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			{{Short description|Herbicide}}
	{{Chembox		{{Chembox
	| Watchedfields = changed		| Watchedfields = changed
	| ImageFile_Ref = {{chemboximage|correct|??}}		| verifiedrevid = 443663905
			| ImageFile_Ref = {{chemboximage|correct|??}}
	| ImageFile = Atrazin.png		| ImageFile = AtrazineVector.svg
	| ImageName = Atrazine		| ImageName = Atrazine
	| ImageFile1 = Atrazine-3D-balls.png		| ImageFile1 = Atrazine-3D-balls.png
	| ImageName1 = Atrazine		| ImageName1 = Atrazine
	| IUPACName = 1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine		| PIN = 6-Chloro-''N''<sup>2</sup>-ethyl-''N''<sup>4</sup>-(propan-2-yl)-1,3,5-triazine-2,4-diamine
			| OtherNames = Atrazine<br/>1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine<br/>2-Chloro-4-ethylamino-6-isopropylamino-''s''-triazine<br/>6-Chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine
	| OtherNames = Atrazine
	| Section1 = {{Chembox Identifiers		|Section1={{Chembox Identifiers
			| ChEBI_Ref = {{ebicite|correct|EBI}}
	| verifiedrevid = 443403144
	| ChEBI_Ref = {{ebicite|correct|EBI}}
	| ChEBI = 15930		| ChEBI = 15930
			| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
	| DrugBank = DB07392		| DrugBank = DB07392
	| SMILES = Clc1nc(nc(n1)NC(C)C)NCC		| SMILES = Clc1nc(nc(n1)NC(C)C)NCC
	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}		| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
	| ChemSpiderID = 2169		| ChemSpiderID = 2169
	| PubChem = 2256		| PubChem = 2256
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	| CASNo_Ref = {{cascite|correct|CAS}}		| CASNo_Ref = {{cascite|correct|CAS}}
	| CASNo = 1912-24-9		| CASNo = 1912-24-9
	| RTECS =		| RTECS =
	}}		}}
	| Section2 = {{Chembox Properties		|Section2={{Chembox Properties
	| C=8|H=14|Cl=1|N=5		| C=8 | H=14 | Cl=1 | N=5
	| Appearance = colorless solid		| Appearance = Colorless solid
	| Density = 1.187 gcm<sup>−3</sup>		| Density = 1.187 g/cm<sup>3</sup>
	| Solubility = 7 mg/100 mL		| Solubility = 7 mg/100 mL
	| MeltingPtC = 175		| MeltingPtC = 175
	| BoilingPtC = 200		| BoilingPtC = 200
			| BoilingPt_notes = decomposes<ref name=PGCH/>
	| pKa =
	| pKb =		| pKa =
	| Viscosity =		| pKb =
			| Viscosity =
	}}		}}
	| Section3 = {{Chembox Structure		|Section3={{Chembox Structure
	| MolShape =		| MolShape =
	| Coordination =		| Coordination =
	| CrystalStruct =		| CrystalStruct =
	| Dipole =		| Dipole =
	}}		}}
	| Section7 = {{Chembox Hazards		|Section7={{Chembox Hazards
	| ExternalMSDS =		| ExternalSDS =
	| MainHazards =		| MainHazards =
	| FlashPt =		| FlashPt = Noncombustible
			| FlashPt_ref = <ref name=PGCH/>
	| RPhrases =
			| PEL = None<ref name=PGCH>{{PGCH|0043}}</ref>
	| SPhrases =
			| REL = TWA 5 mg/m<sup>3</sup><ref name=PGCH/>
			| IDLH = N.D.<ref name=PGCH/>
	}}		}}
	| Section8 = {{Chembox Related		|Section8={{Chembox Related
	| OtherAnions =		| OtherAnions =
	| OtherCations =		| OtherCations =
	| OtherCpds =		| OtherCompounds =
	}}		}}
	}}		}}
			'''Atrazine''' is a ] ] of the ] class.<ref name=EPAatrazine /> It is used to prevent pre-emergence broadleaf ]s in crops such as ] (corn),<ref name="DrinkTap.org"/> ]<ref name="DrinkTap.org">{{cite news |title=Water Info : What's In My Water?: Atrazine |url=https://drinktap.org/Water-Info/Whats-in-My-Water/Atrazine |publisher=DrinkTap.org |archive-url=https://web.archive.org/web/20180101024239/https://drinktap.org/Water-Info/Whats-in-My-Water/Atrazine |archive-date=1 January 2018}}</ref> and ] and on turf, such as golf courses and residential lawns. Atrazine's primary manufacturer is ] and it is one of the most widely used herbicides in the United States,<ref name=EPAatrazine /> Canadian,<ref name=:can>{{cite news |title=Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Atrazine |url=https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-atrazine.html |publisher=Health Canada |date=1 November 2011 |access-date=5 November 2022 |archive-date=5 November 2022 |archive-url=https://web.archive.org/web/20221105184514/https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-atrazine.html |url-status=live }}</ref> and Australian agriculture.<ref name="APVMAmain">{{cite web|url=http://apvma.gov.au/node/12371|title=Chemical Review: Atrazine|publisher=Australian Pesticides and Veterinary Medicines Authority|access-date=2015-02-11|date=2014-05-28|archive-date=2015-02-11|archive-url=https://web.archive.org/web/20150211172609/http://apvma.gov.au/node/12371|url-status=live}}</ref> Its use was banned in the ] in 2004, when the EU found groundwater levels exceeding the limits set by regulators, and Syngenta could not show that this could be prevented nor that these levels were safe.<ref name=EUban>European Commission. {{Webarchive|url=https://web.archive.org/web/20220315165754/https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2004.078.01.0053.01.ENG |date=15 March 2022 }} Decision 2004/248/EC - Official Journal L 078, Decision 2004/248/EC. March 16, 2004: Quote: "(9) Assessments made on the basis of the information submitted have not demonstrated that it may be expected that, under the proposed conditions of use, plant protection products containing atrazine satisfy in general the requirements laid down in Article 5(1)(a) and (b) of Directive 91/414/EEC. In particular, available monitoring data were insufficient to demonstrate that in large areas concentrations of the active substance and its breakdown products will not exceed 0,1 μg/L in groundwater. Moreover, it cannot be assured that continued use in other areas will permit a satisfactory recovery of groundwater quality where concentrations already exceed 0,1 μg/L in groundwater. These levels of the active substance exceed the limits in Annex VI to Directive 91/414/EEC and would have an unacceptable effect on groundwater." (10) Atrazine should therefore not be included in Annex I to Directive 91/414/EEC. (11) Measures should be taken to ensure that existing authorisations for plant protection products containing atrazine are withdrawn within a prescribed period and are not renewed and that no new authorisations for such products are granted."</ref><ref name=NYT2004>Danny Hakimfeb for the New York Times. February 23, 2015. {{Webarchive|url=https://web.archive.org/web/20161223091121/http://www.nytimes.com/2015/02/24/business/international/a-pesticide-banned-or-not-underscores-trans-atlantic-trade-sensitivities.html?_r=0 |date=2016-12-23 }}</ref>
	'''Atrazine''', 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine, an ] consisting of an s-]-ring is a widely used ]. Its use is controversial due to widespread contamination in drinking water and its associations with birth defects and menstrual problems when consumed by humans at concentrations below government standards.<ref name="NYT">{{cite news|url=http://www.nytimes.com/2009/08/23/us/23water.html?_r=1&hp=&pagewanted=all|title=Debating How Much Weed Killer Is Safe in Your Water Glass |last=Duhigg|first=Charles|date=August 22, 2009|publisher=The New York Times|accessdate=2009-09-10}}</ref> Although it has been banned in the ],<ref>{{cite web|url=http://www.apvma.gov.au/news_media/chemicals/atrazine.php#what_is |title=Chemicals in the News: Atrazine |publisher=Australian Pesticides and Veterinary Medicines Authority |date=2010-06-30 |accessdate=2010-11-28}}</ref> it is still one of the most widely used herbicides in the world.
			At least two significant Canadian farm well studies showed that atrazine was the most common contaminant found.<ref name=:can/> {{As of|2001}}, atrazine was the most commonly detected pesticide contaminating drinking water in the U.S.<ref name=USGS>Gilliom RJ et al. US Geological Survey {{Webarchive|url=https://web.archive.org/web/20131126164946/http://pubs.usgs.gov/circ/2005/1291/pdf/circ1291_chapter4.pdf |date=2013-11-26 }} March 2006, Revised February 15, 2007</ref>{{rp|44}} Studies suggest it is an ], an agent that can alter the natural hormonal system.<ref name=AtrazineChemSummEPA>{{Cite report|date=2007-04-24 |title=Atrazine: Chemical Summary. Toxicity and Exposure Assessment for Children's Health |url=http://www.epa.gov/teach/chem_summ/Atrazine_summary.pdf |publisher=U.S. Environmental Protection Agency |archive-url=https://web.archive.org/web/20120316130312/http://www.epa.gov/teach/chem_summ/Atrazine_summary.pdf |archive-date=2012-03-16 }}</ref> However, in 2006 the ] (EPA) had stated that under the ] "the risks associated with the pesticide residues pose a reasonable certainty of no harm",<ref name="EPATriazine"> {{webarchive |url=https://web.archive.org/web/20130601222524/http://www.epa.gov/oppsrrd1/cumulative/triazine_fs.htm |date=June 1, 2013 }}, June 22, 2006, EPA.</ref> and in 2007, the EPA said that atrazine does not adversely affect amphibian sexual development and that no additional testing was warranted.<ref name=EPAUpdateAmphib> {{Webarchive|url=https://web.archive.org/web/20150930062846/http://www.epa.gov/pesticides/reregistration/atrazine/atrazine_update.htm#amphibian |date=2015-09-30 }}, April 2010, EPA.</ref> The EPA's 2009 review<ref name="EPAPress"> {{Webarchive|url=https://web.archive.org/web/20160304110232/http://yosemite.epa.gov/opa/admpress.nsf/d0cf6618525a9efb85257359003fb69d/554b6abea9d0672f85257648004a88c1!OpenDocument |date=2016-03-04 }}, October 7, 2009, EPA.</ref> concluded that "the agency's scientific bases for its regulation of atrazine are robust and ensure prevention of exposure levels that could lead to reproductive effects in humans".<ref name="AtraUpdateHealth">EPA {{Webarchive|url=https://web.archive.org/web/20150930062846/http://www.epa.gov/pesticides/reregistration/atrazine/atrazine_update.htm#atrazine |date=2015-09-30 }} Current as of January 2013. Accessed March 15, 2014</ref> However, in their 2016 Refined Ecological Risk Assessment for Atrazine, it was stated that "it is difficult to make definitive conclusions about the impact of atrazine at a given concentration but multiple studies have reported effects to various endpoints at environmentally-relevant concentrations."<ref>{{cite web |title=Refined Ecological Risk Assessment for Atrazine |url=https://www.regulations.gov/document?D=EPA-HQ-OPP-2013-0266-0315 |publisher=EPA |access-date=12 October 2020 |page=184 |archive-date=11 September 2020 |archive-url=https://web.archive.org/web/20200911135522/https://www.regulations.gov/document?D=EPA-HQ-OPP-2013-0266-0315 |url-status=live }}</ref> EPA started a registration review in 2013.<ref name="AtraUpdateHealthB">EPA Current as of January 2013. Accessed March 15, 2014</ref>
			The EPA's review has been criticized, and the safety of atrazine remains controversial.<ref name=yorker> {{Webarchive|url=https://web.archive.org/web/20140702091502/http://www.newyorker.com/reporting/2014/02/10/140210fa_fact_aviv?currentPage=all |date=2014-07-02 }} by Rachel Aviv, '']'', 10 February 2014</ref><ref name="NYT">{{cite news|url=https://www.nytimes.com/2009/08/23/us/23water.html?_r=1&hp=&pagewanted=all|title=Debating How Much Weed Killer Is Safe in Your Water Glass|last=Duhigg|first=Charles|date=August 22, 2009|work=The New York Times|access-date=2015-05-02|archive-date=2018-11-07|archive-url=https://web.archive.org/web/20181107104048/https://www.nytimes.com/2009/08/23/us/23water.html?_r=1&hp=&pagewanted=all|url-status=live}}</ref><ref name=TillittFish>{{cite journal |vauthors=Tillitt DE, Papoulias DM, Whyte JJ, Richter CA |title=Atrazine reduces reproduction in fathead minnow (Pimephales promelas) |journal=Aquat. Toxicol. |volume=99 |issue=2 |pages=149–59 |year=2010 |pmid=20471700 |doi=10.1016/j.aquatox.2010.04.011 |url=https://zenodo.org/record/1258744 |access-date=2020-09-01 |archive-date=2022-03-15 |archive-url=https://web.archive.org/web/20220315165735/https://zenodo.org/record/1258744 |url-status=live }}</ref> EPA has however stated that "If at any time EPA determines there are urgent human or environmental risks from atrazine exposure that require prompt attention, we will take appropriate regulatory action, regardless of the status of the registration review process."<ref name=EPAatrazine>{{cite news|url=https://www.epa.gov/ingredients-used-pesticide-products/atrazine|title=Ingredients Used in Pesticide Products-Atrazine|work=US Environmental Protection Agency|access-date=2021-08-08|archive-date=2022-05-06|archive-url=https://web.archive.org/web/20220506084754/https://www.epa.gov/ingredients-used-pesticide-products/atrazine|url-status=live}}</ref>
	==Uses==		==Uses==
	Atrazine is used to stop pre- and post-emergence broadleaf and grassy ]s in major crops. The compound is both effective and inexpensive, and thus is well-suited to production systems with very narrow profit margins, as is often the case with maize. Atrazine is the most widely used herbicide in conservation tillage systems, which are designed to prevent soil erosion.		Atrazine is an ] that is used to stop pre- and post-emergence broadleaf and grassy ]s in crops such as ], ], ], ], ], and ] plantations, and triazine-tolerant ].<ref name="APVMAmain"/>
			In the ] as of 2014, atrazine was the second-most widely used herbicide after ],<ref name=yorker/> with {{convert|76|e6lb|e3MT|abbr=off}} of it applied each year,<ref>{{cite news | last = Walsh | first = Edward | title = EPA Stops Short of Banning Herbicide | url = http://www.waterconserve.org/shared/reader/welcome.aspx?linkid=19803 | pages = A14 | newspaper = Washington Post | date = 2003-02-01 | access-date = 2007-04-27 | archive-date = 2022-03-15 | archive-url = https://web.archive.org/web/20220315165734/http://www.waterconserve.org/shared/reader/welcome.aspx?linkid=19803 }}</ref><ref name=rupr>{{cite web|title=Restricted Use Products (RUP) Report: Six Month Summary List |publisher=] |url=http://www.epa.gov/opprd001/rup/rup6mols.htm |access-date=1 December 2009 |archive-url=https://web.archive.org/web/20100111030314/http://www.epa.gov/opprd001/rup/rup6mols.htm |archive-date=11 January 2010 }}</ref> nearly identical to its usage in 1974, of 76.8 million pounds.<ref>{{cite web |title=Pesticide Usage Survey of Agricultural, Governmental, and Industrial Sectors in the United States, 1974 |url=https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=91012P4O.txt |website=epa.gov |publisher=EPA |date=1977}}</ref> Atrazine continues to be one of the most widely used herbicides in Australian agriculture.<ref name="APVMAmain"/> Its effect on corn yields has been estimated from 1% to 8%, with 3–4% being the conclusion of one economics review.<ref name=Ackerman2007>{{Cite journal
	Its effect on yields has been estimated from 6% to 1%, with 3-4% being the conclusion of one review.<ref name=Ackerman2007>]. (2007). ''.'' International Journal of Occupational and Environmental Health.</ref> In another study looking at combined data from 236 university corn field trials from 1986–2005, atrazine treatments showed an average of 5.7 bushels more per acre than alternative herbicide treatments.<ref name=NCWSS>Fawcett, Richard S. (2008) ''.'' North Central Weed Science Society.</ref>
			| author = Ackerman, Frank
			| title = The economics of atrazine
			| journal = International Journal of Occupational and Environmental Health
			| volume = 13
			| issue = 4
			| pages = 437–445
			| year = 2007
			| pmid = 18085057
			| url = http://ase.tufts.edu/gdae/Pubs/rp/EconAtrazine.pdf
			| doi = 10.1179/oeh.2007.13.4.437
			| s2cid = 2655422
			| author-link = Frank Ackerman
			| access-date = 2010-11-28
			| archive-date = 2011-06-22
			| archive-url = https://web.archive.org/web/20110622114756/http://ase.tufts.edu/gdae/Pubs/rp/EconAtrazine.pdf
			| url-status = live
			}}</ref><ref>{{cite journal |title=BioOne Online Journals - A Rationale for Atrazine Stewardship in Corn |doi=10.1614/WS-06-104.1 |volume=55 |journal=]|pages=75–81|year = 2017|last1 = Swanton|first1 = Clarence J|last2= Gulden|first2= Robert H|last3= Chandler|first3= Kevin|s2cid=86209323 }}</ref> In another study looking at combined data from 236 university corn field trials from 1986 to 2005, atrazine treatments showed an average increase of {{Convert|5.7|USbu/acre}} (~{{Convert|400|kg/ha}}) than alternative herbicide treatments.<ref name=NCWSS>Fawcett, Richard S. " {{Webarchive|url=https://web.archive.org/web/20090514160003/http://www.ncwss.org/proceed/2008/abstracts/137.pdf |date=2009-05-14 }}", {{webarchive|url=https://web.archive.org/web/20140305163756/http://www.ncwss.org/about.php |date=March 5, 2014 }}, 2008</ref> Effects on sorghum yields have been estimated to be as high as 20%, owing in part to the absence of alternative weed control products that can be used on sorghum.<ref>{{cite journal |title=Market-level assessment of the economic benefits of atrazine in the United States | doi=10.1002/ps.3703 | pmid=24318916 |volume=70 | issue=11 |journal=]|pages=1684–1696|pmc=4282455|year = 2014|last1 = Mitchell|first1 = P. D}}</ref>
	==Chemistry and biochemistry==		==Chemistry and biochemistry==
			Atrazine was invented in 1958 in the ] laboratories as the second of a series of ]s.<ref>{{cite book|url=https://books.google.com/books?id=CdBpwokWL08C&pg=PA360|title=Modern Crop Protection Compounds, Volume 1|author=Wolfgang Krämer|year=2007|publisher=Wiley-VCH|isbn=978-3-527-31496-6}}{{Dead link|date=April 2023 |bot=InternetArchiveBot |fix-attempted=yes }} (dead link 22 June 2022)</ref>
	Atrazine is prepared from ], which is treated sequentially with ] and ]. Like other triazine herbicides, atrazine functions by binding to the ]-binding ] in ], which animals lack. Plant death results from starvation and oxidative damage caused by breakdown in the ] process. Oxidative damage is accelerated at high light intensity.<ref>Arnold P. Appleby, Franz Müller, Serge Carpy “Weed Control“ in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a28_165}}</ref>
			Atrazine is prepared from ], which is treated sequentially with ] and ]. Like other triazine herbicides, atrazine functions by binding to the ]-binding ] in ], which animals lack. Plant death results from starvation and oxidative damage caused by breakdown in the ] process. Oxidative damage is accelerated at high light intensity.<ref>{{Cite encyclopedia
			| last1 = Appleby | first1 = Arnold P.
			| last2 = Müller | first2 = Franz
			| last3 = Carpy | first3 = Serge
			| doi = 10.1002/14356007.a28_165
			| encyclopedia = Ullmann's Encyclopedia of Industrial Chemistry
			| year = 2001
			| isbn = 978-3-527-30673-2
			| chapter = Weed Control
			}}</ref>
			Atrazine's effects in humans and animals primarily involve the ]. Studies suggest that atrazine is an ] that can cause ].<ref name="AtrazineChemSummEPA"/>
			Atrazine has been found to act as an ] of the ].<ref name="ProssnitzBarton2014">{{cite journal |last1=Prossnitz |first1=Eric R. |last2=Barton |first2=Matthias |title=Estrogen biology: New insights into GPER function and clinical opportunities |journal=]|date=May 2014 |volume=389 |issue=1–2 |pages=71–83 |doi=10.1016/j.mce.2014.02.002 |pmid=24530924 |pmc=4040308 }}</ref> Atrazine has been shown to bind covalently to (chemically react with) a large number of mammalian proteins.<ref>{{cite journal |last1=Dooley |first1=G. P. |last2=Reardon |first2=K. F. |last3=Prenni |first3=J. E. |last4=Tjalkens |first4=R. B. |last5=Legare |first5=M. E. |last6=Foradori |first6=C. D. |last7=Tessari |first7=J. E. |last8=Hanneman |first8=W. H. |title=Proteomic Analysis of Diaminochlorotriazine Adducts in Wister Rat Pituitary Glands and LβT2 Rat Pituitary Cells |journal=]|date=April 2008 |volume=21 |issue=4 |pages=844–851 |doi=10.1021/tx700386f |pmid=18370413 }}</ref>
			==Environment==
			===Levels===
			Atrazine contamination of surface water (lakes, rivers, and streams) in the U.S. has been monitored by the EPA and has consistently exceeded levels of concern in two Missouri watersheds and one in Nebraska.<ref>{{cite web |url=http://www.epa.gov/pesticides/reregistration/atrazine/atrazine_update.htm |title=Atrazine Updates &#124; Pesticides &#124; US EPA |publisher=Epa.gov |access-date=2015-02-08 |archive-date=2015-09-30 |archive-url=https://web.archive.org/web/20150930062846/http://www.epa.gov/pesticides/reregistration/atrazine/atrazine_update.htm |url-status=live }}</ref> Monitoring of atrazine levels in community water systems in 31 high-use states found that levels exceeded levels of concern for infant exposure during at least one year between 1993 and 2001 in 34 of 3670 community water systems using surface water, and in none of 14,500 community water systems using groundwater.<ref>{{cite web|url=http://www.epa.gov/oppsrrd1/REDs/atrazine_combined_docs.pdf |title=www.epa.gov |archive-url=https://web.archive.org/web/20080625030339/http://www.epa.gov/oppsrrd1/REDs/atrazine_combined_docs.pdf |archive-date=2008-06-25 }}</ref> Surface water monitoring data from 20 high atrazine use watersheds found peak atrazine levels up to 147 parts per billion, with daily averages in all cases below 10 parts per billion.
	===Biodegradation===		===Biodegradation===
			] pathway|alt=Biodegradation - ] pathway]]
	Atrazine degrades in ] primarily by the action of ]s. <!--there's probably also a non-bio route-->The ] of atrazine in soil ranges from 13 to 261 days.<ref>, U.S. EPA, January, 2003.</ref> Atrazine ] can occur by two known pathways:
			Atrazine remains in soil for a matter of months (although in some soils can persist to at least four years)<ref name=AtrazineChemSummEPA/> and can migrate from soil to ]; once in groundwater, it degrades slowly. It has been detected in groundwater at high levels in some regions of the U.S. where it is used on some crops and turf. The U.S. Environmental Protection Agency expresses concern regarding contamination of surface waters (lakes, rivers, and streams).<ref name=AtrazineChemSummEPA />
			Atrazine degrades in ] primarily by the action of ]s. <!--there's probably also a non-bio route-->The ] of atrazine in soil ranges from 13 to 261 days.<ref> {{webarchive |url=https://web.archive.org/web/20080625030339/http://www.epa.gov/oppsrrd1/REDs/atrazine_combined_docs.pdf |date=June 25, 2008 }}, U.S. EPA, January, 2003.</ref> Atrazine ] can occur by two known pathways:
	#] of the C-Cl bond, followed by the ] and ] groups, catalyzed by the ] ]s called AtzA, AtzB, and AtzC. The end product of this process is ], itself unstable with respect to ammonia and carbon dioxide. The best characterized organisms that use this pathway are of '']'' sp. strain ADP.
	#Dealkylation of the ]s to give 2-chloro-4-hydroxy-6-amino-1,3,5-triazine, the degradation of which is unknown. This path also occurs in ''Pseudomonas'' species as well as a number of bacteria.<ref>Zeng Y, Sweeney CL, Stephens S, Kotharu P. (2004). Atrazine Pathway Map. Wackett LP. Biodegredation Database.</ref><ref name="wackett">{{cite journal |author=Wackett LP, Sadowsky MJ, Martinez B, Shapir N |title=Biodegradation of atrazine and related s-triazine compounds: from enzymes to field studies |journal=] |volume=58 |issue=1 |pages=39–45 |year=2002 |month=January |pmid=11831474 |doi= 10.1007/s00253-001-0862-y|url=}}</ref>
			#] of the C-Cl bond is followed by the ] and ] groups, catalyzed by the ] ]s called AtzA, AtzB, and AtzC. The end product of this process is ], itself unstable with respect to ammonia and carbon dioxide. The best characterized organisms that use this pathway are of '']'' sp. strain ADP.
	Rates of biodegradation are affected by atrazine's low solubility, thus ]s may increase the degradation rate. Though the two alkyl moieties readily support growth of certain microorganisms, the atrazine ring is a poor energy source due to the oxidized state of ring carbon. In fact, the most common pathway for atrazine degradation involves the intermediate, cyanuric acid, in which carbon is fully oxidized, thus the ring is primarily a nitrogen source for aerobic microorganisms. Atrazine may be ] as a carbon and nitrogen source in reducing environments, and some aerobic atrazine degraders have been shown to use the compound for growth under anoxia in the presence of nitrate as an electron acceptor,<ref>Crawford, J. J., G.K. Sims, R.L. Mulvaney, and M. Radosevich. 1998. Biodegradation of atrazine under denitrifying conditions. Appl. Microbiol. Biotechnol. 49:618-623.</ref> a process referred to as a ]. When atrazine is used as a nitrogen source for bacterial growth, degradation may be regulated by the presence of alternative sources of nitrogen. In pure cultures of atrazine-degrading bacteria, as well as active soil communitites, atrazine ring nitrogen, but not carbon are assimilated into microbial biomass.<ref>Bichat, F., G.K. Sims, and R.L. Mulvaney. 1999. Microbial utilization of heterocyclic nitrogen from atrazine. Soil Sci. Soc. Am. J. 63:100-110.</ref> Low concentrations of ] can decrease the bioavailability, whereas higher concentrations promote the catabolism of atrazine.<ref>{{cite journal | author = Ralebitso TK, Senior E, van Verseveld HW | year = 2002 | title = Microbial aspects of atrazine degradation in natural environments | journal = ] | volume = 13 | pages = 11–19 | doi = 10.1023/A:1016329628618}}</ref> <!--probably a crappy journal, certainly a crappy WP write up-->
			#Dealkylation of the ]s gives 2-chloro-4-hydroxy-6-amino-1,3,5-triazine, the degradation of which is unknown. This path also occurs in ''Pseudomonas'' species, as well as a number of bacteria.<ref>Zeng Y, Sweeney CL, Stephens S, Kotharu P. (2004). Atrazine Pathway Map. Wackett LP. Biodegredation Database.</ref><ref name="wackett">{{cite journal |last1=Wackett |first1=L. P. |last2=Sadowsky |first2=M. J. |last3=Martinez |first3=B. |last4=Shapir |title=Biodegradation of atrazine and related s-triazine compounds: from enzymes to field studies |journal=Applied Microbiology and Biotechnology |volume=58 |issue=1 |pages=39–45 |date=January 2002 |pmid=11831474 |doi= 10.1007/s00253-001-0862-y |first4=N.|s2cid=2998290 }}</ref>
			Rates of biodegradation are affected by atrazine's low solubility; thus ]s may increase the degradation rate. Though the two alkyl moieties readily support growth of certain microorganisms, the atrazine ring is a poor energy source due to the oxidized state of ring carbon. In fact, the most common pathway for atrazine degradation involves the intermediate, cyanuric acid, in which carbon is fully oxidized, thus the ring is primarily a nitrogen source for aerobic microorganisms. Atrazine may be ] as a carbon and nitrogen source in reducing environments, and some aerobic atrazine degraders have been shown to use the compound for growth under anoxia in the presence of nitrate as an electron acceptor,<ref>{{cite journal |vauthors=Crawford JJ, Sims GK, Mulvaney RL, Radosevich M | year = 1998 | title = Biodegradation of atrazine under denitrifying conditions | journal = Appl. Microbiol. Biotechnol. | volume = 49 | pages = 618–623 | doi = 10.1007/s002530051223 | pmid = 9650260 | issue = 5| s2cid = 5126687 }}</ref> a process referred to as a ]. When atrazine is used as a nitrogen source for bacterial growth, degradation may be regulated by the presence of alternative sources of nitrogen. In pure cultures of atrazine-degrading bacteria, as well as active soil communities, atrazine ring nitrogen, but not carbon are assimilated into microbial biomass.<ref>{{cite journal |author1=Bichat, F. |author2=G.K. Sims |author3=R.L. Mulvaney | year = 1999 | title = Microbial utilization of heterocyclic nitrogen from atrazine | journal = Soil Science Society of America Journal | volume = 63 | issue = 1 | pages = 100–110 | doi = 10.2136/sssaj1999.03615995006300010016x| bibcode = 1999SSASJ..63..100B }}</ref> Low concentrations of ] can decrease the bioavailability, whereas higher concentrations promote the catabolism of atrazine.<ref>{{cite journal | vauthors = Ralebitso TK, Senior E, van Verseveld HW | year = 2002 | title = Microbial aspects of atrazine degradation in natural environments | journal = ] | volume = 13 | issue = 1 | pages = 11–19 | doi = 10.1023/A:1016329628618 | pmid = 12222950 | s2cid = 21098999 | url = https://research.tees.ac.uk/en/publications/c8197257-2338-4626-8ca5-73f70b276b73 | access-date = 2019-10-29 | archive-date = 2022-03-15 | archive-url = https://web.archive.org/web/20220315165609/https://research.tees.ac.uk/en/publications/microbial-aspects-of-atrazine-degradation-in-natural-environments | url-status = live }}</ref>
	The ]s for enzymes AtzA-C have been found to be highly conserved in atrazine-degrading organisms worldwide. The prevalence of these genes could be due to the mass transfer of AtzA-C on a global scale. In ''Pseudomonas'' sp. ADP, the Atz genes are located noncontiguously on a ] with the genes for ] catabolism. This plasmid is ] to ] in the laboratory and could lead to the worldwide distribution, in view of the extensive release of atrazine and mercury. AtzA-C genes have also been found in a ], but are chromosomally located.<ref>{{cite journal | author = Cai B, Han Y, Liu B, Ren Y, Jiang S. | year = 2003 | title = Isolation and characterization of an atrazine-degrading bacterium from industrial wastewater in China | journal = ] | volume = 36 | pages = 272–276 | doi = 10.1046/j.1472-765X.2003.01307.x | pmid=12680937 | issue = 5}}</ref> The insertion elements flanking each gene suggest that they are involved in the assembly of this specialized catabolic pathway.<ref name="wackett"/> Two options exist for degradation of atrazine using microbes, ] or ].<ref name="wackett"/> Recent research suggests that microbial adaptation to atrazine has occurred in some fields where the herbicide is used repetitively, resulting in a decrease in herbicidal effectiveness.<ref>Krutz, L.J., D.L. Shaner, C. Accinelli, R.M. Zablotowicz, and W.B. Henry. 2008. Atrazine dissipation in s-triazine-adapted and non-adapted soil from Colorado and Mississippi: Implications of enhanced degradation on atrazine fate and transport parameters. Journal of Environmental Quality 37:848-857.</ref> Like the herbicides ] and ], atrazine is susceptible to rapid transformation in the presence of reduced iron-bearing soil clays, such as ferruginous smectites. In natural environments, some iron-bearing minerals are reduced by specific bacteria in the absence of oxygen, thus the abiotic transformation of herbicides by reduced minerals is viewed as "microbially induced".<ref>Xu, J., J. W. Stucki, J. Wu, J. Kostka, and G. K. Sims. 2001. Fate of atrazine and alachlor in redox-treated ferruginous smectite. Environmental Toxicology & Chemistry 20: 2717-2724.</ref>
			The ]s for enzymes ]-C have been found to be highly conserved in atrazine-degrading organisms worldwide. In '']'' sp. ADP{{Clarify|date=October 2023|reason=Is ADP a provisional name?}}, the Atz genes are located noncontiguously on a ] with the genes for ] catabolism. AtzA-C genes have also been found in a ], but are chromosomally located.<ref>{{cite journal |vauthors=Cai B, Han Y, Liu B, Ren Y, Jiang S | year = 2003 | title = Isolation and characterization of an atrazine-degrading bacterium from industrial wastewater in China | journal = ] | volume = 36 | pages = 272–276 | doi = 10.1046/j.1472-765X.2003.01307.x | pmid=12680937 | issue = 5| s2cid = 8003165 }}</ref> The insertion elements flanking each gene suggest that they are involved in the assembly of this specialized catabolic pathway.<ref name="wackett"/> Two options exist for degradation of atrazine using microbes, ] or ].<ref name="wackett"/> Like the herbicides ] and ], atrazine is susceptible to rapid transformation in the presence of reduced iron-bearing soil clays, such as ferruginous ]s. In natural environments, some iron-bearing minerals are reduced by specific bacteria in the absence of oxygen, thus the abiotic transformation of herbicides by reduced minerals is viewed as "microbially induced".<ref>{{cite journal |vauthors=Xu J, Stucki JW, Wu J, Kostka J, Sims GK | year = 2001 | title = Fate of atrazine and alachlor in redox-treated ferruginous smectite | journal = Environmental Toxicology and Chemistry | volume = 20 | pages = 2717–2724 | doi = 10.1002/etc.5620201210 | issue = 12| pmid = 11764154 | s2cid = 24221011 }}</ref>
	==Health and environmental effects==
	According to Extension Toxicology Network in the U.S., "The oral median Lethal Dose or {{LD50}} for atrazine is 3090 mg/kg in ]s, 1750 mg/kg in ], 750 mg/kg in ]s, and 1000 mg/kg in hamsters. The dermal LD<sub>50</sub> in rabbits is 7500 mg/kg and greater than 3000 mg/kg in rats. The 1-hour inhalation LC<sub>50</sub> is greater than 0.7 mg/L in rats. The 4-hour inhalation LC<sub>50</sub> is 5.2 mg/L in rats." <ref>, Extension Toxicology Network (Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University), June 1996.</ref>
	</ref>]]
	Atrazine was banned in the ] (EU) in 2004 because of its persistent groundwater contamination.<ref name=Ackerman2007/> In the ], however, atrazine is one of the most widely used herbicides, with 76 million pounds of it applied each year, in spite of the restriction that used to be imposed.<ref>{{cite news | last = Walsh | first = Edward | title = EPA Stops Short of Banning Herbicide | url = http://www.waterconserve.org/shared/reader/welcome.aspx?linkid=19803 | pages = A14 | publisher = Washington Post | date = 2003-02-01 | accessdate = 2007-04-27 }}</ref><sup>,</sup> <ref name=rupr>{{cite web|title = Restricted Use Products (RUP) Report: Six Month Summary List | work = | publisher = ] | date = | url = http://www.epa.gov/opprd001/rup/rup6mols.htm | accessdate = 1 December 2009}}</ref> Its ] effects, possible carcinogenic effect, and epidemiological connection to ] in men has led several researchers to call for banning it in the US.<ref name=Ackerman2007/>
			===Photolysis===
	Research results from the U.S. ]'s Agricultural Health Study published in 2011 concluded that "there was no consistent evidence of an association between atrazine use and any cancer site." The study tracked 57,310 licensed pesticied applicators over 13 years. <ref name=EHP2011>Beane Freeman, Laura E. (2011) ''.'' Environmental Health Perspetives.</ref> EPA also determined in 2000 "that atrazine is not likely to cause cancer in humans."<ref>, U.S. EPA, January, 2003.</ref>
			In 2016, photolytic degradation with 254&nbsp;nm ] was seen by the authors of a particular study as an efficient process, which could be used in pilot plants to reduce or eliminate compounds of the atrazine class or similar emerging contaminants, in effluents.<ref name=fdel> {{Webarchive|url=https://web.archive.org/web/20180502140748/https://www.researchgate.net/profile/Francisco_Pereira20/publication/310843049_Photolytic_Degradation_of_Herbicide_Atrazine_by_Radiation_Ultraviolet_UVC_An_Application_of_Green_Chemistry/links/5839959a08aef00f3bfbba30/Photolytic-Degradation-of-Herbicide-Atrazine-by-Radiation-Ultraviolet-UVC-An-Application-of-Green-Chemistry.pdf |date=2018-05-02 }}, Chemical Science International Journal 17(3): 1-10, 2016</ref>
	Some studies suggest that even the concentrations meeting U.S. federal standards may be dangerous, with implications for human ]s, low birth weights and menstrual problems.<ref name="NYT"/> Findings from further studies released in early 2010 have tended to support the conclusion that even low doses can increase health risks, leading to calls for further testing and renewed EPA evaluation of atrazine's safety.<ref>Amster, Randall. , '']'', March 19, 2010.</ref>
			==Toxicology==
	In August 2009, Atrazine was prominently featured in the New York Times as a potential cause of birth defects, low birth weights and menstrual problems when consumed at concentrations below federal standards.<ref name="NYT"/> A Natural Resources Defense Council's Report on Atrazine suggested that the EPA is ignoring atrazine contamination in surface and drinking water in the central United States.<ref name="NRDC,
			According to Extension Toxicology Network in the U.S., "The oral median Lethal Dose or {{LD50}} for atrazine is 3090&nbsp;mg/kg in ]s, 1750&nbsp;mg/kg in ], 750&nbsp;mg/kg in ]s, and 1000&nbsp;mg/kg in hamsters. The dermal LD<sub>50</sub> in rabbits is 7500&nbsp;mg/kg and greater than 3000&nbsp;mg/kg in rats. The 1-hour inhalation LC<sub>50</sub> is greater than 0.7&nbsp;mg/L in rats. The 4-hour inhalation LC<sub>50</sub> is 5.2&nbsp;mg/L in rats." The ] is 0.003&nbsp;mg/L and the ] is 0.035&nbsp;mg/kg/day.<ref> {{Webarchive|url=https://web.archive.org/web/20220401033349/http://extoxnet.orst.edu/pips/atrazine.htm |date=2022-04-01 }}, Extension Toxicology Network (Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University), June 1996.</ref>
	Poisoning the Well">{{cite news| url=http://graphics8.nytimes.com/packages/pdf/us/NRDC-Atrazine-report.pdf?scp=2&sq=atrazine&st=cse | work=The New York Times}}</ref>
			]
	===Effect on amphibians===		===Mammals===
	Atrazine is a suspected ], causing demasculinization in male ] even at low concentrations,<ref name="EU">{{cite news | author = Jennifer Lee | title = Popular Pesticide Faulted for Frogs' Sexual Abnormalities | date = 2003-06-19 | publisher = The New York Times | url = http://query.nytimes.com/gst/fullpage.html?res=9A05E6DB1138F93AA25755C0A9659C8B63}}</ref><ref>{{cite journal | author= ], Kelly Haston, Mable Tsui, Anhthu Hoang, Cathryn Haeffele, and Aaron Vonk | title=Atrazine-Induced Hermaphroditism at 0.1 ppb in American Leopard Frogs | url = http://www.ehponline.org/members/2003/5932/5932.html | format = Free full text | journal= ] | year=2003 | volume=111 | page= 568| doi=10.1289/ehp.5932 | issue= 4}}</ref> and an ] disruptor.<ref>{{cite journal | author = Mizota, K.; Ueda, H. | year = 2006 | url = http://toxsci.oxfordjournals.org/cgi/content/full/90/2/362#BDY | doi = 10.1093/toxsci/kfj087 | journal = ] | title = Endocrine Disrupting Chemical Atrazine Causes Degranulation through Gq/11 Protein-Coupled Neurosteroid Receptor in Mast Cells | volume = 90 | page = 362 | pmid = 16381660 | issue = 2}}</ref> A 2010 study found that atrazine rendered 75 percent of male ] sterile and turned one in 10 into females.<ref name=transgendered_frogs>Pesticide atrazine can turn male frogs into females
	retrieved from http://www.universityofcalifornia.edu/news/article/22933
	on March 5, 2010</ref> A 2002 study found that exposure to atrazine caused male ]s to turn into ] - frogs with both male and female sexual characteristics.<ref name="Briggs">Briggs, Helen. (April 15, 2002), . ''BBC News''. Retrieved on 2007-10-16.</ref> But another study, requested by EPA and funded by ], was unable to reproduce these results.<ref>Jooste et al., 2005 Gonadal Development of Larval Male Xenopus laevis Exposed to Atrazine in Outdoor Microcosms Environ. Sci. Technol. 39, 5255-5261</ref>
			A September 2003 review by the ] (ATSDR) stated that atrazine is "currently under review for pesticide re-registration by the EPA because of concerns that atrazine may cause cancer", but not enough information was available to "definitely state whether it causes cancer in humans." According to the ATSDR, one of the primary ways that atrazine can affect a person's health is "by altering the way that the reproductive system works. Studies of couples living on farms that use atrazine for weed control found an increase in the risk of preterm delivery, but these studies are difficult to interpret because most of the farmers were men who may have been exposed to several types of pesticides. Little information is available regarding the risks to children, however "aternal exposure to atrazine in drinking water has been associated with low fetal weight and heart, urinary, and limb defects in humans".<ref name=ATSDR>{{cite web | url = http://www.atsdr.cdc.gov/phs/phs.asp?id=336&tid=59 | publisher = Center for Disease Control, Agency for Toxic Substances and Disease Registry, Division of Toxicology and Human Health Sciences | title = Public Health Statement for Atrazine | website = Toxic Substances Portal - Atrazine | date = September 2003 | access-date = May 2, 2015 | archive-date = March 15, 2022 | archive-url = https://web.archive.org/web/20220315165658/https://wwwn.cdc.gov/TSP/PHS/PHSLanding.aspx?id=336&tid=59 | url-status = dead }}</ref> Incidence of a birth defect known as ] appears to be higher in areas where surface water atrazine levels are elevated especially when conception occurs in the spring, the time when atrazine is commonly applied.<ref>{{Cite journal | title= Agricultural-related chemical exposures, season of conception, and risk of gastroschisis in Washington State | journal =American Journal of Obstetrics and Gynecology | volume=202 | issue= 3 | pages= 241.e1–241.e6 | date = March 2010 | doi=10.1016/j.ajog.2010.01.023| pmid= 20207240 | last1 =Waller | first1 =Sarah A | last2 =Paul | first2 =Kathleen | last3 =Peterson | first3 =Suzanne E | last4 =Hitti | first4 =Jane E | doi-access =free }}</ref>
	], Department of Integrative Biology, University of California, notes that all of the studies that failed to conclude that atrazine caused hermaphroditism were plagued by poor experimental controls and were funded by Syngenta, one of the companies that produce the chemical.<ref>{{cite journal | author = Hayes, TB | year = 2004 | title = There Is No Denying This: Defusing the Confusion about Atrazine | journal = ] | volume = 54 | issue = 112 | pages = 1138–1149 | doi = 10.1641/0006-3568(2004)0542.0.CO;2 | issn = 0006-3568}}</ref> The U.S. ] (EPA) and its independent Scientific Advisory Panel (SAP) examined all available studies on this topic — including Hayes' work — and concluded that there are "currently insufficient data" to determine if atrazine affects amphibian development. Hayes, formerly part of the SAP panel, resigned in 2000 to continue studies independently.<ref>, BBC News. 31 October 2002</ref> The EPA and its SAP made recommendations concerning proper study design needed for further investigation into this issue. As required by the EPA, Syngenta conducted two experiments under Good Laboratory Practices (GLP) and inspection by the EPA and German regulatory authorities. The paper concluded "These studies demonstrate that long-term exposure of larval ''X. laevis'' to atrazine at concentrations ranging from 0.01 to 100 microg/l does not affect growth, larval development, or sexual differentiation."<ref>, ToxSci</ref> Another independent study in 2008 determined that "the failure of recent studies to find that atrazine feminizes ''X. laevis'' calls into question the herbicide's role in that decline." A report written in Environmental Science and Technology (May 15, 2008) cites the independent work of researchers in Japan, who were unable to replicate Hayes' work. "The scientists found no hermaphrodite frogs; no increase in aromatase as measured by aromatase mRNA induction; and no increase in vitellogenin, another marker of feminization." <ref>, Aquatic Toxicology</ref>
			The ]'s ] has classified atrazine as "not classifiable as to its carcinogenicity to humans" (]).<ref>{{cite journal | url=https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono73.pdf | volume=73 | journal=IARC Monographs on the Evaluation of Carcinogenic Risks to Humans | title=IARC MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS | publisher=] | access-date=2021-08-05 | archive-date=2022-03-26 | archive-url=https://web.archive.org/web/20220326104158/https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono73.pdf | url-status=live }}</ref>
	A study published in 2007 examined the relative importance of environmentally relevant concentrations of atrazine on trematode
	cercariae versus tadpole defense against infection. The principal finding of the present study was that susceptibility of wood frog tadpoles to infection by E. trivolvis is increased only when hosts are exposed to an atrazine concentration of 30 ng/L and not to 3 ng/L <ref>http://onlinelibrary.wiley.com/doi/10.1897/07-220.1/pdf</ref>
			The EPA determined in 2003 "that atrazine is not likely to cause cancer in humans".<ref> {{Webarchive|url=https://web.archive.org/web/20150930062846/http://www.epa.gov/pesticides/reregistration/atrazine/atrazine_update.htm#cancer |date=2015-09-30 }}, U.S. EPA, January, 2003.</ref>
	A 2008 study reported that tadpoles developed deformed hearts and impaired kidneys and digestive systems when exposed to atrazine in their early stages of life. Tissue malformation may have been induced by ectopic ], although a mechanism was not identified.<ref></ref>
			In 2006, the EPA stated, "the risks associated with the pesticide residues pose a reasonable certainty of no harm".<ref name="EPATriazine" /><ref name="EPAUpdateAmphib" />
	In 2009, ] Department of Plant Sciences researchers found the combination of the herbicides mesotrione and atrazine can make ] more nutritious. They found the herbicides directly up-regulate the carotenoid biosynthetic pathway in corn kernels, which is associated with the nutritional quality of sweet corn. Enhanced accumulation of lutein and zeaxanthin is important because dietary carotenoids function in suppressing aging eye diseases such as macular degeneration, now affecting 1.75 million older Americans.<ref></ref>
			In 2007, the EPA said, "studies thus far suggest that atrazine is an ]". The implications for children's health are related to effects during pregnancy and during sexual development, though few studies are available. In people, risks for preterm delivery and intrauterine growth retardation have been associated with exposure. Atrazine exposure has been shown to result in delays or changes in ] development in female rats; conflicting results have been observed in males. Male rats exposed via milk from orally exposed mothers exhibited higher levels of prostate inflammation as adults; immune effects have also been seen in male rats exposed in utero or while nursing.<ref name="AtrazineChemSummEPA" /> EPA opened a new review in 2009<ref name="EPAPress" /> that concluded that "the agency's scientific bases for its regulation of atrazine are robust and ensure prevention of exposure levels that could lead to reproductive effects in humans."<ref name="AtraUpdateHealth" /> Deborah A. Cory-Slechta, a professor at the University of Rochester in New York has said in 2014, "The way the E.P.A. tests chemicals can vastly underestimate risks." She has studied atrazine's effects on the brain and serves on the E.P.A.'s science advisory board. She further stated, "There's still a huge amount we don't know about atrazine."<ref name=yorker/>
	In 2010 the ] (APVMA), found the chemical safe to use:
			A ] report from 2009 said that the EPA is ignoring atrazine contamination in surface and drinking water in the central United States.<ref name="NRDC, Poisoning the Well">{{cite news | url=http://graphics8.nytimes.com/packages/pdf/us/NRDC-Atrazine-report.pdf?scp=2&sq=atrazine&st=cse | work=] | publisher=The New York Times | title=How the EPA is Ignoring Atrazine Contamination in Surface and Drinking Water in the Central United States | date=August 2009 | access-date=2010-12-19 | archive-date=2022-04-17 | archive-url=https://web.archive.org/web/20220417140446/https://graphics8.nytimes.com/packages/pdf/us/NRDC-Atrazine-report.pdf?scp=2&sq=atrazine&st=cse | url-status=live }}</ref>
	<blockquote>The conclusion of the APVMA at that time, based on advice from DEWHA, was that atrazine is unlikely to have an adverse impact on frogs at existing levels of exposure. This advice was consistent with findings by the US EPA in 2007 (see below) that atrazine does not adversely effect amphibian gonadal development.<ref name="apvma">, ], June 30, 2010</ref></blockquote>
			"There was no consistent evidence of an association between atrazine use and any cancer site". The study tracked 57,310 licensed pesticide applicators over 13 years.<ref name=EHP2011>Beane Freeman, Laura E. (2011) '' {{Webarchive|url=https://web.archive.org/web/20120328114218/http://ehp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=16CAEF820312206AF426693F83851464?articleURI=info%3Adoi%2F10.1289%2Fehp.1103561 |date=2012-03-28 }}.'' Environmental Health Perspectives.</ref>
	Furthermore, the APVMA responded to Hayes' 2010 published paper, , by stating that his findings "do not provide sufficient evidence to justify a reconsideration of current regulations which are based on a very extensive dataset."<ref name="apvma"/>
			A 2011 review of the mammalian reproductive toxicology of atrazine jointly conducted by the ] and the ] of the United Nations concluded that atrazine was not ]. Reproductive effects in rats and rabbits were only seen at doses that were toxic to the mother. Observed adverse effects in rats included ] in rates (at doses ≥50&nbsp;mg/kg per day), delays in sexual development in female rats (at doses ≥30&nbsp;mg/kg per day), and decreased birth weight (at doses ≥3.6&nbsp;mg/kg per day).<ref>{{cite web |url=https://www.who.int/water_sanitation_health/dwq/chemicals/antrazine.pdf?ua=1 |title=Chemical Hazards in Drinking Water - Atrazine |access-date=2015-02-08 |archive-date=2022-03-15 |archive-url=https://web.archive.org/web/20220315165558/https://www.who.int/water_sanitation_health/dwq/chemicals/antrazine.pdf?ua=1 |url-status=live }}</ref>
	A 2010 study conducted by the ] observed substantial adverse reproductive effects on fish from atrazine exposure at concentrations below the USEPA water-quality guideline.<ref></ref>
			A 2014 systematic review, funded by atrazine manufacturer Syngenta, assessed its relation to reproductive health problems. The authors concluded that the quality of most studies was poor and without good quality data, the results were difficult to assess, though it was noted that no single category of negative pregnancy outcome was found consistently across studies. The authors concluded that a causal link between atrazine and adverse pregnancy outcomes was not warranted due to the poor quality of the data and the lack of robust findings across studies. Syngenta was not involved in the design, collection, management, analysis, or interpretation of the data and did not participate in the preparation of the manuscript.<ref>{{Cite journal
			| pmid = 24797711
			| pmc = 4265844
			| year = 2014
			| last1 = Goodman
			| first1 = M
			| title = Atrazine and pregnancy outcomes: A systematic review of epidemiologic evidence
			| journal = Birth Defects Research Part B: Developmental and Reproductive Toxicology
			| volume = 101
			| issue = 3
			| pages = 215–36
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			| first2 = J. S.
			| last3 = Desesso
			| first3 = J. M.
			| last4 = Scialli
			| first4 = A. R.
			| doi = 10.1002/bdrb.21101
			}}</ref>
			===Amphibians===
			Atrazine has been a suspected ], with some studies reporting causing demasculinization in male ]s even at low concentrations.<ref name="EU">{{cite news | author = Jennifer Lee | title = Popular Pesticide Faulted for Frogs' Sexual Abnormalities | date = 2003-06-19 | work = The New York Times | url = https://www.nytimes.com/2003/06/19/us/popular-pesticide-faulted-for-frogs-sexual-abnormalities.html | access-date = 2018-07-27 | archive-date = 2022-03-15 | archive-url = https://web.archive.org/web/20220315165653/https://www.nytimes.com/2003/06/19/us/popular-pesticide-faulted-for-frogs-sexual-abnormalities.html | url-status = live }}</ref> A 2002 study by ], of the University of California, Berkeley, found that exposure caused male ]s to turn into ]&nbsp;– frogs with both male and female sexual characteristics.<ref name="Briggs">Briggs, Helen. (April 15, 2002), {{Webarchive|url=https://web.archive.org/web/20071007133213/http://news.bbc.co.uk/1/hi/sci/tech/1930658.stm |date=2007-10-07 }}. ''BBC News''. Retrieved on 2007-10-16.</ref><ref>{{Cite journal |last1=Hayes |first1=Tyrone |last2=Haston |first2=Kelly |last3=Tsui |first3=Mable |last4=Hoang |first4=Anhthu |last5=Haeffele |first5=Cathryn |last6=Vonk |first6=Aaron |date=2002-10-31 |title=Feminization of male frogs in the wild |url=https://www.nature.com/articles/419895a |journal=Nature |language=en |volume=419 |issue=6910 |pages=895–896 |doi=10.1038/419895a |pmid=12410298 |s2cid=4364535 |issn=1476-4687 |access-date=2022-12-04 |archive-date=2010-11-27 |archive-url=https://web.archive.org/web/20101127063026/http://www.nature.com/nature/journal/v419/n6910/full/419895a.html |url-status=live }}</ref> However, this study has not been able to be ],<ref name=eparesp>{{cite news | url = https://www.epa.gov/sites/default/files/2019-04/documents/5001-response.pdf | title = Summary of Atrazine Reregistration Activities | access-date = 2021-08-14 | archive-date = 2022-03-15 | archive-url = https://web.archive.org/web/20220315165634/https://www.epa.gov/sites/default/files/2019-04/documents/5001-response.pdf | url-status = live }}</ref> and a 2003 EPA review of this study concluded that overcrowding, questionable sample handling techniques, and the failure of the authors to disclose key details including sample sizes, dose-response effects, and the variability of observed effects made it difficult to assess the study's credibility and ecological relevance.<ref name=eparesp /><ref>{{cite web |url=http://www.epa.gov/scipoly/sap/meetings/2003/june/dereporthdemasculinizedfrogsafterexposureherbicideatrazineatlowecologicallyhayes2.pdf |title=www.epa.gov |website=EPA Scientific Advisory Panel |date=June 2003 |access-date=2014-10-24 |archive-date=2022-03-15 |archive-url=https://web.archive.org/web/20220315165751/https://www.epa.gov/scipoly/sap/meetings/2003/june/dereporthdemasculinizedfrogsafterexposureherbicideatrazineatlowecologicallyhayes2.pdf |url-status=live }}</ref> A 2005 study, requested by EPA and conducted under EPA guidance and inspection, was unable to reproduce Hayes' results.<ref name="Jooste-et-al-2005">{{cite journal |last1=Jooste |first1=Alarik M. |last2=Du Preez |first2=Louis H. |last3=Carr |first3=James A. |last4=Giesy |first4=John P. |last5=Gross |first5=Timothy S. |last6=Kendall |first6=Ronald J. |last7=Smith |first7=Ernest E. |last8=Van Der Kraak |first8=Glen L. |last9=Solomon |first9=Keith R. |title=Gonadal Development of Larval Male Xenopus laevis Exposed to Atrazine in Outdoor Microcosms |journal=Environmental Science & Technology |date=July 2005 |volume=39 |issue=14 |pages=5255–5261 |doi=10.1021/es048134q |pmid=16082954 |bibcode=2005EnST...39.5255J }}</ref>
			In 2010, the ] (APVMA) tentatively concluded that environmental atrazine "at existing levels of exposure" was not affecting amphibian populations in Australia consistent with the 2007 EPA findings.<ref name="apvma2010">, ], Original June 30, 2010, Archived by Internet Archive July 4, 2010</ref> APVMA responded to Hayes' 2010 published paper,<ref>{{cite journal | pmid = 20194757 | year = 2010 | last1 = Hayes | first1 = TB | last2 = Khoury | first2 = V | last3 = Narayan | first3 = A | last4 = Nazir | first4 = M | last5 = Park | first5 = A | last6 = Brown | first6 = T | last7 = Adame | first7 = L | last8 = Chan | first8 = E | last9 = Buchholz | first9 = D | last10 = Stueve | first10 = T. | last11 = Gallipeau | first11 = S. | title = Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis) | volume = 107 | issue = 10 | pages = 4612–7 | doi = 10.1073/pnas.0909519107 | pmc = 2842049 | journal = Proceedings of the National Academy of Sciences of the United States of America| display-authors = 8 | bibcode = 2010PNAS..107.4612H | doi-access = free }}</ref> that his findings "do not provide sufficient evidence to justify a reconsideration of current regulations which are based on a very extensive dataset."<ref name="apvma2010" />
			The EPA's Scientific Advisory Panel examined relevant studies and concluded in 2010, "atrazine does not adversely affect amphibian gonadal development based on a review of laboratory and field studies".<ref name=EPAUpdateAmphib/> It recommended proper study design for further investigation. As required by the EPA, two experiments were conducted under Good Laboratory Practices (GLP) and were inspected by EPA and German regulatory authorities, concluding 2009 that "long-term exposure of larval ''X. laevis'' to atrazine at concentrations ranging from 0.01 to 100 μg/L does not affect growth, larval development, or sexual differentiation".<ref>{{cite journal |last1=Kloas |first1=Werner |last2=Lutz |first2=Ilka |last3=Springer |first3=Timothy |last4=Krueger |first4=Henry |last5=Wolf |first5=Jeff |last6=Holden |first6=Larry |last7=Hosmer |first7=Alan |title=Does Atrazine Influence Larval Development and Sexual Differentiation in Xenopus laevis? |journal=Toxicological Sciences |date=February 2009 |volume=107 |issue=2 |pages=376–384 |doi=10.1093/toxsci/kfn232 |pmid=19008211 |pmc=2639758 }}</ref> A 2008 report cited the independent work of researchers in Japan, who were unable to replicate Hayes' work. "The scientists found no hermaphrodite frogs; no increase in aromatase as measured by aromatase mRNA induction; and no increase in ], another marker of feminization."<ref>{{cite journal |last1=Renner |first1=Rebecca |title=Atrazine Effects in Xenopus Aren't Reproducible |journal=Environmental Science & Technology |date=May 2008 |volume=42 |issue=10 |pages=3491–3493 |doi=10.1021/es087113j |pmid=18546678 |bibcode=2008EnST...42.3491R |doi-access=free }}</ref>
			The Atrazine Saga has been chronicled.<ref>{{cite journal |last1=Rohr |first1=Jason R. |title=The Atrazine Saga and its Importance to the Future of Toxicology, Science, and Environmental and Human Health |journal=Environmental Toxicology and Chemistry |year=2021 |volume=40 |issue=6 |pages=1544–1558 |doi=10.1002/etc.5037 |url=https://setac.onlinelibrary.wiley.com/doi/full/10.1002/etc.5037 }}</ref>
			===2012 Class action lawsuit===
			In 2012, Syngenta, manufacturer of atrazine, was the defendant in a class-action lawsuit concerning the levels of atrazine in human water supplies. Syngenta agreed to pay $105 million to reimburse more than one thousand water systems for "the cost of filtering atrazine from drinking water". The company denied all wrongdoing.<ref name=yorker/><ref> {{Webarchive|url=https://web.archive.org/web/20210506104414/http://atrazinesettlement.com/ |date=2021-05-06 }}, accessed August 23, 2013</ref><ref>Clare Howard for Environmental Health News. June 17, 2013 {{Webarchive|url=https://web.archive.org/web/20140330221647/http://www.environmentalhealthnews.org/ehs/news/2013/atrazine |date=2014-03-30 }}</ref>
			===2015 Canadian regulatory review===
			Prompted by the EU's 2004 ban, a regulatory review of the product in Canada by the ] was begun in 2015. On 31 March 2017 the review result was published and the PMRA decided to leave the product's registration unchanged. This was done because while the EU's ban was based on a legislated pollutant level of 0.1 μg/L, the Canadian regulations call for a home-grown "] in determining the risk to human health from pesticides in drinking water." The US drinking water standard of 3 μg/L is approximately the same to the Canadian standard of 5 μg/L. Both maximum pollutant levels in North America were not exceeded by the maximum pollutant level in Canadian data of 2.32 μg/L.<ref name="PMRA17">{{cite news |title=Re-evaluation Note REV2017-09, Special Review Decision: Atrazine |url=https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/decisions-updates/reevaluation-note/2017/atrazine-rev-2017-09.html |publisher=Pest Management Regulatory Agency |date=31 March 2017 |access-date=5 November 2022 |archive-date=5 November 2022 |archive-url=https://web.archive.org/web/20221105192643/https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/decisions-updates/reevaluation-note/2017/atrazine-rev-2017-09.html |url-status=live }}</ref>
	==See also==		==See also==
	* ]		* ]
	* ]		* ]
	* ]		* ]
	==References==		==References==
	{{Reflist|2}}		{{Reflist|colwidth=35em}}
	==Further reading==
	* {{cite journal |author=Fan W, Yanase T, Morinaga H, ''et al.'' |title=Atrazine-induced aromatase expression is SF-1 dependent: implications for endocrine disruption in wildlife and reproductive cancers in humans |journal=Environ. Health Perspect. |volume=115 |issue=5 |pages=720–7 |year=2007 |month=May |pmid=17520059 |pmc=1867956 |doi=10.1289/ehp.9758 |url=}}
	* ], , Truthout, March 19, 2010.
	*
	* {{cite journal|last=Rohr|first=JR|coauthors=McCoy K|date=Sept 23, 2009|title=A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians|journal=Environmental Health Perspectives|url=http://www.ehponline.org/docs/2009/0901164/abstract.html|pmid=20056568|volume=118|issue=1|pages=20–32|doi=10.1289/ehp.0901164|pmc=2831963}}
	* Published February 2008, Elsevier, ISBN 978-0-444-51167-6
	*{{cite web|url=http://ecologist.testing.net-genie.co.uk/investigations/health/83082/sex_lies_and_herbicides.html|title=Sex, lies and herbicides|last=Thomas|first=Pat|date=February/March 2006|publisher=''The Ecologist''}}
	==External links==		==External links==
			*- PubChem(National library of medicine) - atrazine
	* - maintained by ]
	* - an Atrazine specific news site		* - National Pesticide Information Center - Atrazine Fact Sheet
			* - CDC - NIOSH Pocket Guide to Chemical Hazards
	* - ]'s page about atrazine
			*{{PPDB|43}}
	{{Herbicides}}		{{Herbicides}}
			{{Estrogen receptor modulators}}
			{{Authority control}}
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