Dieldrin: Difference between revisions

| = changed

| verifiedrevid = 460784423

| Name = Dieldrin

| ImageFile1 = Dieldrin-3D-balls.png

| ImageFile2 = Dieldrin.svg

| ImageName = Dieldrin

| IUPACName = (1a''R'',2''R'',2a''S'',3''S'',6''R'',6a''R'',7''S'',7a''S'')-3,4,5,6,9,9-hexachloro-1a,2,2a,3,6,6a,7,7a-octahydro-2,7:3,6-dimethanonaphtho[2,3-''b'']oxirene

| OtherNames = Dieldrin, HEOD

|Section1={{Chembox Identifiers

| UNII_Ref = {{fdacite|correct|FDA}}

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChEMBL = 481118

| CASNo_Ref = {{cascite|correct|CAS}}

| KEGG_Ref = {{keggcite||kegg}}

| ChEBI_Ref = {{ebicite||EBI}}

| PubChem = 969491

|Section2={{Chembox Properties

|C=12|H=8|Cl=6|O=1

| MolarMass = 380.91 g/mol

| Density = 1.75 g/cm

| 177

| MeltingPt_notes =

| BoilingPtC = 385

| Appearance = colorless to light tan crystals

| Solubility = 0.02%<ref name=PGCH/>

|Section7={{Chembox Hazards

| PEL = TWA 0.25 mg/m³ [skin]<ref name=PGCH>{{PGCH|0206}}</ref>

| IDLH = Ca [50 mg/m³]<ref name=PGCH/>

| REL = Ca TWA 0.25 mg/m³ [skin]<ref name=PGCH/>

| MainHazards = moderately toxic and a suspected [[carcinogen]]<ref name=PGCH/>

| LD50 = 45 mg/kg (oral, rabbit)<br/>49 mg/kg (oral, guinea pig)<br/>38 mg/kg (oral, mouse)<br/>65 mg/kg (oral, dog)<br/>38 mg/kg (oral, rat)<ref name=IDLH>{{IDLH|60571|Dieldrin}}</ref>

| FlashPt = noncombustible

| FlashPt_ref = <ref name=PGCH/>

| LC50 = 80 mg/m³ (cat, 4 hr)<br/>13 mg/m³ (rat, 4 hr)<ref name=IDLH/>

}} }}

'''Dieldrin''' is [[ ]] originally produced in 1948 by J. Hyman & Co, Denver, as an [[insecticide]]. Dieldrin is closely related to [[aldrin]], which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the [[Diels-Alder reaction]] which is used to form aldrin from a mixture of norbornadiene and [[hexachlorocyclopentadiene]].

However, it is an extremely [[persistent organic pollutant]]; it does not easily [[biodegradation|break down]]. Furthermore it tends to [[biomagnify]] as it is passed along the [[food chain]]. Long-term exposure has proven toxic to a very wide range of animals including humans, far greater than to the original insect targets. For this reason it is now [[ban (law)|banned]] in most of the world.

It has been linked to health problems such as [[Parkinson's]], [[breast cancer]], and immune, reproductive, and nervous system damage. It also adversely affect in the [[fetus]] .

====

can be formed from the of hexachloro-1,3-cyclopentadiene with [[norbornadiene]] [[]] .<ref name="Tedder">{{cite book | =Jubb |year=1975

[[Image:DieldrinSynthesis.png|thumbnail||480px|Synthesis of ]]

Technical dieldrin contains 5-15% related polychloroepoxyoctahydro-

dimethanonaphthalenes.<ref name="IPCS89">{{cite book |last1=International Program of Chemical Safety |title=Aldrin and Dieldrin, Environmental Health Criteria 91 |date=1989 |publisher=WHO |location=Geneva |isbn=92-4-154291-8 |url=https://wedocs.unep.org/handle/20.500.11822/29406}}</ref><ref name="IARC2019">{{cite book |last1=International Agency for Research on Cancer |title=Aldrin and dieldrin, in: Pentachlorophenol and Some Related Compounds. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 117|date=2019 |publisher=IARC/WHO Press |location=Lyon |isbn=978-92-832-0184-7 |pages=193–322 |url=https://www.ncbi.nlm.nih.gov/books/NBK543329/pdf/Bookshelf_NBK543329.pdf}}</ref>

The estimated combined production volume of aldrin and dieldrin in the US peaked in the mid-1960s at about 20 million pounds a year (2 million pounds of dieldrin) and then declined.<ref name="Jorgensen2001">{{cite journal |last1=Jorgensen |first1=JL. |title=Aldrin and dieldrin: A review of research on their production environmental deposition and fate, bioaccumulation, toxicology, and epidemiology in the United States |journal=Environmental Health Perspectives |date=2001 |volume=109 (Suppl.) |issue=Suppl 1 |pages=113–39 |doi=10.1289/ehp.01109s1113 |pmid=11250811 |pmc=1240548 }}</ref>

== ==

and aldrin were widely applied in agricultural areas throughout and . are toxic and bioaccumulative. Aldrin does break down to dieldrin in living systems but dieldrin is known to resist bacterial and chemical breakdown processes in the environment.

Aldrin was used to control soil pests (namely termites) on corn and potato crops. Dieldrin was an insecticide used on fruit, soil, and seed. It persists in the soil with a half-life of five years at temperate latitudes. Both aldrin and dieldrin may be volatilized from sediment and redistributed by air currents, contaminating areas far from their sources. have been measured in Arctic wildlife suggesting long range transport from southern agricultural regions ( . 2000

== Metabolism ==

The metabolism of dieldrin occurs by various routes. Hydration of the [[epoxy group]] by [[epoxide hydrolase]]s leads to formation of the ''trans''-diol and to the [[dicarboxylic acid]]. The diol is the most important metabolite produced by the rabbit.<ref name="ATSDR 2022">{{cite book |publisher=Agency for Toxic Substances and Disease Registry |title=Toxicological Profile for Aldrin and Dieldrin |date=2022 |location=Atlanta |pages=94–98 |pmid=37040456 |url=https://www.ncbi.nlm.nih.gov/books/NBK590454/ |access-date=12 August 2023}}</ref> In the rat, the primary route of metabolism is [[hydroxylation]] of the CH₂ group by liver microsomal monooxygenases, leading to production of 9-hydroxydieldrin.<ref name="ATSDR 2022"/> There is hydrogen bonding between the OH and the epoxy group. It is excreted in the faeces.<ref name="Matsumura1985">{{cite book |last1=Matsumura |first1=Fumio |title=Toxicology of insecticides |date=1985 |publisher=Plenum Press |isbn=0-30641979-3 |pages=240–242 |edition=2nd}}</ref> It is likely that this is an example of [[enterohepatic recirculation]], for bile contains the [[glucuronide]]. This is probably cleaved by gut microflora.

There is an interesting metabolite in rat urine, first described by Klein.<ref>{{Cite journal |last1=Klein |first1=A K |last2=Link |first2=J D |last3=Ives |first3=N F |date=1968 |title=Isolation and Purification of Metabolites Found in the Urine of Male Rats Fed Aldrin and Dieldrin |journal=Journal of AOAC International |volume=51 |issue=4 |pages=895–898 |doi=10.1093/jaoac/51.4.895|doi-access=free }}</ref> The [[methylene group]] of the dieldrin links to one end of the ClC:CCl group to form a cage structure. The other end of the original ClC:CCl is converted to a [[ketone]]. The same metabolite is produced from the [[Photoisomerization|photoisomer]] of dieldrin, in which the same cage structure is produced, but the other end of the original chlorinated double bond forms a CHCl group.

{{clear|left}}

==Legislation and history==

Both aldrin and dieldrin have been banned in most developed countries, but aldrin is still used as a termiticide in Malaysia, Thailand, Venezuela and parts of Africa. In Canada, their sale was restricted in the mid-1970s, with the last registered use of the compounds in Canada being withdrawn in 1984.<ref>{{cite web |author1=Environment Canada |author1-link=Environment Canada |title=Descriptions of some toxic contaminants found in the Pacific and Yukon Region |url=http://www.ecoinfo.org/env_ind/region/toxin_descript/toxin_description_e.cfm |website=Ecoinfo |archive-url=https://web.archive.org/web/20120313081152/http://www.ecoinfo.org/env_ind/region/toxin_descript/toxin_description_e.cfm |archive-date=13 March 2012}}</ref>

The [[International Programme on Chemical Safety]] quotes the World Health Organization as stating dieldrin is prohibited for use in agriculture in, among others, Brazil, Ecuador, Finland, the German Democratic Republic, Singapore, Sweden, Yugoslavia, and the USSR. The European Community legislation prohibits the marketing of phytopharmaceutical products containing dieldrin. In Argentina, Canada, Chile, the Federal Republic of Germany, Hungary, and the US, its use is prohibited, with some exceptions. The use of dieldrin is restricted in India, Mauritius, Togo, and the United Kingdom. Its use in industry is prohibited in Switzerland and its manufacture and use in Japan is under government control. In Finland, the only accepted use for dieldrin is as a [[termiticide]] in one glue mixture for exported plywood. India requires registration and licences for all importation, manufacture, sale, or storage.

Momentum against organochlorine and similar molecules continued to grow internationally, leading to negotiations that matured as the [[Stockholm Convention on Persistent Organic Pollutants]](POPs). POPs are defined as hazardous and environmentally persistent substances which can be transported between countries by the Earth's oceans and atmosphere.

Most POPs (including dieldrin) bioaccumulate in the fatty tissues of humans and other animals. The Stockholm Convention banned twelve POPs, nicknamed "the dirty dozen". These include [[aldicarb]], [[toxaphene]], [[chlordane]] and [[heptachlor]], [[chlordimeform]], [[chlorobenzilate]], [[DBCP]], DDT, "'''drins'''" (aldrin, dieldrin and endrin), EDB, HCH and [[lindane]], [[paraquat]], [[parathion]] and [[methylparathion]], [[pentachlorophenol]], and [[2,4,5-T]]. This took force on 17 May 2004. Australia ratified the Convention only three days later and became a party to it in August that year.<ref name=":0" />

Legislation in Australia on the import, use and disposal of dieldrin and other organochlorines has been extensive and covers mainly environmental and potential health impacts on the population.<ref name=":0" />

==Australia==

The use of organochlorines in Australia was dramatically lowered between the mid-1970s and the early 1980s. The first restrictions on the use of dieldrin and related chemicals in Australia were introduced in 1961–2, with registration required for their use on produce animals, such as cattle and chickens. This coincided with increasing concerns worldwide about the long-term effects of persistent pesticides. The publication of ''[[Silent Spring]]'' (an account of the environmental and health effects of pesticides) by [[Rachel Carson]] in 1962 was a key driving force in raising this concern. The phase-out process was driven by government bans and deregistration, in turn promoted by changing public perceptions that food containing residues of these chemicals was less acceptable and possibly hazardous to health.<ref name=":0">{{Cite web|date=10 November 2008|title=Dieldrin and Breast Cancer: a Literature Review|url=https://www.dea.org.au/images/general/dieldrin_CB_Nov_10_2008.pdf|access-date=3 September 2020|archive-date=3 April 2018|archive-url=https://web.archive.org/web/20180403084325/https://www.dea.org.au/images/general/dieldrin_CB_Nov_10_2008.pdf|url-status=dead}}</ref>

Throughout this time, continuous pressure was maintained by relevant committees, for example the Technical Committee on Agricultural Chemicals (TCAC), to reduce approved organochlorine use. By 1981, the use of dieldrin worldwide was limited to sugarcane and bananas, and these uses were deregistered by 1985. In 1987, a nationwide recall system was put into place, and in December of that year, the government prohibited all imports of these chemicals into Australia without express ministerial approval. In 1994, the National Registration Authority for Agricultural and Veterinary Chemicals published a use of organochlorines in termite control, recommending the phase-out of organochlorines used in termite control upon development of viable alternatives. The same year, the Agriculture and Resource Management Council of Australia and New Zealand decided to phase out remaining organochlorine uses by 30 June 1995, with the exception of the Northern Territory. In November 1997, the use of all organochlorines other than [[mirex]] was phased out in Australia. Remaining stocks of mirex are to be used only for contained baits for termites in plantations of young trees in the Northern Territory until stocks run out, which is expected in the near future.<ref name=":0" />

The recognition of negative impacts on health has stimulated the implementation of multiple legislative policies in regards to the use and disposal of organochlorine pesticides. For example, the Environment Protection (Marine) Policy 1994 became operational in May 1995 in South Australia. It dictated the acceptable concentration of toxicants such as dieldrin in marine waters and the manner in which these levels must be tested and tried.<ref name=":0" />

== ==

{{reflist}}

== External links ==

* [http://www.dea.org.au/UserFiles/File/pdf_documents/dieldrin_CB_Nov_10_2008.pdf Dieldrin and Breast Cancer: a Literature Review, Australian National University / Doctors for the Environment Australia] {{Webarchive|url=https://web.archive.org/web/20091007144915/http://www.dea.org.au/UserFiles/File/pdf_documents/dieldrin_CB_Nov_10_2008.pdf |date=2009-10-07 }}

* Mandocdoc, M. and David, C.P. 2008. Dieldrin Contamination of the Groundwater in a Former US Military Base (Clark Air Base, Philippines). CLEAN Air, Soil, Water Journal 36 (10–11), 870–874.

* [http://www.inchem.org/documents/hsg/hsg/hsg021.htm#PartNumber:7 International Programme on Chemical Safety]

* [https://www.cdc.gov/niosh/npg/npgd0206.html CDC - NIOSH Pocket Guide to Chemical Hazards]

{{Insecticides}}

{{GABA receptor modulators}}

{{Androgen receptor modulators}}

{{Estrogen receptor modulators}}

{{Monoamine neurotoxins}}

[[Category:Aldehyde dehydrogenase inhibitors]]

[[Category:Obsolete pesticides]]

[[Category:Endocrine disruptors]]

[[Category:Epoxides]]

[[Category:GABAA receptor negative allosteric modulators]]

[[Category:Monoaminergic neurotoxins]]

[[Category:Nonsteroidal antiandrogens]]

[[Category:Persistent organic pollutants]]

[[Category:Persistent organic pollutants under the Convention on Long-Range Transboundary Air Pollution]]

[[Category:]]

[[Category:IARC Group 2A carcinogens]]