Iodine: Difference between revisions
imported>Howard C. Berkowitz (Some content editing, getting breakdown pathways) |
imported>Howard C. Berkowitz No edit summary |
||
| Line 2: | Line 2: | ||
{{Basic elemental info}} | {{Basic elemental info}} | ||
Iodine is specified as a [[Drug_Enforcement_Administration/Lists|List I chemical]] by the [[United States|US]] [[Drug Enforcement Administration]] and is considered to have high risk of diversion to illicit drug manufacturing.<ref>http://www.deadiversion.usdoj.gov/fed_regs/rules/2007/fr0702.htm</ref> | == Chemical applications == | ||
Iodine is specified as a [[Drug_Enforcement_Administration/Lists|List I chemical]] by the [[United States|US]] [[Drug Enforcement Administration]] and is considered to have high risk of diversion to illicit drug manufacturing.<ref>http://www.deadiversion.usdoj.gov/fed_regs/rules/2007/fr0702.htm</ref> | |||
== Radioactive iodine | Sublimed iodine has been used as a general reagent for developing invisible ink, as it recrystallizes on paper fibers disturbed by the act of writing. For this purpose, however, it has largely been displaced by specialized photographic methods. | ||
== Radioactive iodine== | |||
Several [[isotope]]s of iodine, including <sup>123</sup>I, <sup>124</sup>I, <sup>129</sup>I and <sup>131</sup>I are [[radioactive]] [[isotope]]s of iodine used to treat certain [[cancer]]s or for medical imaging processes <ref>http://www.nejm.org/doi/full/10.1056/NEJMoa041511#t=articleBackground</ref><ref>http://www.medscape.com/viewarticle/477675</ref> and <sup>131</sup> | Several [[isotope]]s of iodine, including <sup>123</sup>I, <sup>124</sup>I, <sup>129</sup>I and <sup>131</sup>I are [[radioactive]] [[isotope]]s of iodine used to treat certain [[cancer]]s or for medical imaging processes <ref>http://www.nejm.org/doi/full/10.1056/NEJMoa041511#t=articleBackground</ref><ref>http://www.medscape.com/viewarticle/477675</ref> and <sup>131</sup> | ||
<sup>131</sup>I has been produced from: <ref>{{citation | Both <sup>129</sup>I and <sup>131</sup>I has been produced from: <ref name=ATSDR-EP>{{citation | ||
| title = Radiation Exposure from Iodine 131: Exposure Pathways | | title = Radiation Exposure from Iodine 131: Exposure Pathways | ||
| url = http://www.atsdr.cdc.gov/csem/iodine/exposure_pathways.html | | url = http://www.atsdr.cdc.gov/csem/iodine/exposure_pathways.html | ||
| publisher = Agency for Toxic Substances and Disease Registry}}</ref> | | publisher = Agency for Toxic Substances and Disease Registry}}</ref> | ||
#[[Nuclear weapon]]s production and atmospheric testing | #[[Nuclear weapon]]s production and atmospheric testing | ||
#Deliberate production for medical use | #Deliberate production for medical use, involving the irradiation of [[tellurium]] | ||
#Nuclear fission in nuclear energy facilities, and released through accidents such as [[Three Mile Island]] | #Nuclear fission in nuclear energy facilities, and released through accidents such as [[Three Mile Island]]. | ||
For reasons of national security, the knowledge of contamination was suppressed in the United States.<ref name=ATSDR-EP/> | |||
===Decay and decay products=== | |||
<sup>131</sup>I has a [[half-life]] of only 8.06 days<ref>http://www.bt.cdc.gov/radiation/isotopes/pdf/iodine.pdf</ref>, so environmental spills are of much less concern that similar spills of other radioactive elements such as [[cesium]] or [[uranium]]. | |||
However, <sup>129</sup>I has a half-life of 15.7 million years.<ref>http://www.epa.gov/radiation/radionuclides/iodine.html#wheredoes</ref> Thus, a spill of <sup>131</sup>I one thousand times the normal background would decay back to normal levels in about 81 days. The <sup>129</sup>I and <sup>131</sup>I atoms emit [[beta particle]]s and emit [[gamma radiation]] during radioactive decay. Because iodine is readily absorbed by the thryroid gland, which uses it to produce [[thyroid hormone]]s, ingestion of radioactive iodine can lead to thyroid pathology, including thyroid cancer. | However, <sup>129</sup>I has a half-life of 15.7 million years.<ref>http://www.epa.gov/radiation/radionuclides/iodine.html#wheredoes</ref> Thus, a spill of <sup>131</sup>I one thousand times the normal background would decay back to normal levels in about 81 days. The <sup>129</sup>I and <sup>131</sup>I atoms emit [[beta particle]]s and emit [[gamma radiation]] during radioactive decay. Because iodine is readily absorbed by the thryroid gland, which uses it to produce [[thyroid hormone]]s, ingestion of radioactive iodine can lead to thyroid pathology, including thyroid cancer. | ||
| Line 21: | Line 25: | ||
== Ingestion == | == Ingestion == | ||
Like [[bromine]], iodine is readily [[sublimation|sublimed]], going from the solid state directly to the gaseous state,(skipping the liquid state) so exposure to the solid form can still lead to inhalation of the chemical. Being a halogen, it also readily forms many salts which are readily soluble, so the molecular form is quickly converted into various salts upon reaction with most environments. Dairy animals exposed to any form of radioactive iodine can thus lead to ingestion by humans. | Like [[bromine]], iodine is readily [[sublimation|sublimed]], going from the solid state directly to the gaseous state,(skipping the liquid state) so exposure to the solid form can still lead to inhalation of the chemical. Being a halogen, it also readily forms many salts which are readily soluble, so the molecular form is quickly converted into various salts upon reaction with most environments. Dairy animals exposed to any form of radioactive iodine can thus lead to ingestion by humans. | ||
===Acute chemical toxicity=== | |||
===Competitive inhibition of radioactive iodine=== | |||
==References== | ==References== | ||
{{reflist|2}} | {{reflist|2}} | ||
Revision as of 19:53, 4 April 2011
Iodine is a chemical element, having the chemical symbol I.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Its atomic number (the number of protons) is 53. It has a Standard Atomic Weight of 126.90447(3), and is typically found as a solid in its elemental form.
Iodine is considered to be a member of the "Halogen" class of elements, has a boiling point of 184.4 °C , and a melting point of 113.7 °C .
Chemical applications
Iodine is specified as a List I chemical by the US Drug Enforcement Administration and is considered to have high risk of diversion to illicit drug manufacturing.[1]
Sublimed iodine has been used as a general reagent for developing invisible ink, as it recrystallizes on paper fibers disturbed by the act of writing. For this purpose, however, it has largely been displaced by specialized photographic methods.
Radioactive iodine
Several isotopes of iodine, including 123I, 124I, 129I and 131I are radioactive isotopes of iodine used to treat certain cancers or for medical imaging processes [2][3] and 131
Both 129I and 131I has been produced from: [4]
- Nuclear weapons production and atmospheric testing
- Deliberate production for medical use, involving the irradiation of tellurium
- Nuclear fission in nuclear energy facilities, and released through accidents such as Three Mile Island.
For reasons of national security, the knowledge of contamination was suppressed in the United States.[4]
Decay and decay products
131I has a half-life of only 8.06 days[5], so environmental spills are of much less concern that similar spills of other radioactive elements such as cesium or uranium.
However, 129I has a half-life of 15.7 million years.[6] Thus, a spill of 131I one thousand times the normal background would decay back to normal levels in about 81 days. The 129I and 131I atoms emit beta particles and emit gamma radiation during radioactive decay. Because iodine is readily absorbed by the thryroid gland, which uses it to produce thyroid hormones, ingestion of radioactive iodine can lead to thyroid pathology, including thyroid cancer.
Ingestion
Like bromine, iodine is readily sublimed, going from the solid state directly to the gaseous state,(skipping the liquid state) so exposure to the solid form can still lead to inhalation of the chemical. Being a halogen, it also readily forms many salts which are readily soluble, so the molecular form is quickly converted into various salts upon reaction with most environments. Dairy animals exposed to any form of radioactive iodine can thus lead to ingestion by humans.
Acute chemical toxicity
Competitive inhibition of radioactive iodine
References
- ↑ http://www.deadiversion.usdoj.gov/fed_regs/rules/2007/fr0702.htm
- ↑ http://www.nejm.org/doi/full/10.1056/NEJMoa041511#t=articleBackground
- ↑ http://www.medscape.com/viewarticle/477675
- ↑ 4.0 4.1 Radiation Exposure from Iodine 131: Exposure Pathways, Agency for Toxic Substances and Disease Registry
- ↑ http://www.bt.cdc.gov/radiation/isotopes/pdf/iodine.pdf
- ↑ http://www.epa.gov/radiation/radionuclides/iodine.html#wheredoes