Arsenic cycle
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The arsenic (As) cycle is the biogeochemical cycle of natural and anthropogenic exchanges of arsenic with the environment.[1] The cycle is of interest because arsenic is detrimental to human health. The World Health Organization recognizes that inorganic arsenic is extremely toxic for humans (U.S. EPA maximum of 10 ppb in water) and detrimental to aquatic life.[2] Arsenic toxicity can harm nearly every organ system within the human body, as well as causing lung and skin cancer.[3][4][5]
Reservoirs and fluxes
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Arsenic's largest reservoir on Earth is the lithosphere.[5] Earth's crust contains more than 200 mineral types containing As, including many sulfide minerals.[6] Arsenic is found in only a few ore deposits, especially containing arsenopyrite (FeAsS) and tennantite.[7] Sedimentary rocks bearing coal and shale may also contain high As.[8] Major fluxes of As from the lithosphere to the atmosphere are volcanic emissions.[5]
Freshwater and groundwaters commonly contain <1 ppb of As.[5] The concentration of As is pH dependent; acidic conditions mobilize As at pH <5.[5] Oxic seawater contains As(III) as arsenate (average of 1.7 ppb).[9] Major sinks include sedimentation and subduction.[5]
Anthropogenic arsenic sources
[edit]Arsenic is a component of a few man-made materials: pesticides, wood preservatives, metal treatment, paint. It is also emitted from coal-based power plants.[5] Some As is emitted from steel and glass production, and forest and grassland burning.[5]
In the atmosphere, As is mainly present in particulates such as dust, with a residence time of 7 to 10 days.[10][11]
Arsenic toxicity
[edit]The toxicity of As is well known.[12]
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Arsenopyrite (AsFeS) is the most abundant As mineral -
Signs of arsenic poisoning include changes in skin pigmentation. This person experienced As poisoning due to contaminated water.
See also
[edit]References
[edit]- ^ Cullen, William R.; Reimer, Kenneth J. (1989). "Arsenic speciation in the environment". Chemical Reviews. 89 (4): 713–764. doi:10.1021/cr00094a002. hdl:10214/2162.
- ^ Humans, IARC Working Group on the Evaluation of Carcinogenic Risks to (2012). ARSENIC AND ARSENIC COMPOUNDS. International Agency for Research on Cancer.
- ^ "Arsenic Toxicity: What are the Physiologic Effects of Arsenic Exposure? | Environmental Medicine | ATSDR". archive.cdc.gov. 2023-05-25. Retrieved 2026-02-25.
- ^ 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. Bibcode:2018PEPS....5...68M. doi:10.1186/s40645-018-0224-3. ISSN 2197-4284. S2CID 53645300.
- ^ a b c d e f g h i Matschullat, Jörg (2000). "Arsenic in the geosphere — a review". Science of the Total Environment. 249 (1–3): 297–312. Bibcode:2000ScTEn.249..297M. doi:10.1016/S0048-9697(99)00524-0. PMID 10813460.
- ^ Mandal, B (2002-08-16). "Arsenic round the world: a review". Talanta. 58 (1): 201–235. doi:10.1016/s0039-9140(02)00268-0. ISSN 0039-9140.
- ^ WHO Arsenic Compounds, Environmental Health Criteria 224. Geneva: World Health Organization. 2001.
- ^ Smedley, P.L; Kinniburgh, D.G (2002-05-01). "A review of the source, behaviour and distribution of arsenic in natural waters" (PDF). Applied Geochemistry. 17 (5): 517–568. Bibcode:2002ApGC...17..517S. doi:10.1016/S0883-2927(02)00018-5. ISSN 0883-2927. S2CID 55596829.
- ^ Bruland, KW (1983). Trace elements in sea water In Riley JP, Chester R. editors. London: Academic Press. pp. 157–220.
- ^ Chilvers, D; Peterson, P (1987). Global cycling of arsenic. In: Hutchinson TC, Meema KM, editors, Lead, mercury, cadmium and arsenic in the environment. John Wiley & Sons. pp. 279–301.
- ^ Duce, R. A.; Liss, P. S.; Merrill, J. T.; Atlas, E. L.; Buat-Menard, P.; Hicks, B. B.; Miller, J. M.; Prospero, J. M.; Arimoto, R.; Church, T. M.; Ellis, W. (September 1991). "The atmospheric input of trace species to the world ocean" (PDF). Global Biogeochemical Cycles. 5 (3): 193–259. Bibcode:1991GBioC...5..193D. doi:10.1029/91GB01778.
- ^ Michael., Kosnett (1990). Arsenic toxicity. U.S. Dept. of Health & Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry. OCLC 25527050.