Kepone

This article is about the pesticide. For the indie rock band, see Kepone (band).
Kepone
Names
IUPAC name
decachloropentacyclo[5.3.0.02.6.03.9.04.8]decan-5-one[1]
Other names
Chlordecone
Clordecone
Merex
CAS name: 1,1a,3,3a,4,5,5,5a,5b,6-decachlorooctahydro-1,3,4-metheno-2H-cyclobuta[cd]pentalen-2-one
Identifiers
143-50-0 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:16548 N
ChEMBL ChEMBL462576 YesY
ChemSpider 293 YesY
ECHA InfoCard 100.005.093
EC Number 205-601-3
KEGG C01792 YesY
PubChem 299
UNII RG5XJ88UDF N
Properties
C10Cl10O
Molar mass 490.633 g/mol
Appearance tan to white crystalline solid
Odor odorless
Density 1.6 g/cm3
Melting point 349 °C (660 °F; 622 K) (decomposes)
0.27 g/100 mL
Solubility soluble in acetone, ketone, acetic acid
slightly soluble in benzene, hexane
log P 5.41
Vapor pressure 3.10−7 kPa
Thermochemistry
764 J/K mol
-225.9 kJ/mol
Hazards
Main hazards carcinogen[2]
Flash point Non-flammable[2]
Lethal dose or concentration (LD, LC):
95 mg/kg (rat, oral)
US health exposure limits (NIOSH):
PEL (Permissible)
 none[2]
REL (Recommended)
 Ca TWA 0.001 mg/m3[2]
IDLH (Immediate danger)
 N.D.[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Kepone, also known as chlordecone, is an organochlorine compound and a colourless solid. This compound is a controversial insecticide related to Mirex and DDT. Its use was so disastrous that it is now prohibited in the western world, but only after many millions of kilograms had been produced.[3] Kepone is a known persistent organic pollutants (POP), classified among the "dirty dozen" and banned globally by the Stockholm Convention on Persistent Organic Pollutants as of 2011.

Toxicology

The LC50 (LC = lethal concentration) is 35 μg/ L for Etroplus maculatus,[4] 0.022–0.095 mg/kg for blue gill and trout. Kepone bioaccumulates in animals by factors up to a million-fold. Workers with repeated exposure suffer severe convulsions resulting from degradation of the synaptic junctions.[3]

Kepone has been found to act as an agonist of the GPER (GPR30).[5]

History

In the US, kepone was produced by Allied Signal Company and LifeSciences Product Company in Hopewell, Virginia. The improper handling and dumping of the substance into the nearby James River (U.S.) in the 1960s and 1970s drew national attention to its toxic effects on humans and wildlife. The product is similar to DDT and is a degradation product of Mirex.[3] The history of Kepone incidents are reviewed in Who's Poisoning America?: Corporate Polluters and Their Victims in the Chemical Age (1982). In 2009, Kepone was included in the Stockholm Convention on persistent organic pollutants, which bans its production and use worldwide.[6]

Case studies

James River estuary

Due to the pollution risks, many businesses and restaurants along the river suffered economic losses. In 1975 Governor Mills Godwin Jr. shut down the James River to fishing for 100 miles, from Richmond to the Chesapeake Bay. This ban remained in effect for 13 years, until efforts to clean up the river began to get results.[7]

French Antilles

The French island of Martinique is heavily contaminated with kepone,[8] following years of its unrestricted use on banana plantations.[9][10] Despite a 1990 ban of the substance by France, the economically powerful planter community lobbied intensively to gain the power to continue using kepone until 1993. They had argued that no alternative pesticide was available, which has since been disputed. Similarly, the nearby island of Guadeloupe is also contaminated, but to a lesser extent. Since 2003, local authorities have restricted cultivation of crops because the soil has been seriously contaminated by kepone. Martinique and Guadeloupe have some of the highest prostate cancer diagnosis rates in the world.[11]

Synthesis

Kepone is made by dimerizing hexachlorocyclopentadiene and hydrolyzing to a ketone.[12]

References

  1. ↑ IUPAC Agrochemical information.
  2. 1 2 3 4 5 "NIOSH Pocket Guide to Chemical Hazards #0365". National Institute for Occupational Safety and Health (NIOSH).
  3. 1 2 3 Robert L. Metcalf "Insect Control" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Wienheim, 2002. doi:10.1002/14356007.a14_263
  4. ↑ Asifa KP, Chitra KC. (2015). Determination of Median Lethal Concentration (LC50) and Behavioral Effects of Chlordecone in the Cichlid fish, Etroplus maculatus. Int J. Sci.Res.4 (3):1473-75
  5. ↑ Prossnitz, Eric R.; Barton, Matthias (2014). "Estrogen biology: New insights into GPER function and clinical opportunities". Molecular and Cellular Endocrinology. 389 (1-2): 71–83. doi:10.1016/j.mce.2014.02.002. ISSN 0303-7207.
  6. ↑ Stockholm Convention. Listing of POPs in the Stockholm Convention: Annex A (Elimination). 2011; Available from: http://chm.pops.int/Convention/The%20POPs/tabid/673/language/fr-CH/Default.aspx.
  7. ↑ Jack Cooksey, "What's in the Water?", Richmond Magazine, June 2007, accessed 13 June 2012.
  8. ↑ Durimel, A., et al., "pH dependence of chlordecone adsorption on activated carbons and role of adsorbent physico-chemical properties". Chemical Engineering Journal, 2013. 229: p. 239-349.
  9. ↑ Wong, A., and C. Ribero (2013). "Alternative agricultural cropping options for chlordecone-Polluted Martinique". Revue Etudes Caribéenens, n° 26, .
  10. ↑ Agard-Jones, Vanessa (2013-11-01). "Bodies in the System". Small Axe. 17 (3 42): 182–192. doi:10.1215/07990537-2378991. ISSN 0799-0537.
  11. ↑ European Journal, Deutsche Welle, 26 May 2010.
  12. ↑ Survey of Industrial Chemistry by Philip J. Chenier (2002), p. 484.
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