Arsenic Speciation and Toxicity in Biological Systems

A review on completing arsenic biogeochemical cycle: Microbial volatilization of arsines in environment

“…Inorganic As can be chemically or biologically methylated into mono-, di-or trimethylarsine. In vivo, the toxicity of soluble inorganic and organic As species are dimethylarsenite (DMAs(III)), monomethylarsenite (MMAs(III)) > As(III) > As(V) > dimethylarsenate, (DMAs(V)), monomethylarsenate (MMAs(V)) > trimethylarsine (TMAs), trimethylarsine oxide (TMAsO) (Akter et al, 2005). Inorganic arsine and mono-, di-, and trimethylarsine, denoted as AsH 3 , MeAsH 2 ((CH 3 )AsH 2 ), Me 2 AsH ((CH 3 ) 2 AsH) and Me 3 As ((CH 3 ) 3 As), termed collectively arsines, are a volatile class of trivalent arsenic compounds and can partition into the atmosphere from aqueous solution due to their low boiling points (Mestrot et al, 2013), as illustrated in Fig.…”

Immunotoxic and Genotoxic Effects of Arsenic and Ameliorative Potential of Quercetin and Probiotics in Wistar Rat

“…Because of the extensive presence of As in the environment and its toxic properties, it is considered a hazardous environmental toxicant [16]. However, further studies are needed to reveal the potential roles and effectiveness of mitigating agents against its toxicity.…”

Fungal Bioweathering of Mimetite and a General Geomycological Model for Lead Apatite Mineral Biotransformations

“…The spread and ubiquity of As in the environment, its biological toxicity, and its enhanced redistribution due to anthropogenic activities are causes of major public concern (14-16, 18, 19). Anthropogenic arsenic sources include the use of agricultural pesticides, wood preservatives, and medicines, oil and coal burning for energy production, waste incineration and disposal, and industrial activities associated with metal acquisition and processing from mineral ores (18,19).More than 300 arsenic minerals occur in nature, and of these, ϳ60% occur as arsenates, 20% as sulfides and sulfosalts, 10% as oxides, and the rest as arsenites, arsenides, the native element, and metal alloys (14,16,(18)(19)(20). In primary arsenic-bearing minerals, arsenic is present as the anion arsenide (As 3Ϫ ) or diarsenide (As 2 6Ϫ ) or as sulfarsenide (AsS 3Ϫ ) in sulfidic ores in the form of arsenides of Fe, Cu, Co, and Ni (15,20).…”

“…Arsenic is widely distributed in the Earth's crust, with an average concentration of 2 to 5 mg kg Ϫ1 , and is associated primarily with igneous and sedimentary rocks in the form of inorganic arsenic compounds (14)(15)(16)(17). Arsenic therefore naturally occurs in trace quantities in the lithosphere, hydrosphere, and atmosphere and in all living organisms, where it can be acutely toxic because of its similarity to inorganic phosphate and its affinity for protein thiols (14-16, 18, 19).…”

“…Arsenic therefore naturally occurs in trace quantities in the lithosphere, hydrosphere, and atmosphere and in all living organisms, where it can be acutely toxic because of its similarity to inorganic phosphate and its affinity for protein thiols (14-16, 18, 19). Arsenate (AsO 4 3Ϫ ) is an analogue of essential phosphate (PO 4 3Ϫ ) and can be taken up via phosphate transport systems in most organisms, and it may replace phosphate in several energy transfer phosphorylation reactions (14)(15)(16). Arsenite (AsO 3 3Ϫ ) has a high affinity for protein thiol groups and can therefore inactivate many enzymes (14)(15)(16).…”