roundup

This article is about the herbicidal formulation. For information on the herbicidal main active ingredient, see glyphosate. For other uses, see Round Up (disambiguation).

Roundup is the brand name of a systemic, broad-spectrum herbicide produced by the U.S. company Monsanto and contains the active ingredient glyphosate. Glyphosate is the most used herbicide in the USA ^[1], and Roundup is the number one selling herbicide worldwide since at least 1980.^[2]

Monsanto developed and patented the glyphosate molecule in the 1970s, and marketed Roundup from 1973. It retained exclusive rights in the US until its US patent expired in September, 2000, and maintained a predominant marketshare in countries where the patent expired earlier.

The main active ingredient of Roundup is the isopropylamine salt of Glyphosate.

Monsanto also produces seeds which grow into plants genetically engineered to be tolerant to glyphosate which are known as Roundup Ready crops. The genes contained in these seeds are patented. Such crops allow farmers to use glyphosate as a post-emergence herbicide against both broadleaf and cereal weeds. Soy was the first Roundup Ready crop and was produced at Monsanto's Agracetus Campus located in Middleton, Wisconsin.

Health, ecological concerns and controversy

Roundup commercial formulations were never submitted to test by the United States Environmental Protection Agency‎ (EPA), its main active ingredient, glyphosate, received EPA Toxicity Class of III for oral and inhalation exposure.^[3]

Beyond the glyphosate salts content, commercial formulations of Roundup contain surfactants, which vary in nature and concentration. As a result, human poisoning with this herbicide is not with the main active ingredient alone but with complex and variable mixtures. ^[4]

Human and mammalian toxicity

In 2000, a review of the available literature concluded that "under present and expected conditions of new use, there is no potential for Roundup herbicide to pose a health risk to humans".^[5]

Another review concluded that "for terrestrial uses of Roundup minimal acute and chronic risk was predicted for potentially exposed nontarget organisms"^[6] while also noting that there were some risks to aquatic organisms exposed to Roundup in shallow water. It is because of this fact that roundup is not registered for use in aquatic envrionments. In later mammalian research, Roundup has been found to interfere with an enzyme involved in testosterone production in mouse cell culture^[7] and to interfere with an estrogen biosynthesis enzyme in cultures of Human Placental cells.^[8]

A 2008 scientific study has shown that Roundup formulations and metabolic products cause the death of human embryonic, placental, and umbilical cells in vitro even at low concentrations. The effects were not proportional to the main active ingredient concentrations (glyphosate) but dependent on the nature of the adjuvants used in the Roundup formulation.^[9]

Opponents of Roundup claim that it has been found to cause genetic damage, citing Peluso et al.^[10] The authors concluded that the damage was "not related to the active ingredient, but to another component of the herbicide mixture".

Ingestion of Roundup in quantities ranging from 85-200 ml has resulted in death, although it has also been ingested in quantities as large as 500ml with only mild or moderate symptoms.^[11] There is a reasonable correlation between the amount of Roundup ingested and the likelihood of serious systemic sequelae or death. Ingestion of >85 mL of the concentrated formulation is likely to cause significant toxicity in adults. Gastrointestinal corrosive effects, with mouth, throat and epigastric pain and dysphagia are common. Renal and hepatic impairment are also frequent and usually reflect reduced organ perfusion. Respiratory distress, impaired consciousness, pulmonary oedema, infiltration on chest x-ray, shock, arrythmias, renal failure requiring haemodialysis, metabolic acidosis and hyperkalaemia may supervene in severe cases. Bradycardia and ventricular arrhythmias are often present pre-terminally. Dermal exposure to ready-to-use glyphosate formulations can cause irritation and photo-contact dermatitis has been reported occasionally; these effects are probably due to the preservative Proxel (benzisothiazolin-3-one). Severe skin burns are very rare. Inhalation is a minor route of exposure but spray mist may cause oral or nasal discomfort, an unpleasant taste in the mouth, tingling and throat irritation. Eye exposure may lead to mild conjunctivitis, and superficial corneal injury is possible if irrigation is delayed or inadequate. ^[4]

False advertising

In 1996 Monsanto was accused of false and misleading advertising of glyphosate products, prompting a law suit by the New York State attorney general.^[12] Monsanto had made claims that its spray-on glyphosate based herbicides, including Roundup, were safer than table salt and "practically non-toxic" to mammals, birds, and fish.^[13]

Environmental and consumer rights campaigners brought a case in France in 2001 for presenting Roundup as biodegradable and claiming that it left the soil clean after use; glyphosate, Roundup's main ingredient, is classed by the European Union as "dangerous for the environment" and "toxic for aquatic organisms". In January 2007, Monsanto was convicted of false advertising.^[14]

Scientific fraud

On two occasions the United States Environmental Protection Agency has caught scientists deliberately falsifying test results at research laboratories hired by Monsanto to study glyphosate.^[15][16][17] In the first incident involving Industrial Biotest Laboratories, an EPA reviewer stated after finding "routine falsification of data" that it was "hard to believe the scientific integrity of the studies when they said they took specimens of the uterus from male rabbits".^[18][19][20] In the second incident of falsifying test results in 1991, the owner of the lab (Craven Labs), and three employees were indicted on 20 felony counts, the owner was sentenced to 5 years in prison and fined 50,000 dollars, the lab was fined 15.5 million dollars and ordered to pay 3.7 million in restitution.^[21][22][23] Craven laboratories performed studies for 262 pesticide companies including Monsanto.

Monsanto has stated that the studies have been repeated and that Roundup's EPA certification does not now use any studies from Craven Labs or IBT. Monsanto also claims that the Craven Labs investigation was started by the EPA after a pesticide industry task force discovered irregularities.^[24]

Aquatic effects

Fish and aquatic invertebrates are more sensitive to Roundup than terrestrial organisms.^[6] Glyphosate is generally less persistent in water than in soil, with 12 to 60 day persistence observed in Canadian pond water, yet persistence of over a year have been observed in the sediments of ponds in Michigan and Oregon.^[3]
The EU classifies Roundup as R51/53 Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment.^[25]

Although Roundup is not registered for aquatic uses^[26] and studies of its effects on amphibians indicate it is toxic to them,^[27] scientists have found that it may wind up in small wetlands where tadpoles live due to inadvertent spraying during its application. A recent study found that even at concentrations one-third of the maximum concentrations expected in nature, Roundup still killed up to 71 percent of tadpoles raised in outdoor tanks.^[28]

Environmental degradation and effects

When glyphosate comes into contact with the soil it can be rapidly bound to soil particles and be inactivated.^[3] Unbound glyphosate can be degraded by bacteria.^[29] Glyphosphate has been shown to increase the infection rate of wheat by fusarium head blight in fields that have been treated with glyphosphate. ^[30]

In soils, half lives vary from as little as 3 days at a site in Texas, 141 days at a site in Iowa, to between 1–3 years in Swedish forest soils.^[23] It appears that higher latitude sites have the longest soil persistences such as in Canada and Scandinavia.

A recent study concluded that certain amphibians may be at risk from glyphosate use.^[31] One study has shown an effect on growth and survival of earthworms.^[32] The results of this study are in conflict with other data and have been criticized on methodological grounds.^[6] In other studies nitrogen fixing bacteria have been impaired, and also crop plant susceptibility to disease has been increased.^{[30][33][34][35][36][37][38]}

Endocrine disruptor debate

An in-vitro study^[39] has suggested glyphosate may have an effect on progesterone production in mammalian cells and affect mortality of placental cells in-vitro.^[8] Whether these studies classify glyphosate as an endocrine disruptor is a matter of debate.

Some believe that in-vitro studies are insufficient, and are waiting to see if animal studies show a change in endocrine activity, since a change in a single cell line may not occur in an entire organism.^{[citation needed]} Additionally, current in-vitro studies expose cell lines to concentrations orders of magnitude greater than would be found in real conditions, and through pathways that would not be experienced in real organism.^{[citation needed]}

Others believe that in-vitro studies, particularly ones identifying not only an effect, but a chemical pathway, are sufficient evidence to classify Roundup as an endocrine disruptor, on the basis that even small changes in endocrine activity can have lasting effects on an entire organism that may be difficult to detect through whole organism studies alone.^{[citation needed]}

Glyphosate resistance in weeds and microorganisms

Resistance evolves after a weed population has been subjected to intense selection pressure in the form of repeated use of a single herbicide.^[40] These weeds resistant to the herbicide have been called "Superweeds".^[41][42]

The first documented cases of weed resistance to glyphosate were found in Australia, involving rigid ryegrass near Orange, New South Wales.^[43] Some farmers in the United States have expressed concern that weeds are now developing with glyphosate resistance, with 13 states now reporting resistance, and this poses a problem to many farmers, including cotton farmers, that are now heavily dependent on glyphosate to control weeds.^[44][45] Farmers associations are now reporting 103 biotypes of weeds within 63 weed species with herbicide resistance^[44][45]. This problem is likely to be exacerbated by the use of roundup-ready crops ^[46]. Fifteen weed species have been confirmed as resistant to glyphosate.^[40]

Some microorganisms have a version of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS: EC 2.5.1.19, 3-phosphoshikimate 1-carboxyvinyltransferase; 5-enolpyruvylshikimate-3-phosphate synthetase; phosphoenolpyruvate:3-phosphoshikimate 5-O-(1-carboxyvinyl)-transferase) that is resistant to glyphosate inhibition. The version used in genetically modified crops was isolated from Agrobacterium strain CP4 (CP4 EPSPS) that was resistant to glyphosate.^[47][48] The CP4 EPSPS gene was cloned and inserted into soybeans. The CP4 EPSPS gene was engineered for plant expression by fusing the 5' end of the gene to a chloroplast transit peptide derived from the petunia EPSPS. This transit peptide was used because it had shown previously an ability to deliver bacterial EPSPS to the chloroplasts of other plants. The plasmid used to move the gene into soybeans was PV-GMGTO4. It contained three bacterial genes, two CP4 EPSPS genes, and a gene encoding beta-glucuronidase (GUS) from Escherichia coli as a marker. The DNA was injected into the soybeans using the particle acceleration method. Soybean cultivar A54O3 was used for the transformation. The expression of the GUS gene was used as the initial evidence of transformation. GUS expression was detected by a staining method in which the GUS enzyme converts a substrate into a blue precipitate. Those plants that showed GUS expression were then taken and sprayed with glyphosate and their tolerance was tested over many generations.

Genetically modified crops

In 1996, genetically modified Roundup Ready soybeans resistant to Roundup became commercially available, followed by Roundup Ready corn in 1998.^[49] Current Roundup Ready crops include soy, maize (corn), canola^[50], sugar beet^[51] and cotton, with wheat^[52] and alfalfa^[53] still under development. These cultivars greatly improved conventional farmers' ability to control weeds since glyphosate could be sprayed on fields without hurting the crop. As of 2005, 87% of U.S. soybean fields were planted to glyphosate resistant varieties.^[54][55] While the use of roundup ready crops may have increased the usage of herbicides measured in pounds applied per acre.^[56] The use of Roundup Ready crops has changed the herbicide use profile away from atrazine, metribuzin, and alachlor. This has the benefit of reducing the dangers of herbicide run off into drinking water.^[57]

In 1999, a review of Roundup Ready soybean crops found that, compared to the top conventional varieties, they had a 6.7% lower yield^[56]. This so called "yield drag" follows the same pattern observed when other traits are introduced into soybeans by conventional breeding. ^[58] Monsanto claims later patented varieties yield 7-11% higher than their poorly performing initial varieties, closer to those of conventional farming, although the company refrains from citing actual yields ^[59].

Monsanto has received criticism for trying to prevent farmers from saving and replanting seeds, accusing farmers of patent infringement even when such practices clearly fall under the exhaustion doctrine and the third exemption of the Plant Variety Protection Act.^[60][61] The practice of patenting living things is in itself also subject to much debate^[62] because Monsanto has patented MON-89788-1^[63] (RR 2) which was only created through the insertion of the naturally-occurring gene for the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) isolated from the soil bacterium Agrobacterium tumefaciens into soybeans. Monsanto is also developing genetic modifications into crops so that the resultant plants are incapable of reproducing, and seed can't be harvested, and also completely destroying biological self-sufficiency.^[64][65]

Tradenames

The Roundup trademark is registered with the US Patent Office and still extant. However, the chemical formulation is no longer under patent, so similar products using glyphosate as the active ingredient are available from other manufacturers and marketed under many names,^[66] including Buccaneer, Razor Pro, (41%), Rodeo (51.2%), Aquaneat (53.8%), and Aquamaster (53.5%)^[67]

Other uses

Glyphosate is one of a number of herbicides used by the United States government to spray Colombian coca fields through Plan Colombia. There are reports that widespread application of glyphosate in attempts to destroy coca crops in South America have resulted in the development of glyphosate-resistant strains of coca known as Boliviana negra, which have been selectively bred to be both "Roundup ready" and also larger and higher yielding than the original strains of the plant. [14]^[68] However, there are no reports of glyphosate-resistant coca in the peer-reviewed literature.^[69] In addition, since spraying of herbicides is not permitted in Colombian national parks, this has encouraged coca growers to move into park areas, cutting down the natural vegetation, and establishing coca plantations within park lands.

In many US cities, Roundup is sprayed along the sidewalks and streets, as well as crevices in between pavement where weeds often grow. In many Canada cities its use for cosmetic purposes is either banned or restricted.^[70][71]

References

External links

• Roundup website (Monsanto)
• EPA's Integrated Risk Information System entry for glyphosate the main ingredient in Roundup
• EPA's ground & drinking water consumer factsheet for glyphosate
• Chemical Identification and Use for Glyphosate, isopropylamine salt

Further reading

• Baccara, Mariagiovanna, et al. Monsanto's Roundup, NYU Stern School of Business: August 2001, Revised July 14, 2003.
• Pease W S et al. (1993) Preventing pesticide-related illness in California agriculture: Strategies and priorities. Environmental Health Policy Program Report. Berkeley, CA: University of California. School of Public Health. California Policy Seminar.
• Wang Y, Jaw C and Chen Y (1994) Accumulation of 2,4-D and glyphosate in fish and water hyacinth. Water Air Soil Pollute. 74:397-403
• Marie-Monique Robin. (2008) Le monde selon Monsanto. Arte Editions (book written in french). ISBN 978-2-7071-4918-3. An overview of Monsanto products: PCB, Dioxine,Roundup, Bovine Growth Hormone, OGM.