Glyphosate: Difference between revisions - Wikipedia

Article Images

Line 75:

With its heavy use in [[agriculture]], weed resistance to glyphosate is a growing problem. While glyphosate and formulations such as Roundup have been approved by regulatory bodies worldwide and are widely used, concerns about their effects on humans and the environment persist.<ref name=NatureonWHO2015/>

Glyphosate's mode of action as an herbicide is to inhibit a plant [[enzyme]] involved in the synthesis of the [[aromatic]] [[amino acid]]s: [[tyrosine]], [[tryptophan]], and [[phenylalanine]]. It is absorbed through [[foliage]], and minimally through roots,<ref>Sprankle, Paul, W. F. Meggitt, and Donald Penner. "Rapid inactivation of glyphosate in the soil." Weed Science (1975): 224-228.</ref><ref name="NPIC Data Sheet"/><ref name=moneuro/> and translocated to growing points. Because of this mode of action, it is only effective on actively growing plants; it is not effective as a [[preemergent herbicides|pre-emergence herbicide]]. Some crops have been [[genetic engineering|genetically engineered]] to be ~~tolerant~~resistant ofto glyphosate (i.e., Roundup Ready, also created by Monsanto Company). Such crops allow farmers to use glyphosate as a postemergence herbicide against both [[broadleaf]] and cereal weeds, but the development of ~~glyphosate~~similar resistance in some weed species is emerging as a costly problem. [[Genetically modified soybean#Roundup Ready Soybean|Roundup Ready soybean]] was the first Roundup Ready crop.

Many regulatory and scholarly reviews have evaluated the relative toxicity of glyphosate as an herbicide. The German [[Federal Institute for Risk Assessment]] published a toxicology review in 2013, which found that "the available data is contradictory and far from being convincing" with regard to correlations between exposure to glyphosate formulations and risk of various cancers, including [[non-Hodgkin lymphoma]] (NHL).<ref name=BFR2014>Renewal Assessment Report: Glyphosate, Volume 1, Report and Proposed Decision", German Institute for Risk Assessment, 18 December 2013, p. 65. Download available from [http://dar.efsa.europa.eu/dar-web/provision EFSA Provision of documents] (registration required){{rp|Volume 1, pp. 64–66}}</ref> A meta-analysis published in 2014 identified an increased risk of NHL in workers exposed to glyphosate formulations.<ref name=Schinasi/> In March 2015 the [[World Health Organization]]'s [[International Agency for Research on Cancer]] published a summary of its forthcoming monograph on glyphosate, and classified it as "probably carcinogenic in humans" ([[International Agency for Research on Cancer#IARC categories|category 2A]]) based on epidemiological studies, animal studies, and ''in vitro'' studies.<ref name=NatureonWHO2015/><ref name=Lancet20March2015>{{cite journal | vauthors = Guyton KZ, Loomis D, Grosse Y, El Ghissassi F, Benbrahim-Tallaa L, Guha N, Scoccianti C, Mattock H, Straif K | title = Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate | journal = The Lancet. Oncology | volume = 16 | issue = 5 | pages = 490–1 | date = May 2015 | pmid = 25801782 | doi = 10.1016/S1470-2045(15)70134-8 | url = http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045%2815%2970134-8/abstract }}</ref><ref name=IARC20March2015/>

Line 119:

In addition to its use as an herbicide, glyphosate is also used for [[crop desiccation]] (siccation) to increase harvest yield<ref name=moneuro>{{cite web| url=http://www.monsanto.com/products/Documents/glyphosate-background-materials/Agronomic%20benefits%20of%20glyphosate%20in%20Europe.pdf |title=The agronomic benefits of glyphosate in Europe| publisher=[[Monsanto]] Europe SA |date=February 2010| accessdate=2013-06-02}}</ref>

and, as a result of desiccation, to increase sucrose concentration in sugarcane before harvest.<ref name=LSUAgExt>~~Louisiana~~Lousisana State University Agricultural Extension Office. Last Updated: 3 September 2014 [http://www.lsuagcenter.com/en/crops_livestock/crops/sugarcane/harvesting_processing/Sugarcane-Ripener-Recommendations--Glyphosate.htm Sugarcane Ripener Recommendations - Glyphosate] Page Accessed 3 September 2014</ref>

== Formulations and tradenames ==

Line 150:

====Mammals====

The [[~~Lethal dose~~Lethal_dose#~~Median lethal dose~~ Median_lethal_dose_.28LD50.29|LD50]] of glyphosate is 5,000~~ ~~ mg/kg for rats, 10,000~~ ~~ mg/kg in mice and 3,530~~ ~~ mg/kg in goats. The acute dermal LD50 in rabbits is greater than 2 g/kg. Mammalian LD50s are considered to be low to very low toxicity. Signs of glyphosate toxicity in animals typically appear within 30 minutes to 2 hours following ingestion of a large enough dose, and include initial excitability and [[tachycardia]], [[ataxia]], depression and [[bradycardia]] but severe cases can develop into collapse and convulsions.<ref name="NPIC Data Sheet"/>

A review of unpublished short-term rabbit feeding studies reported severe toxicity effects at 150~~ ~~ mg/kg/day and "no observed adverse effect level" ([[NOAEL]]) doses ranging from 50 to 200~~ ~~ mg/kg/day.<ref>{{cite journal|last1=Kimmel|first1=Gary|title=Evaluation of developmental toxicity studies of glyphosate with attention to cardiovascular development|journal=Critical Reviews in Toxicology|date=2013|volume=43|issue=2|pages=~~79–95~~79-95|doi=10.3109/10408444.2012.749834|url=http://www.tandfonline.com/doi/full/10.3109/10408444.2012.749834#.VeW7M_lViko|accessdate=1 September 2015}}</ref>

Glyphosate can have carcinogenic effects in non-human mammals. These include the induction of positive trends in the incidence of [[Kidney cancer|renal tubule carcinoma]] and [[haemangiosarcoma]] in male mice, and increased [[Pancreatic cancer|pancreatic islet-cell adenoma]] in male rats.<ref name=Lancet20March2015 /> A 2015 review found that glyphosate may be toxic below the [[lowest-observed-adverse-effect level]] that has been assigned to it by regulators, and that its effects may include "teratogenic, tumorigenic and hepatorenal effects."<ref name="Mesnage">{{cite journal|author=Mesnage, R., Defarge, N., Spiroux de Vendômois, J. and Séralini, G.E.|title=Potential toxic effects of glyphosate and its commercial formulations below regulatory limits.|journal=Food and Chemical Toxicology|year=2015|volume=84|pages=133-153|doi=10.1016/j.fct.2015.08.012|pmid=26282372}}</ref>

===== Human toxicity =====

Line 162:

==== Fish and aquatic life====

In various freshwater fish species, pure glyphosate has a 48-hour lethal concentration (LC50) of greater than 24~~ ~~ mg/L to 140~~ ~~ mg/L, while marketed glyphosate formulations can range from 1.3~~ ~~ mg/L to greater than 1000~~ ~~ mg/L. Specific species LC50s include 140~~ ~~ mg/L for [[rainbow trout]] (''Onchorynchus mykiss''), 97~~ ~~ mg/L for [[fathead minnow]]s (''Pimephales promelas''), 130~~ ~~ mg/L for [[channel catfish]] (''Icalurus punctatus'') and 150~~ ~~ mg/L for [[bluegill sunfish]] (''Lepomis macrochirus''). For green frogs (''Rana clamitans'') it has a 24 and 96-hour LC50 of greater than 38.9 g/L. In freshwater invertebrates (species unspecified), glyphosate has a 48-hour LC50 ranging from 55 to 780 ppm. The 96-hour LC50 is 281 ppm for grass shrimps (''Palaemonetas vulgaris'') and 934 ppm for fiddler crabs (''Uca pagilator''). These values make glyphosate "slightly toxic to practically non-toxic".<ref name="NPIC Data Sheet"/>▼

Glyphosate is generally less persistent in water than in soil, with 12 to 60-day persistence observed in Canadian ponds, yet persistence of over a year has been recorded in the sediments of U.S. ponds.<ref name="epa_reds"/> Low glyphosate concentrations can be found in many creeks and rivers in the U.S. and in Europe.<ref name=autogenerated3>Pesticide Action Network Asia & the Pacific (PANAP) [http://www.panap.net/sites/default/files/monograph_glyphosate.pdf Glyphosate] 2009</ref> The half-life of glyphosate in water is between 12 days to 10 weeks.<ref name="Sparling">{{cite journal|author=Sparling, D.W., Matson, C., Bickham, J. and Doelling‐Brown, P.|year=2006|title=Toxicity of glyphosate as Glypro® and LI700 to red‐eared slider (Trachemys scripta elegans) embryos and early hatchlings|journal=Environmental Toxicology and Chemistry|volume=25|issue=10|pages=2768-2774}}</ref>

For green frogs (''Rana clamitans'') glyphosate has a 24 and 96-hour LC50 of greater than 38.9 g/L. A 2014 review found that amphibians have been identified as particularly sensitive to glyphosate formulations in their larval and tadpole stages of development, and toxicity has been extensively studied for those stages; toxicity for terrestrial life cycle stages is less well understood.<ref name=FreshRev2014/> The review found that "across the spectrum of organisms likely to be exposed to glyphosate in the aquatic environment, it has been shown that sensitivity to glyphosate (and the constituents of commercial formulas) is highly species-specific. A 2012 study on the toxic potential of environmentally relevant concentrations of glyphosate on [[wood frog]]s (''Rana sylvatica''), [[leopard frog]]s (''Rana pipiens pipiens'') and [[American toad]]s (''Bufo americanus'') reported a significant induction of morphological changes in the tadpoles of the three species, including alteration of the size of the tadpole tail. This indicates that the herbicide could be affecting the mechanisms of development that are normally used as defence responses against predators. These results showed that glyphosate "can have widespread and relevant effects on non target species."<ref name="Marin">{{cite book|chapter=Chapter 16 - Toxicity of Herbicides: Impact on Aquatic and Soil Biota and Human Health|author= Marin-Morales, M. A., de Campos Ventura-Camargo, B. and Hoshina, M.M.|year=2013|title=Herbicides–Current Research and Case Studies in Use|pages=~~399–443~~399-443|url=http://cdn.intechopen.com/pdfs-wm/44984.pdf}}</ref~~> Developmental toxicity appears to occur in the larval and tadpoles of the [[American toad]] at levels of exposure to glyphosate that occur in common use of the herbicide.<ref name=FreshRev2014/~~>▼

▲In various freshwater fish species, pure glyphosate has a 48-hour lethal concentration (LC50) of greater than 24 mg/L to 140 mg/L, while marketed glyphosate formulations can range from 1.3 mg/L to greater than 1000 mg/L. Specific species LC50s include 140 mg/L for [[rainbow trout]] (''Onchorynchus mykiss''), 97 mg/L for [[fathead minnow]]s (''Pimephales promelas''), 130 mg/L for [[channel catfish]] (''Icalurus punctatus'') and 150 mg/L for [[bluegill sunfish]] (''Lepomis macrochirus'').

A study observing the impact of herbicides on the [[biodiversity]] of aquatic communities containing algae and more than 25 species of animals showed that in contrast to [[2,4-D]], glyphosate had great impact in the community, causing a decrease of 22% of the species richness.<ref name="Marin" />▼

▲For green frogs (''Rana clamitans'') glyphosate has a 24 and 96-hour LC50 of greater than 38.9 g/L. A 2014 review found that amphibians have been identified as particularly sensitive to glyphosate formulations in their larval and tadpole stages of development, and toxicity has been extensively studied for those stages; toxicity for terrestrial life cycle stages is less well understood.<ref name=FreshRev2014/> The review found that "across the spectrum of organisms likely to be exposed to glyphosate in the aquatic environment, it has been shown that sensitivity to glyphosate (and the constituents of commercial formulas) is highly species-specific. A 2012 study on the toxic potential of environmentally relevant concentrations of glyphosate on [[wood frog]]s (''Rana sylvatica''), [[leopard frog]]s (''Rana pipiens pipiens'') and [[American toad]]s (''Bufo americanus'') reported a significant induction of morphological changes in the tadpoles of the three species, including alteration of the size of the tadpole tail. This indicates that the herbicide could be affecting the mechanisms of development that are normally used as defence responses against predators. These results showed that glyphosate "can have widespread and relevant effects on non target species."<ref name="Marin">{{cite book|chapter=Chapter 16 - Toxicity of Herbicides: Impact on Aquatic and Soil Biota and Human Health|author= Marin-Morales, M. A., de Campos Ventura-Camargo, B. and Hoshina, M.M.|year=2013|title=Herbicides–Current Research and Case Studies in Use|pages=399–443|url=http://cdn.intechopen.com/pdfs-wm/44984.pdf}}</ref> Developmental toxicity appears to occur in the larval and tadpoles of the [[American toad]] at levels of exposure to glyphosate that occur in common use of the herbicide.<ref name=FreshRev2014/>

Glyphosate is generally less persistent in water than in soil, with 12- to 60-day persistence was observed in a study of pond water in Canada, yet because glyphosate binds to soil, persistence of over a year has been observed in the sediments of ponds in Michigan and Oregon.<ref name="epa_reds"/>

In freshwater invertebrates (species unspecified), glyphosate has a 48-hour LC50 ranging from 55 to 780 ppm. The 96-hour LC50 is 281 ppm for grass shrimps (''Palaemonetas vulgaris'') and 934 ppm for fiddler crabs (''Uca pagilator''). These values make glyphosate "slightly toxic to practically non-toxic".<ref name="NPIC Data Sheet"/>

▲A study observing the impact of herbicides on the [[biodiversity]] of aquatic communities containing algae and more than 25 species of animals showed that in contrast to [[2,4-D]], glyphosate had great impact in the community, causing a decrease of 22% of the species richness.<ref name="Marin" />

==== Soil biota ====

Line 212 ⟶ 211:

Spreader 90 is a surfactant used in tank mixes.{{refn|Note: Prior versions were known as "X-77 Spreader".<ref name="Weed Handbook Glyphosate"/> This product itself had various versions: one included alkylphenol ethoxylate, [[alcohol ethoxylate]], [[tall oil]] fatty acid, [[Diethylene glycol|2,2' dihydroxydiethyl ethyl]], and [[Polydimethylsiloxane|dimethylpolysiloxane]].<ref>Loveland Products. [http://www.agrian.com/pdfs/X-77_Spreader_(Ltc0_105-F2607)_Label.pdf X-77 Spreader Label]</ref><ref>Loveland Products. [http://www.agrian.com/pdfs/X-77_(X77s-05-Lpi_030205)_MSDS.pdf Material Safety Data Sheet - X-77 Spreader]</ref> Another version included alkylarylpolyoxyethylene, alkylpolyoxyethylene, gatty acids, glycols and dimethylpolysiloxane.<ref>Loveland Products. [http://www.herbicide-adjuvants.com/adjuvants/db-labels/126.pdf alt X-77 Spreader Label]</ref>}} Spreader 90 contains 1,2 propanediol (also known as [[propylene glycol]]), propane 1,2,3 triol (also known as [[glycerol]]), [[alcohol ethoxylate]], and [[Polydimethylsiloxane|dimethylpolysiloxane]].<ref>Loveland Products. [http://www.cdms.net/ldat/ld4Q2010.pdf Spreader 90 Label]</ref><ref>Loveland Products. [http://www.cdms.net/ldat/mp4Q2009.pdf Spreader 90 Material Safety Data Sheet]</ref> Of these ingredients, alcohol ethoxylates are among the widely used detergents in consumer products; commercial preparations are often mixes of homologs. Due to known toxicities to aquatic species, the [[Canadian Environmental Protection Act, 1999]] recommended Federal Water Quality Guideline values of 70 µg/l.<ref>Staff, Environment Canada. February 2013 [http://www.ec.gc.ca/ese-ees/default.asp?lang=En&n=164786DB-1 Federal Environmental Quality Guidelines: Alcohol Ethoxylates]</ref>

=== ~~Glyphosate-based formulation~~Formulation toxicity ===

Glyphosate-based formulations (GBFs) may contain a number of [[Agricultural spray adjuvant|adjuvants]], the identities of which are considered trade secret<ref name="Hoy">{{cite journal|author=Hoy, J., Swanson, N. and Seneff, S.|journal=Poultry, Fish & Wildlife Sciences|year=2015|volume=3|issue=1|url=http://dx.doi.org/10.4172/2375-446X.100013|title=The high cost of pesticides: Human and animal disease}}</ref> and not disclosed by most government regulators. In the United States, the [[Federal Insecticide, Fungicide, and Rodenticide Act]] requires that all pesticides (including herbicides) be evaluated by the EPA prior to sale, including the product’s chemistry, environmental fate, residue chemistry, dietary and non-dietary hazards to humans, and hazards to domestic animals and non-target organisms.<ref>{{cite web |url=http://www.epa.gov/agriculture/lfra.html |title=Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) | Agriculture | US EPA |work= |accessdate=}}</ref> These evaluations are performed for each active ingredient, each inert ingredient, and for the final product formulation. Additional evaluations are performed by the [[FDA]] to set permitted residue levels in food for pesticide products used on food crops.<ref>{{cite web |url=http://www2.epa.gov/pesticide-registration/pesticide-registration-manual |title=Pesticide Registration Manual | Pesticide Registration | US EPA |format= |work= |accessdate=}}</ref>

[[Surfactants]] are used in herbicide formulations as [[wetting]] agents and [[Penetrant (biochemical)|penetrants]] to maximize coverage and aid penetration of the herbicide(s) through plant leaves. As [[agricultural spray adjuvant]]s, surfactants may be premixed in commercial formulations or they may be purchased separately and mixed on-site (tank mix).

[[Polyethoxylated tallow amine]] (POEA) is a surfactant used in the original Roundup formulation and is still commonly used today.<ref name=usgs.glyphosate.poea>{{cite web|title=Measuring POEA, a Surfactant Mixture in Herbicide Formulations|url=http://toxics.usgs.gov/highlights/glyphosate_poea.html|publisher=U.S. Geological Survey}}</ref> Different versions of Roundup have included different percentages of POEA. Although Monsanto [http://www.monsanto.com/sitecollectiondocuments/ito/roundup%20promax_factsheet_april%202010_final%20.pdf product fact sheets] do not disclose surfactants and their percentages, a 1997 US government report said that Roundup is 15% POEA while Roundup Pro is 14.5%.<ref name="fs.fed.us"/> A review of the literature provided to the EPA in 1997 found that POEA was more toxic to fish than glyphosate was.<ref name="fs.fed.us">Gary L. Diamond and Patrick R. Durkin February 6, 1997, under contract from the United States Department of Agriculture. [http://www.fs.fed.us/foresthealth/pesticide/pdfs/Surfactants.pdf Effects of Surfactants on the Toxicitiy of Glyphosate, with Specific Reference to RODEO]</ref>

==== Human ====

Line 245 ⟶ 236:

==== Other animals ====

A 2000 review of the ecotoxicological data on Roundup shows at least 58 studies exist on the effects of Roundup on a range of organisms.<ref name=Giesy2000>{{cite journal |doi=10.1007/978-1-4612-1156-3_2 |title=Ecotoxicological Risk Assessment for Roundup® Herbicide |journal=Reviews of Environmental Contamination and Toxicology |year=2000 | author =Giesy JP, Dobson S, Solomon KR | isbn = 978-0-387-95102-7 | volume = 167 | pages = 35–120 | url = http://books.google.com/books?id=7iTdm5ii4NYC&pg=PA35 | series = Reviews of Environmental Contamination and Toxicology }}</ref> This review concluded, "...for terrestrial uses of Roundup minimal acute and chronic risk was predicted for potentially exposed non-target organisms".▼

~~==== Fish and aquatic life====~~

Glyphosate formulations are much more toxic for amphibians and fish than glyphosate alone.<ref name="fs.fed.us"/> Glyphosate formulations may contain a number of so-called ‘inert’ ingredients or adjuvants, most of which are not publicly known as in many countries the law does not require that they be revealed.<ref name=autogenerated3>Pesticide Action Network Asia & the Pacific (PANAP) [http://www.panap.net/sites/default/files/monograph_glyphosate.pdf Glyphosate] 2009</ref> A 2003 study of various formulations of glyphosate found, "[the] risk assessments based on estimated and measured concentrations of glyphosate that would result from its use for the control of undesirable plants in wetlands and over-water situations showed that the risk to aquatic organisms is negligible or small at application rates less than 4 kg/ha and only slightly greater at application rates of 8 kg/ha.".<ref name=Solomon>{{cite journal | vauthors = Solomon KR, Thompson DG | title = Ecological risk assessment for aquatic organisms from over-water uses of glyphosate | journal = Journal of Toxicology and Environmental Health. Part B, Critical Reviews | volume = 6 | issue = 3 | pages = 289–324 | year = 2003 | pmid = 12746143 | doi = 10.1080/10937400306468 }}</ref> Serious sub-lethal effects on aquatic animals have been noted for formulations of glyphosate.<ref name="Sparling" />

The [[Lethal_concentration|LC50]] of formulations for [[Catla catla]] is 4.6 ppm<ref>{{cite journal|last1=Felix|first1=F|title=Impact of the Herbicide Glyphosate Roundup (41%) on the Haematology of the Freshwater Fish Catla Catla (Hamilton)|journal=Journal of Environmental Science, Toxicology, and Food Technology|date=2015|volume=9|issue=4|pages=56-60|accessdate=3 September 2015}}</ref>, 4.2 ppm for [[rainbow trout]] (''Oncorhynchus mykiss'') and 1.3 ppm for [[bluegill]] (Lepomis macrochirus)<ref name=NRA>{{cite book|title=NRA Special Review of Glyphosate|date=June 1996|publisher=Chemical Review Section, National Registration Authority for Agricultural and Veterinary Chemical, Australia|location=Canberra|url=http://apvma.gov.au/sites/default/files/publication/15106-glyphosate-review-final-report.pdf|accessdate=5 September 2015}}</ref> The 96 h-LC50 toxicity of Roundup for the [[neotropical]] fish ''[[Prochilodus lineatus]]'' is 13.69 mg/L, indicating this fish is more sensitive to Roundup than rainbow trout and [[Atlantic salmon]] (''Salmo salar'').<ref name="Carmo">{{cite journal|author=do Carmo Langiano, V. and Martinez, C.B.|year=2008|title==Toxicity and effects of a glyphosate-based herbicide on the Neotropical fish Prochilodus lineatus.|journal=Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology|volume=147|issue=2|pages=222-231}}</ref> Short-term exposure of ''Prochilodus lineatus'' to sub-lethal concentrations of Roundup results in biochemical, physiological and histological alterations. Histopathological changes are observed in the gills, livers and brains in other fishes at these concentrations.<ref name="Kelaniya">{{cite journal|author=Kelaniya, K.G.|year=2015|title=Effect of glyphosate-based herbicide, Roundup™ on territory deference of male Oreochromis mossambicus (Osteichthyes, Cichlidae) associated with mating behaviour.|journal=Sri Lanka J. Aquat. Sci.|volume=20|issue=1|pages=1-10}}</ref>.

▲A ~~2000~~ review of the ecotoxicological data on Roundup shows at least 58 studies ~~exist on~~of the effects of Roundup itself on a range of organisms exist.<ref name=Giesy2000>{{cite journal |doi=10.1007/978-1-4612-1156-3_2 |title=Ecotoxicological Risk Assessment for Roundup® Herbicide |journal=Reviews of Environmental Contamination and Toxicology |year=2000 | author =Giesy JP, Dobson S, Solomon KR | isbn = 978-0-387-95102-7 | volume = 167 | pages = 35–120 | url = http://books.google.com/books?id=7iTdm5ii4NYC&pg=PA35 | series = Reviews of Environmental Contamination and Toxicology }}</ref> This review concluded, "~~...~~for terrestrial uses of Roundup minimal acute and chronic risk was predicted for potentially exposed non-target organisms".

A 2013 [[meta-analysis]] reviewed the available data related to potential impacts of glyphosate-based herbicides on amphibians. According to the authors, the use of glyphosate-based pesticides cannot be considered the major cause of amphibian decline, the bulk of which occurred prior to the widespread use of glyphosate or in pristine tropical areas with minimal glyphosate exposure. The authors recommended further study of species- and development-stage chronic toxicity, of environmental glyphosate levels, and ongoing analysis of data relevant to determining what if any role glyphosate might be playing in worldwide amphibian decline, and suggest including amphibians in standardized test batteries.<ref>{{cite journal | vauthors = Wagner N, Reichenbecher W, Teichmann H, Tappeser B, Lötters S | title = Questions concerning the potential impact of glyphosate-based herbicides on amphibians | journal = Environmental Toxicology and Chemistry / SETAC | volume = 32 | issue = 8 | pages = 1688–700 | date = Aug 2013 | pmid = 23637092 | doi = 10.1002/etc.2268 }}</ref>

In reproductive toxicity studies performed in rats and rabbits, no adverse maternal or offspring effects were seen at doses below 175–293 mg/kg of body weight per day.<ref name="NPIC Data Sheet"/>

Line 351 ⟶ 336:

Some micro-organisms have a version of 5-enolpyruvoyl-shikimate-3-phosphate synthetase (EPSPS) resistant to glyphosate inhibition. A version of the enzyme that both was resistant to glyphosate and that was still efficient enough to drive adequate plant growth was identified by Monsanto scientists after much trial and error in an ''[[Agrobacterium]]'' strain called CP4, which was found surviving in a waste-fed column at a glyphosate production facility.<ref name="Green_2011">{{cite journal | vauthors = Green JM, Owen MD | title = Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management | journal = Journal of Agricultural and Food Chemistry | volume = 59 | issue = 11 | pages = 5819–29 | date = Jun 2011 | pmid = 20586458 | pmc = 3105486 | doi = 10.1021/jf101286h }}</ref><ref name="Pollegioni_2011">{{cite journal | vauthors = Pollegioni L, Schonbrunn E, Siehl D | title = Molecular basis of glyphosate resistance-different approaches through protein engineering | journal = The FEBS Journal | volume = 278 | issue = 16 | pages = 2753–66 | date = Aug 2011 | pmid = 21668647 | pmc = 3145815 | doi = 10.1111/j.1742-4658.2011.08214.x }}</ref><ref>{{cite book | author = Rashid A | title = Introduction to Genetic Engineering of Crop Plants: Aims and Achievements | year = 2009 | publisher = I K International | isbn = 978-93-80026-16-9 | pages = 259 }}</ref>{{rp|56}} This CP4 EPSPS gene was [[Cloning#Molecular cloning|cloned]] and [[Transfection|transfected]] into soybeans. In 1996, genetically modified soybeans were made commercially available.<ref name="urlMonsanto | Company History">{{cite web | url = http://www.monsanto.com/whoweare/Pages/monsanto-history.aspx | title = Company History | format = | work = Web Site | publisher = Monsanto Company }}</ref> Current glyphosate-resistant crops include soy, [[maize]] (corn), [[canola]], [[alfalfa]], and [[cotton]], with [[wheat]] still under development.

[[Genetically modified crops]] have become the norm in the United States. InFor ~~2015~~example, 89in 2010, 70% of all the corn, 9478% of ~~soybeans~~cotton, and 8993% of ~~cotton~~all ~~produced~~soybeans ~~in the US~~planted were ~~genetically modified to be~~ herbicide-~~tolerant~~resistant.<ref name=~~USDA1~~"urlusda.mannlib.cornell.edu">{{cite web~~|title=Adoption~~ of| ~~Genetically Engineered Crops in the U.S.|~~url = http://~~www~~usda.~~ers~~mannlib.~~usda~~cornell.~~gov~~edu/~~data-products~~usda/~~adoption-of-genetically-engineered-crops-in-the-us~~nass/~~recent~~Acre/2010s/2010/Acre-~~trends~~06-in30-~~ge-adoption~~2010.~~aspx~~pdf |~~website~~ title =~~Economic~~ ~~Research~~Acreage ~~Service~~| author = Hamer H | work = National Agricultural Statistics Board Annual Report, | publisher =~~USDA~~ United States Department of Agriculture |~~accessdate~~ date =26 ~~August~~2010-06-30 ~~2015~~}}</ref>

== See also ==