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==Inert ingredients==
==Inert ingredients==
Glyphosate-based formulations may contain a number of [[Agricultural spray adjuvant|adjuvants]], the identities of which are considered trade secrets.<ref name="www2.epa.gov">{{cite web |url=http://www2.epa.gov/pesticide-registration/pesticide-registration-manual |title=Pesticide Registration Manual &#124; Pesticide Registration &#124; US EPA |format= |work= |accessdate=}}</ref> Surfactants are used in herbicide formulations as [[wetting]] agents, to maximize coverage and aid penetration of the herbicide(s) through plant leaves. As agricultural spray adjuvants, surfactants may be mixed into commercial formulations, such as Roundup, or they may be purchased separately and mixed on-site (tank mix).
[[Surfactant]]s, [[solvent]]s and [[preservative]]s are inert ingredients that are commonly added to glyphosate-based herbicide formulations.<ref>{{Cite web| last = News| first = Crystal Gammon, Environmental Health| title = Weed-Whacking Herbicide Proves Deadly to Human Cells| work = Scientific American| accessdate = 2018-08-12| url = https://www.scientificamerican.com/article/weed-whacking-herbicide-p/}}</ref> [[Polyethoxylated tallow amine]] (POEA) is a surfactant added to Roundup and other herbicides that helps the glyphosate penetrate the plant surface.<ref name=SA /> Some [[surfactant]]s that are added to herbicide formulations may increase glyphosate's toxicity.<ref>{{Cite book| publisher = Academic Press| isbn = 978-0-12-385926-6| last1 = Gupta| first1 = Ramesh C.| last2 = Gupta| first2 = Ramesh Chandra| title = Veterinary Toxicology: Basic and Clinical Principles| date = 2012-03-29 |page=843 |url=https://books.google.com/books?id=2WP8jMLQs0sC&pg=PA843}}</ref>

[[Polyethoxylated tallow amine]] (POEA) is a surfactant used in the original Roundup formulation and was commonly used in 2015.<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. A 1997 US government report said that Roundup is 15% POEA while Roundup Pro is 14.5%.<ref name="fs.fed.us"/> Since POEA is more toxic to fish and amphibians than glyphosate alone, POEA is not allowed in aquatic formulations.<ref name="Langeland"/><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 Toxicity of Glyphosate, with Specific Reference to RODEO]</ref><ref name=Mann/><ref name="fs.fed.us"/> 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 | vauthors = Giesy JP, Dobson S, Solomon KR | isbn = 978-0-387-95102-7 | volume = 167 | pages = 35–120 | url = https://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".
===Toxicity===
====Human====
[[Acute toxicity]] and [[chronic toxicity]] are dose-related. Skin exposure to ready-to-use glyphosate formulations can cause irritation, and [[Contact dermatitis#Photocontact dermatitis|photocontact dermatitis]] has been occasionally reported. These effects are probably due to the preservative [[benzisothiazolin-3-one]]. Severe skin burns are very rare.<ref name="Bradberry_2004" /> Inhalation is a minor route of exposure, but spray mist may cause oral or nasal discomfort, an unpleasant taste in the mouth, or tingling and irritation in the throat. Eye exposure may lead to mild conjunctivitis. Superficial corneal injury is possible if irrigation is delayed or inadequate.<ref name="Bradberry_2004" />
Death has been reported after deliberate overdose.<ref name="Bradberry_2004">{{cite journal | vauthors = Bradberry SM, Proudfoot AT, Vale JA | title = Glyphosate poisoning | journal = Toxicological Reviews | volume = 23 | issue = 3 | pages = 159–67 | year = 2004 | pmid = 15862083 | doi = 10.2165/00139709-200423030-00003 | url = http://content.wkhealth.com/linkback/openurl?issn=1176-2551&volume=23&issue=3&spage=159 }}</ref><ref name="pmid22835958">{{cite journal | vauthors = Sribanditmongkol P, Jutavijittum P, Pongraveevongsa P, Wunnapuk K, Durongkadech P | title = Pathological and toxicological findings in glyphosate-surfactant herbicide fatality: a case report | journal = The American Journal of Forensic Medicine and Pathology | volume = 33 | issue = 3 | pages = 234–7 | date = Sep 2012 | pmid = 22835958 | doi = 10.1097/PAF.0b013e31824b936c }}</ref>
Ingestion of Roundup ranging from 85 to 200 ml (of 41% solution) has resulted in death within hours of ingestion, although it has also been ingested in quantities as large as 500 ml with only mild or moderate symptoms.<ref name="pmid1673618">{{cite journal |vauthors=Talbot AR, Shiaw MH, Huang JS, Yang SF, Goo TS, Wang SH, Chen CL, Sanford TR |title=Acute poisoning with a glyphosate-surfactant herbicide ('Roundup'): a review of 93 cases |journal=Human & Experimental Toxicology |volume=10 |issue=1 |pages=1–8 |date=Jan 1991 |pmid=1673618 |doi=10.1177/096032719101000101}}</ref> Consumption of over 85 ml of concentrated product are likely to cause serious symptoms in adults including burns due to corrosive effects as well as kidney and liver damage. More severe cases cause "respiratory distress, impaired consciousness, [[pulmonary edema]], infiltration on chest X-ray, shock, arrhythmias, renal failure requiring haemodialysis, metabolic acidosis, and hyperkalaemia" and death is often preceded by [[bradycardia]] and [[ventricular arrhythmia]]s.<ref name="Bradberry_2004" />

A 2000 review concluded that "under present and expected conditions of new use, there is no potential for Roundup herbicide to pose a health risk to humans".<ref name="wkc00">{{cite journal | vauthors = Williams GM, Kroes R, Munro IC | title = Safety evaluation and risk assessment of the herbicide Roundup and its active ingredient, glyphosate, for humans | journal = Regulatory Toxicology and Pharmacology | volume = 31 | issue = 2 Pt 1 | pages = 117–65 | date = Apr 2000 | pmid = 10854122 | doi = 10.1006/rtph.1999.1371 }}</ref> A 2002 review by the European Union reached the same conclusion.<ref name="urlec.europa.eu">{{cite web | url = http://ec.europa.eu/food/fs/ph_ps/pro/eva/existing/list1_glyphosate_en.pdf | archiveurl=https://web.archive.org/web/20160731190915/http://ec.europa.eu/food/fs/ph_ps/pro/eva/existing/list1_glyphosate_en.pdf |title= Review report for the active substance glyphosate |date= 2002-01-21 |format= |work= Commission working document |publisher= European Commission, Health and Protection Directorate-General: Directorate E – Food Safety: plant health, animal health and welfare, international questions: E1 - Plant Health |archivedate= 31 July 2016 }}</ref>

A 2012 meta-analysis of epidemiological studies (seven cohort studies and fourteen case-control studies) of exposure to glyphosate formulations found no correlation with any kind of cancer.<ref name="Mink_2012">{{cite journal |vauthors= Mink PJ, Mandel JS, Sceurman BK, Lundin JI |title= Epidemiologic studies of glyphosate and cancer: a review |journal= Regulatory Toxicology and Pharmacology |volume= 63 |issue=3 |pages= 440–52 |date= Aug 2012 |pmid= 22683395 |doi= 10.1016/j.yrtph.2012.05.012 }}</ref> The 2013 systematic review by the German Institute for Risk Assessment of epidemiological studies of workers who use pesticides, exposed to glyphosate formulations found no significant risk, stating that "the available data are contradictory and far from being convincing".<ref name=BFR2014/>{{rp|Volume 1, p64-66}} However, a 2014 meta-analysis of the same studies found a correlation between occupational exposure to glyphosate formulations and increased risk of [[B cell lymphoma]], the most common kind of non-Hodgkin lymphoma. Workers exposed to glyphosate were about twice as likely to get B cell lymphoma.<ref name="Schinasi">{{cite journal |vauthors= Schinasi L, Leon ME |title=Non-Hodgkin lymphoma and occupational exposure to agricultural pesticide chemical groups and active ingredients: a systematic review and meta-analysis |journal=International Journal of Environmental Research and Public Health |volume=11 |issue=4 |pages=4449–527 |date=Apr 2014 |pmid=24762670 |pmc=4025008 |doi=10.3390/ijerph110404449}}</ref> A 2015 systematic review of [[observational studies]] found no evidence that glyphosate exposure among pregnant mothers caused adverse developmental outcomes in their children.<ref>{{Cite journal|last=de Araujo|first=Jessica S. A.|last2=Delgado|first2=Isabella F.|last3=Paumgartten|first3=Francisco J. R.|date=2016-06-06|title=Glyphosate and adverse pregnancy outcomes, a systematic review of observational studies|journal=BMC Public Health|volume=16|pages=472|doi=10.1186/s12889-016-3153-3|issn=1471-2458|pmc=4895883|pmid=27267204}}</ref> A 2016 systematic review and meta-analysis found limited and weak evidence of an association between glyphosate exposure and risk of non-Hodgkin lymphoma and multiple myeloma, while no association was found between glyphosate and risk of other lymphohematopoietic cancers.<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866614/</ref> The same review noted that the positive associations found may be due to bias and confounding.<ref>{{Cite journal|last=Chang|first=Ellen T.|last2=Delzell|first2=Elizabeth|date=2016|title=Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers|journal=Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes|volume=51|issue=6|pages=402–434|doi=10.1080/03601234.2016.1142748|issn=1532-4109|pmc=4866614|pmid=27015139}}</ref>

====Aquatic fauna====
Glyphosate products for aquatic use generally do not use surfactants, and aquatic formulations do not use POEA due to aquatic organism toxicity.<ref name="Langeland">{{cite web |title=SS-AGR-104 Safe Use of Glyphosate-Containing Products in Aquatic and Upland Natural Areas |url=https://edis.ifas.ufl.edu/pdffiles/AG/AG24800.pdf |publisher=University of Florida |accessdate=13 August 2018}}</ref><ref name="url_backrounder_aquatic">{{cite web | url = https://monsanto.com/app/uploads/2017/06/bkg_amphib_05a.pdf | title =Response to "The impact of insecticides and herbicides on the biodiversity and productivity of aquatic communities" | date = 2005-04-01 | format = PDF | work = Backgrounder | publisher = Monsanto Company }}</ref><ref name="url_backgrounder_Aquatic_Australia">{{cite web | url = https://monsanto.com/app/uploads/2017/06/gly_austfrog_bkg.pdf | title = Aquatic Use of Glyphosate Herbicides in Australia | date = 2003-05-01 | format = PDF | work = Backgrounder | publisher = Monsanto Company }}</ref> Due to the presence of POEA, such glyphosate formulations only allowed for terrestrial use are more toxic for amphibians and fish than than glyphosate alone.<ref name="Langeland"/><ref name="fs.fed.us"/><ref name=Mann>{{cite journal | vauthors = Mann RM, Hyne RV, Choung CB, Wilson SP | title = Amphibians and agricultural chemicals: Review of the risks in a complex environment|journal=Environmental Pollution|year=2009|volume=157|issue=11|pages=2903–2927|doi=10.1016/j.envpol.2009.05.015}}</ref> The half-life of POEA (21–42 days) is longer than that for glyphosate (7–14 days) in aquatic environments.<ref name="Mesnage">{{cite journal | vauthors = Mesnage R, Defarge N, Spiroux de Vendômois J, Séralini GE | title = Potential toxic effects of glyphosate and its commercial formulations below regulatory limits | journal = Food Chem. Toxicol. | volume = 84 | issue = | pages = 133–53 | year = 2015 | pmid = 26282372 | doi = 10.1016/j.fct.2015.08.012 | author-link4 = Gilles-Éric Séralini }}</ref> Aquatic organism exposure risk to terrestrial formulations with POEA is limited to drift or temporary water pockets where concentrations would be much lower than label rates.<ref name="Langeland"/>

Some researchers have suggested the toxicity effects of pesticides on amphibians may be different from those of other aquatic fauna because of their lifestyle; amphibians may be more susceptible to the toxic effects of pesticides because they often prefer to breed in shallow, [[lentic]], or ephemeral pools. These habitats do not necessarily constitute formal water-bodies and can contain higher concentrations of pesticide compared to larger water-bodies.<ref name="Mann" /><ref name="Govindarajulu">{{cite web | vauthors= Govindarajulu PP | year = 2008 | title = Literature Review of Impacts of Glyphosate Herbicide on Amphibians: What Risks can the Silvicultural Use of this Herbicide Pose for Amphibians in BC?|publisher=British Columbia, Ecosystems Branch, Ministry of Environment|accessdate=December 12, 2015|url=http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.314.3577&rep=rep1&type=pdf}}</ref> Studies in a variety of amphibians have shown the toxicity of GBFs containing POEA to amphibian larvae. These effects include interference with gill morphology and mortality from either the loss of osmotic stability or asphyxiation. At sub-lethal concentrations, exposure to POEA or glyphosate/POEA formulations have been associated with delayed development, accelerated development, reduced size at [[metamorphosis]], developmental malformations of the tail, mouth, eye and head, histological indications of intersex and symptoms of oxidative stress.<ref name="Mann" /> Glyphosate-based formulations can cause [[oxidative stress]] in bullfrog tadpoles.<ref name=iarcmono>{{cite web|url=http://monographs.iarc.fr/ENG/Monographs/vol112/mono112-02.pdf|archiveurl=https://web.archive.org/web/20150905094833/http://monographs.iarc.fr/ENG/Monographs/vol112/mono112-02.pdf|archivedate=2015-09-05|title=IARC monograph on glyphosate|publisher=IARC|accessdate=September 27, 2015}}</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>

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 name="ReferenceA">{{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>

====Effect on plant health====
A correlation was found between an increase in the infection rate of wheat by ''[[Fusarium]]'' head blight and the application of glyphosate, but "because of the nature of this study, we could not determine if the association between previous GF (glyphosate formulation) use and FHB development was a cause-effect relationship".<ref name="Fernandeza">{{cite journal |doi=10.2135/cropsci2004.0197 |title=Crop Production Factors Associated with Fusarium Head Blight in Spring Wheat in Eastern Saskatchewan |year=2005 | vauthors = Fernandez MR, Selles F, Gehl D, Depauw RM, Zentner RP | journal = Crop Science | volume = 45 | issue = 5 | pages = 1908–16 }}</ref> Other studies have found causal relationships between glyphosate and decreased disease resistance.<ref>{{cite book |doi=10.1007/978-1-4020-5799-1_15 |chapter=Interactions of Synthetic Herbicides with Plant Disease and Microbial Herbicides |title=Novel Biotechnologies for Biocontrol Agent Enhancement and Management |series=NATO Security through Science Series |year=2007 | vauthors = Duke SO, Wedge DE, Cerdeira AL, Matallo MB | isbn = 978-1-4020-5797-7 | pages = 277–96 | editor1-first = Maurizio | editor1-last = Vurro | editor2-first = Jonathan | editor2-last = Gressel | name-list-format = vanc }}</ref> Exposure to glyphosate has been shown to change the species composition of [[Endophyte|endophytic bacteria]] in plant hosts, which is highly variable.<ref>{{cite journal | vauthors = Rosenblueth M, Martínez-Romero E | title = Bacterial endophytes and their interactions with hosts | journal = Molecular Plant-Microbe Interactions | volume = 19 | issue = 8 | pages = 827–37 | date = Aug 2006 | pmid = 16903349 | doi = 10.1094/MPMI-19-0827 }}</ref>

====Genetic damage====
Several studies have not found [[mutagen|mutagenic effects]],<ref>ToxNet. [http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+3432 Glyposate]. National Library of Medicine.</ref> so glyphosate has not been listed in the [[United States Environmental Protection Agency]] or the [[International Agency for Research on Cancer]] databases.<ref name=Forty>András Székács and Béla Darvas. [http://www.intechopen.com/books/herbicides-properties-synthesis-and-control-of-weeds/forty-years-with-glyphosate Forty years with glyphosate]. In: [http://www.intechopen.com/books/herbicides-properties-synthesis-and-control-of-weeds/forty-years-with-glyphosate Herbicides - Properties, Synthesis and Control of Weeds]", Ed. Mohammed Naguib Abd El-Ghany Hasaneen, {{ISBN|978-953-307-803-8}}, Published: January 13, 2012.</ref> Various other studies suggest glyphosate may be mutagenic.<ref name=Forty /> The IARC monograph noted that glyphosate-based formulations can cause DNA strand breaks in various [[Class (biology)|taxa]] of animals ''in vitro''.<ref name=iarcmono/>


===Regulation===
===Regulation===

Revision as of 15:14, 14 August 2018

This article is about RoundUp and other herbicides. For the chemical compound, see Glyphosate.

Glyphosate herbicides are usually made of a glyphosate salt that is combined with other coformulants that are needed to stabilize the formula and allow penetration into plants.

Background

Monsanto's glyphosate-based herbicide Roundup was first developed in the 1970s. Between 1985 and 1996, Monsanto reduced the price of Roundup by 50%. Between 1990 and 1996 sales of Roundup have increased by around 20% per year.[1] As of 2015 it is used in over 160 countries.[2] Roundup is used most heavily on corn, soy and cotton crops that have been genetically modified to withstand the chemical, but in 2012 glyphosate was used in California to treat other crops like almond, peach, cantaloupe, onion, cherry, sweet corn and citrus.[2]

Monsanto is the largest producer of glyphosate-based herbicides, but formulations from other manufacturers are available that use different inert ingredients.[3] Other glyphosate-based formulations include Bronco, Glifonox, KleenUp, Ranger Pro, Rodeo, Roundup, and Weedoff.[4][5]

Inert ingredients

Glyphosate-based formulations may contain a number of adjuvants, the identities of which are considered trade secrets.[6] Surfactants are used in herbicide formulations as wetting agents, to maximize coverage and aid penetration of the herbicide(s) through plant leaves. As agricultural spray adjuvants, surfactants may be mixed into commercial formulations, such as Roundup, 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 was commonly used in 2015.[7] Different versions of Roundup have included different percentages of POEA. A 1997 US government report said that Roundup is 15% POEA while Roundup Pro is 14.5%.[8] Since POEA is more toxic to fish and amphibians than glyphosate alone, POEA is not allowed in aquatic formulations.[9][8][10][8] 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.[11] This review concluded, "...for terrestrial uses of Roundup minimal acute and chronic risk was predicted for potentially exposed non-target organisms".

Toxicity

Human

Acute toxicity and chronic toxicity are dose-related. Skin exposure to ready-to-use glyphosate formulations can cause irritation, and photocontact dermatitis has been occasionally reported. These effects are probably due to the preservative benzisothiazolin-3-one. Severe skin burns are very rare.[12] Inhalation is a minor route of exposure, but spray mist may cause oral or nasal discomfort, an unpleasant taste in the mouth, or tingling and irritation in the throat. Eye exposure may lead to mild conjunctivitis. Superficial corneal injury is possible if irrigation is delayed or inadequate.[12] Death has been reported after deliberate overdose.[12][13] Ingestion of Roundup ranging from 85 to 200 ml (of 41% solution) has resulted in death within hours of ingestion, although it has also been ingested in quantities as large as 500 ml with only mild or moderate symptoms.[14] Consumption of over 85 ml of concentrated product are likely to cause serious symptoms in adults including burns due to corrosive effects as well as kidney and liver damage. More severe cases cause "respiratory distress, impaired consciousness, pulmonary edema, infiltration on chest X-ray, shock, arrhythmias, renal failure requiring haemodialysis, metabolic acidosis, and hyperkalaemia" and death is often preceded by bradycardia and ventricular arrhythmias.[12]

A 2000 review concluded that "under present and expected conditions of new use, there is no potential for Roundup herbicide to pose a health risk to humans".[15] A 2002 review by the European Union reached the same conclusion.[16]

A 2012 meta-analysis of epidemiological studies (seven cohort studies and fourteen case-control studies) of exposure to glyphosate formulations found no correlation with any kind of cancer.[17] The 2013 systematic review by the German Institute for Risk Assessment of epidemiological studies of workers who use pesticides, exposed to glyphosate formulations found no significant risk, stating that "the available data are contradictory and far from being convincing".[18]: Volume 1, p64-66  However, a 2014 meta-analysis of the same studies found a correlation between occupational exposure to glyphosate formulations and increased risk of B cell lymphoma, the most common kind of non-Hodgkin lymphoma. Workers exposed to glyphosate were about twice as likely to get B cell lymphoma.[19] A 2015 systematic review of observational studies found no evidence that glyphosate exposure among pregnant mothers caused adverse developmental outcomes in their children.[20] A 2016 systematic review and meta-analysis found limited and weak evidence of an association between glyphosate exposure and risk of non-Hodgkin lymphoma and multiple myeloma, while no association was found between glyphosate and risk of other lymphohematopoietic cancers.[21] The same review noted that the positive associations found may be due to bias and confounding.[22]

Aquatic fauna

Glyphosate products for aquatic use generally do not use surfactants, and aquatic formulations do not use POEA due to aquatic organism toxicity.[9][23][24] Due to the presence of POEA, such glyphosate formulations only allowed for terrestrial use are more toxic for amphibians and fish than than glyphosate alone.[9][8][10] The half-life of POEA (21–42 days) is longer than that for glyphosate (7–14 days) in aquatic environments.[25] Aquatic organism exposure risk to terrestrial formulations with POEA is limited to drift or temporary water pockets where concentrations would be much lower than label rates.[9]

Some researchers have suggested the toxicity effects of pesticides on amphibians may be different from those of other aquatic fauna because of their lifestyle; amphibians may be more susceptible to the toxic effects of pesticides because they often prefer to breed in shallow, lentic, or ephemeral pools. These habitats do not necessarily constitute formal water-bodies and can contain higher concentrations of pesticide compared to larger water-bodies.[10][26] Studies in a variety of amphibians have shown the toxicity of GBFs containing POEA to amphibian larvae. These effects include interference with gill morphology and mortality from either the loss of osmotic stability or asphyxiation. At sub-lethal concentrations, exposure to POEA or glyphosate/POEA formulations have been associated with delayed development, accelerated development, reduced size at metamorphosis, developmental malformations of the tail, mouth, eye and head, histological indications of intersex and symptoms of oxidative stress.[10] Glyphosate-based formulations can cause oxidative stress in bullfrog tadpoles.[27]

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."[28]

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.[29]

Effect on plant health

A correlation was found between an increase in the infection rate of wheat by Fusarium head blight and the application of glyphosate, but "because of the nature of this study, we could not determine if the association between previous GF (glyphosate formulation) use and FHB development was a cause-effect relationship".[30] Other studies have found causal relationships between glyphosate and decreased disease resistance.[31] Exposure to glyphosate has been shown to change the species composition of endophytic bacteria in plant hosts, which is highly variable.[32]

Genetic damage

Several studies have not found mutagenic effects,[33] so glyphosate has not been listed in the United States Environmental Protection Agency or the International Agency for Research on Cancer databases.[34] Various other studies suggest glyphosate may be mutagenic.[34] The IARC monograph noted that glyphosate-based formulations can cause DNA strand breaks in various taxa of animals in vitro.[27]

Regulation

In the European Union the active ingredient, glyphosate, is approved at the supranational EU level and is governed by Regulation No 1107/2009. Specific glyphosate-based formulations, like Roundup, are regulated at the Member State level. There are about 30 different glyphosate-based formulations used in Estonia.[5]

As part of the process to renew glyphosate's license under EU regulations, the European Food Safety Authority (EFSA) published a final risk assessment on 12 November 2015 stating that glyphosate met EU-level regulatory standards. Despite classifying glyphosate as non-carcinogenic, this report also acknowledged that some of the co-formulants added to glyphosate based pesticides "appeared to have toxic effects higher than the glyphosate itself", noting POEA in particular. The conclusion of the final EFSA assessment was that glyphosate met EU-level regulatory standards, but individual formulations would have to be evaluated by member states.[35]

References

  1. ^ "Top-selling herbicide not close to withering". Wall Street Journal. 1996-01-08. Retrieved 2018-08-12.
  2. ^ a b "What Do We Really Know About Roundup Weed Killer?". National Geographic News. 2015-04-23. Retrieved 2018-08-13.
  3. ^ News, Crystal Gammon, Environmental Health. "Weed-Whacking Herbicide Proves Deadly to Human Cells". Scientific American. Retrieved 2018-08-12. {{cite web}}: |last= has generic name (help)CS1 maint: multiple names: authors list (link)
  4. ^ Vaida, Bara. "Does This Common Pesticide Cause Cancer?". WebMD. Retrieved 2018-08-13.
  5. ^ a b Sihtmäe, M.; Blinova, I.; Künnis-Beres, K.; Kanarbik, L.; Heinlaan, M.; Kahru, A. (2013-10-01). "Ecotoxicological effects of different glyphosate formulations". Applied Soil Ecology. 72: 215–224. doi:10.1016/j.apsoil.2013.07.005. ISSN 0929-1393. Retrieved 2018-08-13.
  6. ^ "Pesticide Registration Manual | Pesticide Registration | US EPA".
  7. ^ "Measuring POEA, a Surfactant Mixture in Herbicide Formulations". U.S. Geological Survey.
  8. ^ a b c d Gary L. Diamond and Patrick R. Durkin February 6, 1997, under contract from the United States Department of Agriculture. Effects of Surfactants on the Toxicity of Glyphosate, with Specific Reference to RODEO
  9. ^ a b c d "SS-AGR-104 Safe Use of Glyphosate-Containing Products in Aquatic and Upland Natural Areas" (PDF). University of Florida. Retrieved 13 August 2018.
  10. ^ a b c d Mann RM, Hyne RV, Choung CB, Wilson SP (2009). "Amphibians and agricultural chemicals: Review of the risks in a complex environment". Environmental Pollution. 157 (11): 2903–2927. doi:10.1016/j.envpol.2009.05.015.
  11. ^ Giesy JP, Dobson S, Solomon KR (2000). "Ecotoxicological risk assessment for Roundup® herbicide". Reviews of Environmental Contamination and Toxicology. Reviews of Environmental Contamination and Toxicology. 167: 35–120. doi:10.1007/978-1-4612-1156-3_2. ISBN 978-0-387-95102-7.
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