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Arsenic Cycle[edit]

The arsenic (As) cycle covers biogeochemical processes and describes As in terms of reservoirs and fluxes through the atmosphere, lithosphere, pedosphere, hydrosphere, and biosphere. Although arsenic is naturally abundant in the Earth's crust, long-term exposure and high concentrations of arsenic can be detrimental to human health.[1][2]

Arsenic biogeochemical cycle with fluxes in kg/yr and reservoirs in kg. Fluxes are depicted with black arrows, while anthropogenic fluxes are red. Fluxes are between the lithosphere, pedosphere, hydrosphere, and atmosphere.[2]

Arsenic Toxicity[edit]

Arsenic is a metalloid with an atomic number of 33, and its common oxidation states are +3 or +5, as arsenate(III) and arsenite(V).[3] Arsenic is primarily found as organic arsenic compounds, inorganic arsenic compounds, and arsine gas. Arsenic toxicity is dependent on its oxidation state; As(III) is more toxic than As(V) because of its ability to bind to thiol groups on proteins and enzymes, and its slower excretion rate from the body.[4] The World Health Organization recognizes that inorganic arsenic is extremely toxic for human and detrimental to aquatic life.[5]

Anthropogenic Sources and Impacts[edit]

There are a variety of different arsenic sources that have and are still used by humans. Some examples include pesticides, wood preservatives, metal treatment, paint, and coal-based power plants.[2] Anthropogenic residues and discharges by coal-based power plants, mining, and smelting can contaminate rivers, lakes, streams and soil.[1]

References[edit]

  1. ^ a b Masuda, Harue (2018). "Arsenic cycling in the Earth's crust and hydrosphere: interaction between naturally occurring arsenic and human activities". Progress in Earth and Planetary Science. 5 (1): 68. doi:10.1186/s40645-018-0224-3. ISSN 2197-4284.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  2. ^ a b c Matschullat, Jörg (2000). "Arsenic in the geosphere — a review". Science of The Total Environment. 249 (1–3): 297–312. doi:10.1016/S0048-9697(99)00524-0.
  3. ^ Humans., IARC Working Group on the Evaluation of Carcinogenic Risks to (2012). A review of human carcinogens. IARC. ISBN 978-92-832-1320-8. OCLC 869468074.
  4. ^ Michael., Kosnett, (1990). Arsenic toxicity. U.S. Dept. of Health & Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry. OCLC 25527050.{{cite book}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  5. ^ Humans, IARC Working Group on the Evaluation of Carcinogenic Risks to (2012). ARSENIC AND ARSENIC COMPOUNDS. International Agency for Research on Cancer.