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Name Description
id 2
T3DB ID T3D0001
Name Arsenic
Class SmallMolecule
Description Arsenic(As) is a ubiquitous metalloid found in several forms in food and the environment, such as the soil, air and water. Physiologically, it exists as an ion in the body. The predominant form is inorganic arsenic in drinking water, which is both highly toxic and carcinogenic and rapidly bioavailable. Arsenic is currently one of the most important environmental global contaminants and toxicants, particularly in the developing countries. For decades, very large populations have been and are currently still exposed to inorganic Arsenic through geogenically contaminated drinking water. An increased incidence of disease mediated by this toxicant is the consequence of long-term exposure. In human's chronic ingestion of inorganic arsenic (> 500 mg/L As) has been associated with cardiovascular, nervous, hepatic and renal diseases and diabetes mellitus as well as cancer of the skin, bladder, lung, liver and prostate. Contrary to the earlier view that methylated compounds are innocuous, the methylated metabolites are now recognized to be both toxic and carcinogenic, possibly due to genotoxicity, inhibition of antioxidative enzyme functions, or other mechanisms. Arsenic inhibits indirectly sulfhydryl containing enzymes and interferes with cellular metabolism. Effects involve such phenomena as cytotoxicity, genotoxicity and inhibition of enzymes with antioxidant function. These are all related to nutritional factors directly or indirectly. Nutritional studies both in experimental and epidemiological studies provide convincing evidence that nutritional intervention, including chemoprevention, offers a pragmatic approach to mitigate the health effects of arsenic exposure, particularly cancer, in the relatively resource-poor developing countries. Nutritional intervention, especially with micronutrients, many of which are antioxidants and share the same pathway with Arsenic , appears a host defence against the health effects of arsenic contamination in developing countries and should be embraced as it is pragmatic and inexpensive. (A7664, A7665).
Categories "Cigarette Toxin", "Pesticide", "Household Toxin", "Pollutant", "Airborne Pollutant", "Food Toxin", "Natural Toxin"
Types "Inorganic Compound", "Metalloid", "Arsenic Compound", "Metal", "Pesticide", "Pollutant", "Food Toxin", "Metabolite", "Cigarette Toxin", "Household Toxin", "Natural Compound"
Synonyms "Arsenic ion", "Arsenic(3+)", "Arsenic(3+) ion", "Arsenic(III)", "Arsenic(III) cation", "As", "As(3+)", "As3+"
CAS Number 7440-38-2
Chemical Formula As
Average Molecular Mass 74.92
Monoisotopic Mass 74.92
IUPAC Name arsenic(3+) ion
Traditional Name arsenic(3+) ion
InChI Identifier InChI=1S/As/q+3
Kingdom Inorganic Compounds
Super Class Homogeneous Metal Compounds
Class Homogeneous Metalloid Compounds
Sub Class
Direct Parent Homogeneous Metalloid Compounds
Alternate Parents "Inorganic Cations"
Geometric Description Acyclic Compounds
Substituents "Inorganic Cation", "Acyclic Compound", "Homogeneous Metalloid"
Descriptors "monoatomic arsenic (ChEBI)"
Status Detected and Quantified
Origin Exogenous
Cellular Locations "Cytoplasm", "Extracellular"
Biofluids "Blood", "Cerebrospinal Fluid (CSF)", "Saliva", "Urine"
State Solid
Appearance Grey metallic solid.
Melting Point > 615°C
Boiling Point 614 °C
Route of Exposure Oral (L2); inhalation (L2); dermal (L2)
Mechanism of Toxicity Arsenic and its metabolites disrupt ATP production through several mechanisms. At the level of the citric acid cycle, arsenic inhibits pyruvate 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. Arsenic's carcinogenicity is influenced by the arsenical binding of tubulin, which results in aneuploidy, polyploidy and mitotic arrests. The binding of other arsenic protein targets may also cause altered DNA repair enzyme activity, altered DNA methylation patterns and cell proliferation. (T1, A17)
Metabolism Arsenic is absorbed mainly by inhalation or ingestion, as to a lesser extent, dermal exposure. It is then distributed throughout the body, where it is reduced into arsenite if necessary, then methylated into monomethylarsenic (MMA) and dimethylarsenic acid (DMA) by arsenite methyltransferase. Arsenic and its metabolites are primarily excreted in the urine. Arsenic is known to induce the metal-binding protein metallothionein, which decreases the toxic effects of arsenic and other metals by binding them and making them biologically inactive, as well as acting as an antioxidant. (L20)
Toxicity LD50: 763 mg/kg (Oral, Rat) (T14) LD50: 13.4 ug/kg (Intraperitoneal, Rat) (T14)
Lethal Dose 130 mg for an adult human. (T15)
Carcinogenicity 1, carcinogenic to humans. (L135)
Uses/Sources Arsenic is used in pesticides, wood preservatives, paints/pigments, and various metal alloys (electronics). Small amounts of arensic can be found in contaminated air, water, and some meat products, especially seafood. (L2)
Minimum Risk Level Acute Oral: 0.005 mg/kg/day (L134) Chronic Oral: 0.0003 mg/kg/day (L134) Chronic Inhalation: 0.01 mg/m3 (L134) The World Health Organization asserts that a level of 0.01 mg/L in drinking water poses a risk of 1/1600 chance of lifetime skin cancer risk.
Health Effects Arsenic poisoning can lead to death from multi-system organ failure, probably from necrotic cell death, not apoptosis. Arsenic is also a known carcinogen, especially in skin, liver, bladder and lung cancers. (T1, L20) Arsenic poisoning is has also been associated with heart disease, (hypertension related cardiovascular), stroke (cerebrovascular diseases), chronic lower respiratory diseases and diabetes. Chronic exposure to arsenic can lead to a vitamin A deficiency which is related to heart disease and night blindness.
Symptoms Exposure to lower levels of arsenic can cause nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and a sensation of “pins and needles” in hands and feet. Breathing high levels of inorganic arsenic can give you a sore throat or irritated lungs. Arsenic also affects the brain, causing neurological disturbances such as headaches, confusion, and drowsiness. (A1)
Treatment Arsenic poisoning can be treated by chelation therapy, using chelating agents such as dimercaprol, EDTA or DMSA. Charcoal tablets may also be used for less severe cases. In addition, maintaining a diet high in sulfur helps eliminate arsenic from the body. (L20)
DrugBank ID
PubChem Compound ID 104734
ChemSpider ID 94549
KEGG Compound ID C06269
UniProt ID 0
ChEBI ID 35828
BioCyc ID CPD-763
CTD ID D001151
Stitch ID Arsenic
ACToR ID 6367
Wikipedia Link http://en.wikipedia.org/wiki/Arsenic
Creation Date 2009-03-06 18:57:53
Update Date 2014-12-24 20:20:50