arsenic [As]
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Introduction
From the Greek arsenikon meaning yellow orniment (a powdered pigment). Arsenic compounds were mined by the ancient Chinese, Greeks & Egyptians. Arsenic was first isolated by Albertus Magnus, a German alchemist in 1250.
Occurrence
- occasionally found as a free element
- mostly found in minerals
Characteristics
- a trivalent & pentavalent solid poisonous element
- either yellow or steel-gray
- crystalline & brittle
- non-metallic
- stable in dry air
- gray form tarnishes & burns in oxygen
- arsenic salts & arsine gases are poisonous
- arsenic is carcinogenic & possibly teratogenic
Uses
- alloys
- semiconductors
- pesticides
- wood preservatives
- glass
- bronzing
Epidemiology
- inorganic arsenic is the carcinogenic form of arsenic
- the FDA has set a limit of 10 parts per billion in for inorganic arsenic in drinking water
- low to moderate arsenic levels in drinking water (<100 ug/L)[6]
- the FDA has proposed the same limit of 10 parts per billion for inorganic arsenic in apple juice[4]
- occasional lots of apple juice may have levels of inorganic arsenic > 10 parts per billion
- in 2012, the FDA tested 94 samples of apple juice
- all contained < 10 parts per billion of inorganic arsenic
- arsenic levels in rice 2.6-7.2 ug/serving safe[5]
- levels in brown rice > white rice
- rice absorbs ~10 times as much arsenic from the environment as other grains do[7]
Pathology
- exposure to even moderate amounts of arsenic (urine arsenic > 15 ug/g of creatinine)is a cardiovascular risk factor[6]
Pharmacokinetics
- arsenic is readily absorbed throught the lungs (in the form of arsine gas) or through the GI tract in the form of arsenic trioxide or organic arsenicals
- absorbtion through the skin occurs slowly
- within 24 hours, arsenic is distributed to all body tissues
- the major route of excretion is through the kidneys
- arsenic crosses the placenta
Laboratory
* rice absorbs ~10 times as much arsenic from the environment as other grains do[7]
More general terms
Additional terms
- arsenic poisoning
- arsenic trioxide; As2O3 (Trisenox)
- As+3 (trivalent arsenic)
- melarsoprol
- tryparsamide
References
- ↑ Webster's Ninth New Collegiate Dictionary, Miriam- Webster Inc. Springfield, MA 1990
- ↑ Chemical & Engineering News, Sept 8, 2003
- ↑ Henry's Clinical Diagnosis & Management by Laboratory Methods, 21st edition, McPherson RA & Pincus MR (es), W.B. Saunders Co., Philadelphia, PA. 2007, pg 322
- ↑ 4.0 4.1 FDA News Release: July 12, 2013 FDA proposes "action level" for arsenic in apple juice. Agency testing and analysis confirm overall safety of apple juice. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm360466.htm
- ↑ 5.0 5.1 FDA Explores Impact of Arsenic in Rice http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm352569.htm
- ↑ 6.0 6.1 6.2 Moon KA et al Association Between Exposure to Low to Moderate Arsenic Levels and Incident Cardiovascular Disease: A Prospective Cohort Study. Ann Intern Med. Published online 24 September 2013 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/24061511 <Internet> http://annals.org/article.aspx?articleid=1740759
- ↑ 7.0 7.1 7.2 7.3 Orciari Herman A. Sofair A, Chavey WE Inorganic Arsenic Still High in Infant Rice Cereals. Physician's First Watch, Dec 8, 2017 David G. Fairchild, MD, MPH, Editor-in-Chief Massachusetts Medical Society http://www.jwatch.org
Arsenic in 9 Brands of Infant Cereal http://www.healthybabycereals.org/sites/default/files/2017-12/HBBF_ArsenicInInfantCerealReport_EnglishSummary.pdf