic are arsenic (III) oxide, As2O3, ('white arsenic'), the yellow sulfide orpiment (As2S3) and red realgar (As4S4), Paris Green, calcium arsenate, and lead hydrogen arsenate. The latter three have been used as agricultural insecticides and poisons. Orpiment and realgar were formerly used as painting pigments, though they have fallen out of use due to their toxicity and reactivity. Although arsenic is sometimes found native in nature, its main economic source is the mineral arsenopyrite mentioned above; it is also found in arsenides of metals such as silver, cobalt (cobaltite: CoAsS and skutterudite: CoAs3) and nickel, as sulfides, and when oxidised as arsenate minerals such as mimetite, Pb5(AsO4)3Cl and erythrite, Co3(AsO4)2. 8H2O, and more rarely arsenites ('arsenite' = arsenate(III), AsO33- as opposed to arsenate (V), AsO43-). In addition to the inorganic forms mentioned above, arsenic also occurs in various organic forms in the environment. Inorganic arsenic and its compounds, upon entering the food chain, are progressively metabolised to a less toxic form of arsenic through a process of methylation.
Nickernuts are said to contain arsenic. See also Arsenide minerals, Arsenate minerals.
Arsenic and many of its compounds are especially potent poisons. Arsenic disrupts ATP production through several mechanisms including allosteric inhibition of the metabolic enzyme lipothiamide pyrophosphatase during glycolysis. At the level of the citric acid cycle, arsenic inhibits succinate dehydrogenase and by competing with phosphate it uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of NAD+, mitochondrial respiration, and ATP synthesis. Hydrogen peroxide production is also increased, which might form reactive oxygen species and oxidative stress. These metabolic interferences lead to death from multi-system organ failure probably from necrotic cell death, not apoptosis. A post mortem reveals brick red colored mucosa, due to severe hemorrhage. Although arsenic causes toxicity, it can also play a protective role. Elemental arsenic and arsenic compounds are classified as "toxic" and "dangerous for the environment" in the European Union under directive 67/548/EEC.
The IARC recognizes arsenic and arsenic compounds as group 1 carcinogens, and the EU lists arsenic trioxide, arsenic pentoxide and arsenate salts as category 1 carcinogens.
Arsenic is known to cause arsenicosis due to its manifestation in drinking water, “the most common species being arsenate [HAsO42- ; As(V)] and arsenite [H3AsO3 ; As(III)]”. The ability of arsenic to undergo redox conversion between As(III) and As(V) makes its availability in the environment possible. According to Croal, Gralnick, Malasarn, and Newman, “[the] understanding [of] what stimulates As(III) oxidation and/or limits As(V) reduction is relevant for bioremediation of contaminated sites (Croal). The study of chemolithoautotrophic As(III) oxidizers and the heterotrophic As(V) reducers can help the understanding of the oxidation and/or reduction of arsenic.
Arsenic contamination of groundwater has led to a massive epidemic of arsenic poisoning in Bangladesh and neighbouring countries. It is estimated that approximately 57 million people are drinking groundwater with arsenic concentrations elevated above the World Health Organization's standard of 10 parts per billion. The arsenic in the groundwater is of natural origin, and is released from the sediment into the groundwater due to the anoxic conditions of the subsurface. This groundwater began to be used after western NGOs instigated a massive tube well drinking-water program in the late twentieth century. This program was designed to prevent drinking of bacterially-contaminated surface waters, but unfortunately failed to test for arsenic in the groundwater. Many other countries in South East Asia, such as Vietnam, Cambodia, and Tibet, are thought to have geological environments similarly conducive to generation of high-arsenic groundwaters.
The northern United States, including parts of Michigan, Wisconsin, Minnesota and the Dakotas are known to have significant concentrations of arsenic in ground water.
Arsenic can be removed from drinking water through co-precipitation of iron minerals by oxidation and filtering. When this treatment fails to produce acceptable results, adsorptive arsenic removal media may be utilized. Several adsorptive media systems have been approved for point of service use in a study funded by the United States Environmental Protection Agency (U.S.EPA) and the National Science Foundation (NSF).
Magnetic separations of arsenic at very low magnetic field gradients have been demonstrated in point-of-use water purification with high-surface area and monodisperse magnetite (Fe3O4) nanocrystals. Using the high specific surface area of Fe3O4 nanocrystals the mass of waste associated with arsenic removal from water has been dramatically reduced.