Editing Herbicide (section)

===Human health===
Many questions exist about herbicides' health and environmental effects, because of the many kinds of herbicide and the myriad potential targets, mostly unintended. For example, a 1995 panel of 13 scientists reviewing studies on the [[carcinogenicity]] of [[2,4-Dichlorophenoxyacetic acid|2,4-D]] had divided opinions on the likelihood 2,4-D causes [[cancer]] in humans.<ref>{{cite journal |vauthors=Ibrahim MA, Bond GG, Burke TA, Cole P, Dost FN, Enterline PE, Gough M, Greenberg RS, Halperin WE, McConnell E | title = Weight of the evidence on the human carcinogenicity of 2,4-D | journal = Environ Health Perspect | year = 1991 | volume = 96 | pages = 213–222 | pmid = 1820267 | pmc = 1568222 | doi=10.1289/ehp.9196213| bibcode = 1991EnvHP..96..213I |display-authors=etal}}</ref> {{As of|1992}}, studies on [[phenoxy herbicide]]s were too few to accurately assess the risk of many types of cancer from these herbicides, even although evidence was stronger that exposure to these herbicides is associated with increased risk of [[soft tissue sarcoma]] and [[non-Hodgkin lymphoma]].<ref name="jnci">{{cite journal |author1=Howard I. Morrison |author2=Kathryn Wilkins |author3=Robert Semenciw |author4=Yang Mao |author5=Don Wigle | title = Herbicides and Cancer | journal = [[Journal of the National Cancer Institute]] | volume = 84 | issue = 24 | pages = 1866–1874 | year = 1992 | doi = 10.1093/jnci/84.24.1866 | pmid = 1460670| doi-access = free }}</ref>

'''Toxicity'''

Herbicides have widely variable [[toxicity]]. [[Acute toxicity]], short term exposure effects, and [[chronic toxicity]], from long term environmental or occupational exposure. Much public suspicion of herbicides confuses valid statements of ''acute'' toxicity with equally valid statements of lack of ''chronic'' toxicity at the recommended levels of usage. For instance, while glyphosate formulations with tallowamine ''adjuvants'' are acutely toxic, their use was found to be uncorrelated with any health issues like cancer in a massive US Department of Health study on 90,000 members of farmer families for over a period of 23 years.<ref>{{cite journal |doi=10.1093/jnci/djx233|pmid=29136183|pmc=6279255|title=Glyphosate Use and Cancer Incidence in the Agricultural Health Study|journal=JNCI Journal of the National Cancer Institute|volume=110|issue=5|pages=509–516|year=2018|last1=Andreotti|first1=Gabriella|last2=Koutros|first2=Stella|last3=Hofmann|first3=Jonathan N|last4=Sandler|first4=Dale P|last5=Lubin|first5=Jay H|last6=Lynch|first6=Charles F|last7=Lerro|first7=Catherine C|last8=De Roos|first8=Anneclaire J|last9=Parks|first9=Christine G|last10=Alavanja|first10=Michael C|last11=Silverman|first11=Debra T|last12=Beane Freeman|first12=Laura E}}</ref> That is, the study shows lack of chronic toxicity, but cannot question the herbicide's acute toxicity.

'''Health effects'''

Some herbicides cause a range of health effects ranging from skin rashes to death. The pathway of attack can arise from intentional or unintentional direct consumption, improper application resulting in the herbicide coming into direct contact with people or wildlife, inhalation of aerial sprays, or food consumption prior to the labelled preharvest interval. Under some conditions, certain herbicides can be transported via [[Leaching (agriculture)|leaching]] or [[surface runoff]] to contaminate groundwater or distant surface water sources. Generally, the conditions that promote herbicide transport include intense storm events (particularly shortly after application) and soils with limited capacity to [[adsorb]] or retain the herbicides. Herbicide properties that increase likelihood of transport include persistence (resistance to degradation) and high water solubility.<ref name="Smith1995">{{cite book|author=Smith|title=Handbook of Weed Management Systems|chapter-url=https://books.google.com/books?id=bTDFaJfOBm8C&pg=PA245|date=18 July 1995|publisher=CRC Press|isbn=978-0-8247-9547-4|pages=245–278|chapter=8: Fate of herbicides in the environment}}</ref>

'''Contamination'''

Cases have been reported where [[Phenoxy herbicides]] are contaminated with [[Dioxins and dioxin-like compounds|dioxins]] such as [[2,3,7,8-Tetrachlorodibenzodioxin|TCDD]];<ref>{{Cite web|url=http://www.publichealth.va.gov/exposures/agentorange/basics.asp|title=Facts About Herbicide - Department Of Veterans Affairs|access-date=September 1, 2016}}</ref>{{Citation needed|date=January 2015}} research has suggested such contamination results in a small rise in cancer risk after occupational exposure to these herbicides.<ref>{{cite journal | pmid = 9199536 | year = 1997 |display-authors= 3| last1 = Kogevinas | first1 = M | last2 = Becher | first2 = H | last3 = Benn | first3 = T | last4 = Bertazzi | first4 = PA | last5 = Boffetta | first5 = P | last6 = Bueno-De-Mesquita | first6 = HB | last7 = Coggon | first7 = D | last8 = Colin | first8 = D | last9 = Flesch-Janys | first9 = D | title = Cancer mortality in workers exposed to phenoxy herbicides, chlorophenols, and dioxins. An expanded and updated international cohort study | volume = 145 | issue = 12 | pages = 1061–75 | journal = American Journal of Epidemiology | doi = 10.1093/oxfordjournals.aje.a009069| doi-access = free }}</ref> [[Triazine]] exposure has been implicated in a likely relationship to increased risk of [[breast cancer]], although a [[causal]] relationship remains unclear.<ref>{{cite journal | pmid = 9370519 | year = 1997 | last1 = Kettles | first1 = MK | last2 = Browning | first2 = SR | last3 = Prince | first3 = TS | last4 = Horstman | first4 = SW | title = Triazine herbicide exposure and breast cancer incidence: An ecologic study of Kentucky counties | volume = 105 | issue = 11 | pages = 1222–7 | pmc = 1470339 | journal = Environmental Health Perspectives | doi = 10.1289/ehp.971051222| bibcode = 1997EnvHP.105.1222K }}</ref>

'''False claims'''

Herbicide manufacturers have at times made false or misleading claims about the safety of their products. Chemical manufacturer [[Monsanto Company]] agreed to change its advertising after pressure from New York attorney general [[Dennis Vacco]]; Vacco complained about misleading claims that its spray-on glyphosate-based herbicides, including Roundup, were safer than table salt and "practically non-toxic" to mammals, birds, and fish (though proof that this was ever said is hard to find).<ref>{{cite news | title = Monsanto Pulls Roundup Advertising in New York | newspaper = Wichita Eagle | date = Nov 27, 1996}}</ref> Roundup is toxic and has resulted in [[death]] after being ingested in quantities ranging from 85 to 200 ml, although it has also been ingested in quantities as large as 500 ml with only mild or moderate symptoms.<ref>{{cite journal | pmid = 1673618 | year = 1991 | last1 = Talbot | first1 = AR | last2 = Shiaw | first2 = MH | last3 = Huang | first3 = JS | last4 = Yang | first4 = SF | last5 = Goo | first5 = TS | last6 = Wang | first6 = SH | last7 = Chen | first7 = CL | last8 = Sanford | first8 = TR | title = Acute poisoning with a glyphosate-surfactant herbicide ('Roundup'): A review of 93 cases | volume = 10 | issue = 1 | pages = 1–8 | journal = Human & Experimental Toxicology | doi = 10.1177/096032719101000101| bibcode = 1991HETox..10....1T | s2cid = 8028945 }}</ref> The manufacturer of [[Tordon 101]] ([[Dow AgroSciences]], owned by the [[Dow Chemical Company]]) has claimed Tordon 101 has no effects on animals and insects,<ref>{{cite news | url = https://www.cbc.ca/news/canada/nova-scotia/complaints-halt-herbicide-spraying-in-eastern-shore-1.833985 | title = Complaints halt herbicide spraying in Eastern Shore | publisher = CBC News | date = June 16, 2009}}</ref> in spite of evidence of strong carcinogenic activity of the active ingredient,<ref>{{Cite web |url=http://www.omafra.gov.on.ca/english/crops/facts/notes/picloram2.htm |title=Tordon 101: picloram/2,4-D |work=Ontario Ministry of Agriculture Food & Rural Affairs|archive-url=https://web.archive.org/web/20100312025508/http://www.omafra.gov.on.ca/english/crops/facts/notes/picloram2.htm |archive-date=2010-03-12 }}</ref> [[picloram]], in studies on rats.<ref>{{cite journal | author = Reuber, MD | title = Carcinogenicity of Picloram | journal = Journal of Toxicology and Environmental Health | volume = 7 | issue = 2 | pages = 207–222 | year = 1981 | doi = 10.1080/15287398109529973 | pmid = 7014921| bibcode = 1981JTEH....7..207R }}</ref>