Written by Frank M. Lin 11/17/2016 4:21 am – recently I’ve been having arguments (rather than debate) with this Paul Davenport dude on my facebook. I actually know of him from hybrids from way back. But he gets on my nerves because he is really dense and believes GMO is perfectly fine and he believes glyphosate is safe to use. Because the EPA said so. False dude, don’t you know the lobbying is a billion dollar industry in USA? There is so much cover up and fake facts distributed it’s not even funny. This morning I decided to google a little bit and one can easily find evidence to support that glyphosate (major component of Monsanto’s RoundUp) is in fact – evil as hell. I will simply link to articles below.
Paul, if you wish to continue to naively believe in the bullshit they have fed you, go right ahead and enjoy your glyphosate and round ups… for the rest of the sensible people who have decided to wake up with me, trust no one. Do your own research. You shouldn’t blindly follow my blog either. I’ve spent thousands of hours watching and reading… and I’m drawing my own conclusions. Use your brain, it will thank you.
First article source, from Scientific America, published in 2009 – https://www.scientificamerican.com/article/weed-whacking-herbicide-p/
Used in yards, farms and parks throughout the world, Roundup has long been a top-selling weed killer. But now researchers have found that one of Roundup’s inert ingredients can kill human cells, particularly embryonic, placental and umbilical cord cells.
The new findings intensify a debate about so-called “inerts” — the solvents, preservatives, surfactants and other substances that manufacturers add to pesticides. Nearly 4,000 inert ingredients are approved for use by the U.S. Environmental Protection Agency.
Glyphosate, Roundup’s active ingredient, is the most widely used herbicide in the United States. About 100 million pounds are applied to U.S. farms and lawns every year, according to the EPA.
Until now, most health studies have focused on the safety of glyphosate, rather than the mixture of ingredients found in Roundup. But in the new study, scientists found that Roundup’s inert ingredients amplified the toxic effect on human cells—even at concentrations much more diluted than those used on farms and lawns.
One specific inert ingredient, polyethoxylated tallowamine, or POEA, was more deadly to human embryonic, placental and umbilical cord cells than the herbicide itself – a finding the researchers call “astonishing.”
“This clearly confirms that the [inert ingredients] in Roundup formulations are not inert,” wrote the study authors from France’s University of Caen. “Moreover, the proprietary mixtures available on the market could cause cell damage and even death [at the] residual levels” found on Roundup-treated crops, such as soybeans, alfalfa and corn, or lawns and gardens.
The research team suspects that Roundup might cause pregnancy problems by interfering with hormone production, possibly leading to abnormal fetal development, low birth weights or miscarriages.
Monsanto, Roundup’s manufacturer, contends that the methods used in the study don’t reflect realistic conditions and that their product, which has been sold since the 1970s, is safe when used as directed. Hundreds of studies over the past 35 years have addressed the safety of glyphosate.
“Roundup has one of the most extensive human health safety and environmental data packages of any pesticide that’s out there,” said Monsanto spokesman John Combest. “It’s used in public parks, it’s used to protect schools. There’s been a great deal of study on Roundup, and we’re very proud of its performance.”
The EPA considers glyphosate to have low toxicity when used at the recommended doses.
“Risk estimates for glyphosate were well below the level of concern,” said EPA spokesman Dale Kemery. The EPA classifies glyphosate as a Group E chemical, which means there is strong evidence that it does not cause cancer in humans.
In addition, the EPA and the U.S. Department of Agriculture both recognize POEA as an inert ingredient. Derived from animal fat, POEA is allowed in products certified organic by the USDA. The EPA has concluded that it is not dangerous to public health or the environment.
The French team, led by Gilles-Eric Seralini, a University of Caen molecular biologist, said its results highlight the need for health agencies to reconsider the safety of Roundup.
“The authorizations for using these Roundup herbicides must now clearly be revised since their toxic effects depend on, and are multiplied by, other compounds used in the mixtures,” Seralini’s team wrote.
Controversy about the safety of the weed killer recently erupted in Argentina, one of the world’s largest exporters of soy.
Last month, an environmental group petitioned Argentina’s Supreme Court, seeking a temporary ban on glyphosate use after an Argentine scientist and local activists reported a high incidence of birth defects and cancers in people living near crop-spraying areas. Scientists there also linked genetic malformations in amphibians to glysophate. In addition, last year in Sweden, a scientific team found that exposure is a risk factor for people developing non-Hodgkin lymphoma.
Inert ingredients are often less scrutinized than active pest-killing ingredients. Since specific herbicide formulations are protected as trade secrets, manufacturers aren’t required to publicly disclose them. Although Monsanto is the largest manufacturer of glyphosate-based herbicides, several other manufacturers sell similar herbicides with different inert ingredients.
The term “inert ingredient” is often misleading, according to Caroline Cox, research director of the Center for Environmental Health, an Oakland-based environmental organization. Federal law classifies all pesticide ingredients that don’t harm pests as “inert,” she said. Inert compounds, therefore, aren’t necessarily biologically or toxicologically harmless – they simply don’t kill insects or weeds.
Kemery said the EPA takes into account the inert ingredients and how the product is used, whenever a pesticide is approved for use. The aim, he said, is to ensure that “if the product is used according to labeled directions, both people’s health and the environment will not be harmed.” One label requirement for Roundup is that it should not be used in or near freshwater to protect amphibians and other wildlife.
But some inert ingredients have been found to potentially affect human health. Many amplify the effects of active ingredients by helping them penetrate clothing, protective equipment and cell membranes, or by increasing their toxicity. For example, a Croatian team recently found that an herbicide formulation containing atrazine caused DNA damage, which can lead to cancer, while atrazine alone did not.
POEA was recognized as a common inert ingredient in herbicides in the 1980s, when researchers linked it to a group of poisonings in Japan. Doctors there examined patients who drank Roundup, either intentionally or accidentally, and determined that their sicknesses and deaths were due to POEA, not glyphosate.
POEA is a surfactant, or detergent, derived from animal fat. It is added to Roundup and other herbicides to help them penetrate plants’ surfaces, making the weed killer more effective.
“POEA helps glyphosate interact with the surfaces of plant cells,” explained Negin Martin, a scientist at the National Institute of Environmental Health Sciences in North Carolina, who was not involved in the study. POEA lowers water’s surface tension–the property that makes water form droplets on most surfaces–which helps glyphosate disperse and penetrate the waxy surface of a plant.
In the French study, researchers tested four different Roundup formulations, all containing POEA and glyphosate at concentrations below the recommended lawn and agricultural dose. They also tested POEA and glyphosate separately to determine which caused more damage to embryonic, placental and umbilical cord cells.
Glyphosate, POEA and all four Roundup formulations damaged all three cell types. Umbilical cord cells were especially sensitive to POEA. Glyphosate became more harmful when combined with POEA, and POEA alone was more deadly to cells than glyphosate. The research appears in the January issue of the journal Chemical Research in Toxicology.
By using embryonic and placental cell lines, which multiply and respond to chemicals rapidly, and fresh umbilical cord cells, Seralini’s team was able to determine how the chemicals combine to damage cells.
The two ingredients work together to “limit breathing of the cells, stress them and drive them towards a suicide,” Seralini said.
The research was funded in part by France’s Committee for Research and Independent Information on Genetic Engineering, a scientific committee that investigates risks associated with genetically modified organisms. One of Roundup’s primary uses is on crops that are genetically engineered to be resistant to glyphosate.
Monsanto scientists argue that cells in Seralini’s study were exposed to unnaturally high levels of the chemicals. “It’s very unlike anything you’d see in real-world exposure. People’s cells are not bathed in these things,” said Donna Farmer, another toxicologist at Monsanto.
Seralini’s team, however, did study multiple concentrations of Roundup. These ranged from the typical agricultural or lawn dose down to concentrations 100,000 times more dilute than the products sold on shelves. The researchers saw cell damage at all concentrations.
Monsanto scientists also question the French team’s use of laboratory cell lines.
“These are just not very good models of a whole organism, like a human being,” said Dan Goldstein, a toxicologist with Monsanto.
Goldstein said humans have protective mechanisms that resist substances in the environment, such as skin and the lining of the gastrointestinal tract, which constantly renew themselves. “Those phenomena just don’t happen with isolated cells in a Petri dish.”
But Cox, who studies pesticides and their inert ingredients at the Oakland environmental group, says lab experiments like these are important in determining whether a chemical is safe.
“We would never consider it ethical to test these products on people, so we’re obliged to look at their effects on other species and in other systems,” she said. “There’s really no way around that.”
Seralini said the cells used in the study are widely accepted in toxicology as good models for studying the toxicity of chemicals.
“The fact is that 90 percent of labs studying mechanisms of toxicity or physiology use cell lines,” he said.
Most research has examined glyphosate alone, rather than combined with Roundup’s inert ingredients. Researchers who have studied Roundup formulations have drawn conclusions similar to the Seralini group’s. For example, in 2005, University of Pittsburg ecologists added Roundup at the manufacturer’s recommended dose to ponds filled with frog and toad tadpoles. When they returned two weeks later, they found that 50 to 100 percent of the populations of several species of tadpoles had been killed.
A group of over 250 environmental, health and labor organizations has petitioned the EPA to change requirements for identifying pesticides’ inert ingredients. The agency’s decision is due this fall.
“It would be a big step for the agency to take,” said Cox. “But it’s one they definitely should.”
The groups claim that the laws allowing manufacturers to keep inert ingredients secret from competitors are essentially unnecessary. Companies can determine a competitor’s inert ingredients through routine lab analyses, said Cox.
“The proprietary protection laws really only keep information from the public,” she said.
This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.
In March, the World Health Organization’s International Agency for Research on Cancer (IARC), issued a statement (also published in The Lancet) that re-classified glyphosate as “probably carcinogenic to humans”. It was a surprise to some in the scientific community because every major regulatory agency had determined that glyphosate, an herbicide often paired with genetically modified crops, was not carcinogenic. In fact, it’s lethal dosage measure is about that of common table salt. So why how did IARC reach such a classification? According to the IARC summary–the full report has not yet been released and may not be for months–because of:
Limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma. The evidence in humans is from studies of exposures, mostly agricultural, in the USA, Canada, and Sweden published since 2001. In addition, there is convincing evidence that glyphosate also can cause cancer in laboratory animals.
Anti-GMO groups jumped on the report, led by anti-GMO crusader, NaturalNews.com, acting as point in a global campaign to ban glyphosate, which is better known as Monsanto’s Roundup (although it is widely sold in generic form).
In response to a recent International Agency for Research on Cancer report, which found that the Monsanto herbicide glyphosate “probably” causes cancer in humans, a cohort of international doctors is now petitioning the European Union Parliament, the EU Commission, and several other health and food safety authorities to take action by banning the use of this prolific chemical.
The website for Moms Against Monsanto declared that “Top Medical Journal, WHO Confirm: Monsanto’s Flagship Product Probably Causes Cancer.” Not to be outdone, Common Dreams declared “Glyphosate, Favored Chemical of Monsanto & Dow, Declared ‘Probable’ Source of Cancer for Humans.” Anti-GMO NGOs have been relentlessly flogging this report since.Even more scientifically oriented publications couldn’t resist overstepping in characterizing the review.
Scientific American declared “Widely used herbicide linked to cancer.” The science magazine had earlier published a post quoting a study by Gilles-Éric Séralini in an article entitled “Weed-Whacking Herbicide Proves Deadly to Human Cells.”
Some countries even took the IARC report to heart enough to suspend uses of glyphosate.
Comparing apples and Roundup
Does glyphosate pose a genuine danger to humans? The mainstream press has tried to separate the scare from the science, but it’s been a challenge because of the confusion of what IARC was evaluating and scientists in general assess the potential hazards and risks of chemicals. IARC does not evaluate actual human risks–a fact widely misunderstood by the public in general. Regulatory agencies do that. Rather, IARC looks at what is called “hazards”.
Note the focus of the IARC review. Quoting Nature’s summary:
The IARC review notes there is limited evidence for a link to cancer in humans. Although several studies have shown that people who work with the herbicide seem to be at increased risk of a cancer type called non-Hodgkin lymphoma, the report notes that a separate huge US study, the Agricultural Health Study, found no link to non-Hodgkin lymphomas. That study followed thousands of farmers and looked at whether they had increased risk of cancer.
But other evidence, including from animal studies, led the IARC to its ‘probably carcinogenic’ classification. Glyphosate has been linked to tumours in mice and rats — and there is also what the IARC classifies as ‘mechanistic evidence’, such as DNA damage to human cells from exposure to glyphosate.
Like glyphosate, almost anything can present a hazard, from the sun to chemicals to everyday foods like coffee depending upon exposure. British based Sense About Science just issued an explainer on the glyphosate controversy to help dispel the fog of confusion about what this review actually means. What is IARC, it asks?
The IARC is an agency of the World Health Organization (WHO) which aims to identify causes of cancer. It brings together groups of scientists to review scientific evidence in order to recognise chemicals, physical and biological agents, and lifestyle factors that can cause cancer in humans.
The IARC do not carry out a risk assessment but rather assess the potential of an agent to be carcinogenic. It does not take into consideration how much of or how commonly a risk it poses in the real world.
We’ve translated the IARC’s carcinogen list into something you can read here. Warning: You might be shocked…
What’s been overlooked is that the classification that IARC assigned glyphosate—a “2A, Probably carcinogenic to humans”—is the same classification the organization gave to grapefruit juice, fruits (including apples), and working the night shift. At least glyphosate didn’t rate a “1, carcinogenic to humans,” so it’s not as dangerous as sunlight, sunlamps, oral contraceptives, Chinese style salted fish and alcoholic beverages, among a long list.
When IARC comes to a determination of what may cause cancer, it combs through existing literature (which does raise the risk of cherry-picking studies that satisfy your point of view). But it’s assessing the hazard of a chemical. A hazard assessment simply states that a certain chemical, environmental element or behavior is somehow related to cancer. It’ll then note whether something “is,” “is probable” or “is possible”, or “isn’t,” so far as we know.
What a hazard evaluation does not tell you is how likely you are to get cancer. That’s the domain of a risk assessment, which will use the same words–“is,” “probable” and “possible”–but in a different way. Here’s a very informative video explainer by Andrew Maynard, director of the Risk Innovation Lab at Arizona State University, that covers how IARC makes its hazard assessments:
Risks versus hazards
While a hazard just shows you that “somebody out there linked this to cancer,” a risk measures how likely you are going to come into contact with this hazard. So, in the case of apples and pears, IARC looked at the existence of amygdalin, or formaldehyde, both of which are considered class 1 carcinogens and occur naturally in apples. But apples contain 22 parts per million of formaldehyde, far below amounts necessary to cause cancer. In short, dose matters.
Likewise, a report trumpeted by Moms Across America, for example, claimed the existence of glyphosate in mother’s milk, but it was not actually a study and has been challenged by many scientists, most recently by researchers at Washington State University.
Most foods do contain certain chemicals that are associated with toxicity. But each chemical has a dosage curve showing how much ingestion is needed to cause harm, and most foods contain very low doses of these toxins. As the US Centers for Disease Control and Prevention states,
Just because we can detect levels of an environmental chemical in a person’s blood or urine does not necessarily mean that the chemical will cause effects of disease.
This explains why IARC, a WHO subsidiary, can issue reports on cancer hazards, while the World Health Organization itself declares that the IARC study does not indicate a need for more regulation of glyphosate. In fact, several other government agencies, including the German government and (so far) US Environmental Protection Agency, have issued statements on the doses of glyphosate that cause harm and the low cancer risk of the popular and targeted weed-killer:
- The German Federal Institute for Risk Assessment re-examined data on glyphosate and declared that “the available data do not show carcinogenic or mutagenic properties of glyphosate nor that glyphosate is toxic to fertility, reproduction or embryonal/fetal development in laboratory animals.” The institute did find toxicity that originated from surfactants and other co-formulants used in the making of some glyphosate products.
- The EPA and other US agencies have considered glyphosate’s cancer risk to be low (the EPA declared glyphosate as noncarcinogenic in 1991), but the EPA is currently reviewing the chemical for weed resistance as well as other properties.
Sense About Science and other groups maintain that even as a hazard evaluation, IARC badly botched its job.
Scientists have criticised the IARC glyphosate assessment for numerous reasons:
- The selection of literature for reviewing was unbalanced and data has been ‘cherry picked’
- No new scientific evidence was included in this evaluation
- This classification is based mostly on animal studies and the report states that there is limited evidence of carcinogenicity in humans
- It contradicts the conclusions of several national regulatory agencies around the world that have reviewed the large body of glyphosate research and deemed it a safe herbicide
…The dose makes the poison
It’s important to remember that any chemical, whether natural or synthetic can hurt us if we consume too much of it. The dose is the crucial factor.
The responsibility of IARC and similar organizations doing hazard evaluations is to review the scientific literature (or sometimes conduct their own limited research) to classify the potential theoretical dangers that a chemical could pose–but not in real world usage. Then, it’s up to regulatory agencies using risk metrics to compare what’s known about toxic exposure levels of the hazard with actual exposure in humans or animals. It’s this assessment that informs us whether something might pose genuine health dangers, such as cancer.
So what does science tell us about glyphosate? It’s not carcinogenic and is safe as used. If you question that based on the IARC hazard study, perhaps you should consider advocating bans of grapefruits, apples or night shift work.
Andrew Porterfield is a writer, editor and communications consultant for academic institutions, companies and non-profits in the life sciences. He is based in Camarillo, California. Follow @AMPorterfield on Twitter.
Article three source The Guardian (England): https://www.theguardian.com/environment/2016/jan/13/eu-scientists-in-row-over-safety-of-glyphosate-weedkiller
A bitter row has broken out over the allegedly carcinogenic qualities of a widely-used weedkiller, ahead of an EU decision on whether to continue to allow its use.
At issue is a call by the European Food and Safety Authority (Efsa) to disregard an opinion by the WHO’s International Agency for Research on Cancer (IARC) on the health effects of Glyphosate.
Glyphosate is sold and promoted by Monsanto for use with its GM crops. The herbicide makes the company $5bn (£3.5bn) a year, and is used so widely that its residues are commonly found in British bread.
But while an analysis by the IARC last year found it is probably carcinogenic to humans, Efsa decided last month that it probably was not. That paves the way for the herbicide to be relicensed by an EU working group later this year, potentially in the next few weeks.
Within days of Efsa’s announcement, 96 prominent scientists – including most of the IARC team – had fired off a letter to the EU health commissioner, Vytenis Andriukaitis, warning that the basis of Efsa’s research was “not credible because it is not supported by the evidence”.
“Accordingly, we urge you and the European commission to disregard the flawed Efsa finding,” the scientists said.
In a reply last month, which the Guardian has seen, Andriukaitis told the scientists that he found their diverging opinions on glyphosate “disconcerting”. But the European Parliament and EU ministers had agreed to give Efsa a pivotal role in assessing pesticide substances, he noted.
“These are legal obligations,” the commissioner said. “I am not able to accommodate your request to simply disregard the Efsa conclusion.”
A few days later, Efsa’s executive director Bernard Url hit back, complaining to the European parliament’s environment committee that the scientists had not seen the evidence, and were leaving the domain of science by making their criticisms public.
“This is the first sign of the Facebook age of science,” he said. “You have a scientific assessment, you put it in Facebook and you count how many people like it. For us, this is no way forward. We produce a scientific opinion, we stand for it but we cannot take into account whether it will be liked or not.”
However, unease within Url’s group was growing and at the next Efsa executive meeting, board members talked candidly of a “crisis” over the issue.
As well as finding the IARC’s analysis “far more credible”, the critique by the 96 scientists had appeared to snipe at Efsa’s vulnerability to influence from interest groups.
The IARC paper had relied “on open and transparent procedures by independent scientists who completed thorough conflict of interest statements and were not affiliated or financially supported in any way by the chemical manufacturing industry,” the scientists’ letter said.
Five of Efsa’s 80 or so mammalian toxicology experts failed to file a declaration of interests, while some of those that were submitted were several years old. More than a third of the experts were also employed by national regulators and one had a 5% stake in a risk assessment consultancy.
Given the highly charged nature of the debate, EU officials privately say that the issue is most likely to be resolved in a classic Brussels-style fudge.
“The way out may be to put more limitations on certain products [containing glyphosate], or allowing member states to do that,” one EU source said. “There is a problem of the combination of glyphosate and some other substances. That is part of the reason for the difference between IARC and Efsa. But if you have additional restrictions for certain products, you give member states some leeway.”
In a letter sent today, Url defended Efsa’s study as a “more comprehensive hazard assessment” than the IARC paper which, he said, had not tried to differentiate between the carcinogenic effects of glyphosate and other ingredients in pesticide packages, or their combined effects.
Efsa and IARC had agreed to meet early in 2016 “in an effort to clarify scientific divergences,” Url added.
- This article was corrected on 13 January 2016 to say that glyphosate is sold and promoted by Monsanto for use with its GM crops. It was not developed by the firm for such use.
Fourth article source: https://www.biofortified.org/2013/10/glyphosate-toxic/
Of course glyphosate is toxic! It is a herbicide after all – the whole point of glyphosate (G for short in this post) is to kill unwanted plants. Like all chemicals, including water and salt, G is going to be toxic to animals (including humans) at somedose. Compared to other herbicides, though, G is a pretty safe option for killing weeds. Don’t take my word for it, check out the Glyphosate Technical Fact Sheet from the National Pesticide Information Center at Oregon State. G’s relative safety is one reason why it’s become so popular.
One interesting use of G is to dry wheat before harvest. To help reduce levels of toxic fusarium fungus on wheat, it is good to harvest the wheat as early as possible but you can’t harvest it until it’s dry. So G is used to dry (aka kill) the wheat plants so the grain can be harvested. As long as the G is sprayed after the plants have fully matured, the G won’t be moved from the plant into the seeds. Here, G is actually helping farmers prevent a legitimately scary toxin from getting into the food supply. Want to learn more? Check out this video: Wheat School- Timing Pre Harvest Glyphosate Application In Wheat.
With G being used not only as a herbicide but also as a drying agent, and not just in our lawns but on our food, should we worry about our safety? In short, no. When used properly, G is quite safe for humans.
The EPA sets maximum safe levels of pesticide residues for crops (called tolerances), based on the latest science. These tolerances are hundreds of times higher than estimated toxic values, and they consider a person’s total exposure to pesticides (with a wide margin of error to protect children and others who may be vulnerable). The USDA tests crops each year to make sure they don’t go above the tolerances. Very few pesticides are found above the tolerance levels (despite what the Dirty Dozen list claims). If the USDA finds any pesticides above the set tolerance, or finds pesticides on crops where they aren’t supposed to be, they report that information to the FDA. The FDA puts the teeth in this whole system. They have the regulatory power to start recalls, levy fines, turn back foods at the ports, and so on (see page 5).
You can find the specific tolerance information for G in the US Code of Federal Regulations, 40 CFR, part 180, subpart C, section 180.364. Some of the tolerances for G were recently increased in the May 1, 2013 Federal Register, Vol. 78, No. 84.
EPA has reviewed the available scientific data and other relevant information in support of this action. EPA has sufficient data to assess the hazards of and to make a determination on aggregate exposure for glyphosate including exposure resulting from the tolerances established by this action. EPA’s assessment of exposures and risks associated with glyphosate follows.
Check out Vol. 78, No. 84 for a full explanation of EPA’s decision as well as insights into the safety of G in general. Scientific documents supporting this decision can be found in docket EPA-HQ-OPP-2012-0132.
Tolerances don’t set your mind at ease? Happily there’s a lot of research to peruse.
If you don’t want to dig through these dense EPA documents, you can take a look at three recent reviews that summarize the literature on glyphosate and humans: Epidemiologic studies of glyphosate and non-cancer health outcomes, Epidemiologic studies of glyphosate and cancer, and Developmental and reproductive outcomes in humans and animals after glyphosate exposure. These reviews looked at epidemiological studies, ones that look at disease incidence in large numbers of humans with varying levels of exposure to G or that look at exposure to G in a population that has a disease.
Now, epidemiology isn’t perfect, but with carefully designed studies it can be a powerful way to look for connections in real human populations. Even better when we can look at reviews that put multiple studies all in one place. These reviews cover a lot of studies that find there is no correlation between glyphosate exposure and cancer or non-cancer diseases. Unfortunately these reviews are behind paywalls and I don’t know the funding source behind the reviews, but the EPA documents have summaries of many of the studies within the reviews and more.
There are occasionally alarm-inducing papers like Glyphosate induces human breast cancer cells growth via estrogen receptors. This paper, and others like it, tend to use human cells in a petri dish rather than whole animals. I had the misfortune to do some research on cultured human cells myself and let me tell you, those are some tricky buggers to work with. Even when everything is working perfectly, it’s still very hard to tell if the results you are getting will hold true when repeated in a whole animal model. Something that causes a reaction in naked cells may not react the same when applied to your skin or taken in through your digestive system (both of which have evolved to keep you safe from many things).
Only a combination of animal models and cell studies can give us the full picture (even better if we can pair these up with some epidemiology). The third review above includes some animal studies as do the EPA reports. While I am cautious about cell studies in general, the majority of such studies have not found any cause for concern, as described in Review of genotoxicity studies of glyphosate and glyphosate-based formulations (open access) as well as in the EPA reports.
In any subject there will be a few studies that find something totally different from what is found in the majority of similar studies. In closing, I leave you with this recent strangeness: Glyphosate and AMPA inhibit cancer cell growth through inhibiting intracellular glycine synthesis. This obviously tongue-in-cheek meme plays on so many scaremongering memes created about single studies. As interesting as a single study may be, we must look at the totality of evidence. And so far, the evidence does not show that that glyphosate causes – or cures- cancer.
Mink P.J., Mandel J.S., Lundin J.I. & Sceurman B.K. (2011). Epidemiologic studies of glyphosate and non-cancer health outcomes: a review., Regulatory toxicology and pharmacology : RTP, PMID: 21798302
Mink P.J., Mandel J.S., Sceurman B.K. & Lundin J.I. (2012). Epidemiologic studies of glyphosate and cancer: a review., Regulatory toxicology and pharmacology : RTP, PMID: 22683395
Williams A.L., Watson R.E. & DeSesso J.M. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis., Journal of toxicology and environmental health. Part B, Critical reviews, PMID: 22202229
Kier L.D. & Kirkland D.J. (2013). Review of genotoxicity studies of glyphosate and glyphosate-based formulations., Critical reviews in toxicology, PMID: 23480780