Agent Green

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Ranch Hand UC-123B spraying defoliant in 1962 UC-123B Ranch Hand spraying 1962.jpg
Ranch Hand UC-123B spraying defoliant in 1962

Agent Green is the code name for a powerful herbicide and defoliant used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the green stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "Rainbow Herbicides". Agent Green was only used between 1962 and 1964, during the early "testing" stages of the spraying program.

Herbicide Chemical used to kill unwanted plants

Herbicides, also commonly known as weedkillers, are substances used to control unwanted plants. Selective herbicides control specific weed species, while leaving the desired crop relatively unharmed, while non-selective herbicides can be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact. Apart from selective/non-selective, other important distinctions include persistence, means of uptake, and mechanism of action. Historically, products such as common salt and other metal salts were used as herbicides, however these have gradually fallen out of favor and in some countries a number of these are banned due to their persistence in soil, and toxicity and groundwater contamination concerns. Herbicides have also been used in warfare and conflict.

Defoliant Chemical sprayed or dusted on plants to cause its leaves to fall off

A defoliant is any herbicidal chemical sprayed or dusted on plants to cause their leaves to fall off. Defoliants are widely used for the selective removal of weeds in managing croplands and lawns. Worldwide use of defoliants, along with the development of other herbicides and pesticides, allowed for the Green Revolution, an increase in agricultural production in mid-20th century. Defoliants have also been used in warfare as a means to deprive an enemy of food crops and/or hiding cover, most notably by the United States in the Vietnam War.

Herbicidal warfare

Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an area. Although herbicidal warfare use chemical substances, its main purpose is to disrupt agricultural food production and/or to destroy plants which provide cover or concealment to the enemy, not to asphyxiate or poison humans and/or destroy human-made structures. Herbicidal warfare has been forbidden by the Environmental Modification Convention since 1978, which bans "any technique for changing the composition or structure of the Earth's biota".

Agent Green was mixed with Agent Pink and used for crop destruction. A total of 20,000 gallons of Agent Green were procured. [1]

Agent Pink A Herbicide in Rainbow herbicides

Agent Pink is the code name for a powerful herbicide and defoliant used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the pink stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the rainbow herbicides that included the more infamous Agent Orange. Agent Pink was only used during the early "testing" stages of the spraying program before 1964.

Agent Green's only active ingredient was 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), one of the common phenoxy herbicides of the era. Even prior to Operation Ranch Hand (1962-1971) it was known [2] [3] [4] [5] [6] [7] that a dioxin, 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD), is produced as a side product of the manufacture of 2,4,5-T, and was thus present in any of the herbicides that used it. Because Agent Green's only active ingredient was 2,4,5-T, along with the similar Agent Pink, and earlier-produced batches of 2,4,5-T having higher TCDD-levels, [8] it contained many times the average level of dioxin found in Agent Orange.

Phenoxy herbicide class of herbicide

Phenoxy herbicides are a family of chemicals related to the growth hormone indoleacetic acid (IAA). When sprayed on broad-leaf plants they induce rapid, uncontrolled growth. When sprayed on monocotyledonous (grass) crops such as wheat or corn, they selectively kill broad-leaf weeds, leaving the crops relatively unaffected. The wide variety of phenoxies in use today can be grouped into the phenoxyacetic, phenoxybutyric and phenoxypropionic subtypes, the latter containing the aryloxyphenoxypropionic subtype with the greatest number of commercial variants. Chemically, they are carboxylic acids, typically applied in an ester or salt form.

Operation Ranch Hand U.S. military herbicidal warfare operation during the Vietnam War

Operation Ranch Hand was a U.S. military operation during the Vietnam War, lasting from 1962 until 1971. Largely inspired by the British use of 2,4,5-T and 2,4-D during the Malayan Emergency in the 1950s, it was part of the overall herbicidal warfare program during the war called "Operation Trail Dust". Ranch Hand involved spraying an estimated 20 million U.S. gallons (76,000 m3) of defoliants and herbicides over rural areas of South Vietnam in an attempt to deprive the Viet Cong of food and vegetation cover. Areas of Laos and Cambodia were also sprayed to a lesser extent. Nearly 20,000 sorties were flown between 1961 and 1971.

Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of polyhalogenated organic compounds that are significant environmental pollutants.

During much of the fighting in the Vietnam War, chemical agents were used by the United States to defoliate the landscape. Although many different chemical agents were used, the most well known today is "Agent Orange," one of the "Rainbow Herbicides"

Agent Orange military herbicide

Agent Orange is a herbicide and defoliant chemical, one of the "tactical use" Rainbow Herbicides. It is widely known for its use by the U.S. military as part of its herbicidal warfare program, Operation Ranch Hand, during the Vietnam War from 1961 to 1971. It is a mixture of equal parts of two herbicides, 2,4,5-T and 2,4-D. In addition to its damaging environmental effects, traces of dioxin found in the mixture have caused major health problems for many individuals who were exposed.

The Rainbow Herbicides are a group of "tactical use" chemicals used by the United States military in Southeast Asia during the Vietnam War. Success with Project AGILE field tests with herbicides in South Vietnam in 1961 and inspiration by the British use of herbicides and defoliants during the Malayan Emergency in the 1950s led to the formal herbicidal program Trail Dust. Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an agricultural food production and/or to destroy foliage which provides the enemy cover.

Related Research Articles

The Seveso disaster was an industrial accident that occurred around 12:37 pm on July 10, 1976, in a small chemical manufacturing plant approximately 20 kilometres (12 mi) north of Milan in the Lombardy region of Italy. It resulted in the highest known exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in residential populations, which gave rise to numerous scientific studies and standardized industrial safety regulations. The EU industrial safety regulations are known as the Seveso II Directive.

Chloracne skin disease caused by chlorinated organic compounds

Chloracne is an acne-like eruption of blackheads, cysts, and pustules associated with over-exposure to certain halogenated aromatic compounds, such as chlorinated dioxins and dibenzofurans. The lesions are most frequently found on the cheeks, behind the ears, in the armpits and groin region.

Agent Purple A Herbicide in Rainbow herbicides

Agent Purple is the code name for a powerful herbicide and defoliant used by the U.S. military in their herbicidal warfare program during the Vietnam War. The name comes from the purple stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "Rainbow Herbicides" that included the more infamous Agent Orange. Agent Purple and Orange were also used to clear brush in Canada.

Agent White A Herbicide in Rainbow herbicides

Agent White is the code name for a herbicide used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the regulatory requirements of identifying each container of the various herbicides through the addition of colored stripes. Orange, Purple, Blue, and White were colors used by the manufacturers to ensure that the contents were easily identifiable in shipment and use. Colors were selected by the U.S. Government. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "rainbow herbicides".

2,4,5-Trichlorophenoxyacetic acid chemical compound

2,4,5-Trichlorophenoxyacetic acid, a synthetic auxin, is a chlorophenoxy acetic acid herbicide used to defoliate broad-leafed plants. It was developed in the late 1940s and was widely used in the agricultural industry until being phased out, starting in the late 1970s due to toxicity concerns. Agent Orange, a defoliant used by the British in the Malayan Emergency and the U.S. in the Vietnam War, was equal parts 2,4,5-T and 2,4-D. 2,4,5-T itself is toxic with a NOAEL of 3 mg/kg/day and a LOAEL of 10 mg/kg/day. Additionally, the manufacturing process for 2,4,5-T contaminates this chemical with trace amounts of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD is a carcinogenic persistent organic pollutant with long-term effects on the environment. With proper temperature control during production of 2,4,5-T, TCDD levels can be held to about .005 ppm. Before the TCDD risk was well understood, early production facilities lacked proper temperature controls and individual batches tested later were found to have as much as 60 ppm of TCDD.

1,4-Dioxin heterocyclic, organic, antiaromatic compound

1,4-Dioxin (also referred as dioxin or p-dioxin) is a heterocyclic, organic, non-aromatic compound with the chemical formula C4H4O2. There is an isomeric form of 1,4-dioxin, 1,2-dioxin (or o-dioxin). 1,2-Dioxin is very unstable due to its peroxide-like characteristics.

Dioxins and dioxin-like compounds class of chemical compounds

Dioxins and dioxin-like compounds (DLCs) are compounds that are highly toxic environmental persistent organic pollutants (POPs). They are mostly by-products of various industrial processes - or, in case of dioxin-like PCBs and PBBs, part of intentionally produced mixtures. They include:

Gagetown is a 2009 documentary film that looks into the massive defoliant spray program that was used at CFB Gagetown since 1956. The chemical herbicides used include 50/50 mixtures of 2,4-D/ 2,4,5-T, and Tordon 101, also known as Agent Orange and Agent White.

2,3,7,8-Tetrachlorodibenzodioxin chemical compound

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a polychlorinated dibenzo-p-dioxin with the chemical formula C
12H
4Cl
4O
2. Pure TCDD is a colorless solid with no distinguishable odor at room temperature. It is usually formed as a side product in organic synthesis and burning of organic materials.

The Enlist Weed Control System is an agricultural system that includes seeds for genetically modified crops that are resistant to Enlist and the Enlist herbicide; spraying the herbicide will kill weeds but not the resulting crop. The system was developed by Dow AgroSciences, part of Dow Chemical Company. In October 2014 the system was registered for restricted use in Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin by the US Environmental Protection Agency. In 2013, the system was approved by Canada for the same uses.

Agent Orange Act of 1991

Agent Orange Act of 1991 establishes provisions for the National Academy of Sciences to analyze and summarize scientific evidence regarding presumptive military service exposure to defoliants, dioxins and herbicides, better known as Agent Orange, during the Vietnam War era. The United States Statute endorses an observation of human medical conditions directly related to non-Hodgkin lymphoma, soft-tissue sarcoma, chloracne, and consistent acneform diseases for military personnel who served in the overseas Vietnamese region. The Act of Congress ratifies a medical research compilation of voluntarily contributed blood and tissue samples provided by Vietnam-era veterans serving in Southeast Asia between 1961 and 1975.

Agent Orange is a chemical weapon most notably used by the U.S. Military during the Vietnam War, classified as defoliant. Its primary purpose was strategic deforestation, destroying the forest cover and food resources necessary for the implementation and sustainability of the North Vietnamese style of guerilla warfare. The U.S. Agent Orange usage reached an apex during Operation Ranch Hand, in which the material was sprayed over 4.5 million acres of land in Vietnam from 1961 to 1971.

References

  1. ↑ Young Alvin. The History, Use, Disposition and Environmental Fate of Agent Orange. Springer. 2009. pg. 174
  2. ↑ Berufliche Akne (sog. Chlorakne) durch chlorierte aromatische zyklische Äther Von J. Kimmig und K. H. Schulz in Dermatologica Vol. 115, 1957, p.540-6 (German; with English and French summaries; cited in CA 1958:22227) (accessed 2013-07-29)
  3. ↑ Table TCDD-UNFÄLLE - Eine Bilanz des Schreckens pp. 54-59 in Seveso ist überall - Die tödlichen Risiken der Chemie by Egmont R. Koch, Fritz Vahrenholt; 1978, ISBN   3 462 012908 (accessed 2013-07-29)
  4. ↑ p. 49 in Seveso ist überall - Die tödlichen Risiken der Chemie by Egmont R. Koch, Fritz Vahrenholt; 1978, ISBN   3 462 012908
  5. ↑ Peter H. Schuck: Agent Orange on Trial: Mass Toxic Disasters in the Courts p. 17 (accessed 2013-07-29)
  6. ↑ "Chemical companies, US authorities knew dangers of Agent Orange" Archived 2016-08-22 at the Wayback Machine by Jon Dillingham; August 10, 2009 (accessed 2013-07-29)
  7. ↑ REPORT TO SECRETARY OF THE DEPARTMENT OF VETERANS AFFAIRS ON THE ASSOCIATION BETWEEN ADVERSE HEALTH EFFECTS AND EXPOSURE TO AGENT ORANGE Archived 2016-04-06 at the Wayback Machine as Reported by Special Assistant Admiral E.R. Zumwalt, Jr., May 5, 1990 (accessed 2013-07-29)
  8. ↑ Stellman, Jeanne et al. The Extent and patterns of usage of Agent Orange and other herbicides in Vietnam Nature, Vol. 422 (17 April 2003) pp. 681-687 (accessed 2013-07-28)
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