Governments and mainstream science are failing to protect us — and the environment — from glyphosate.

Little Drop of Poison

The everyday chemical that’s killing us slowly.

Photo by zhang kaiyv on Unsplash.

Last year a landmark case concluded in California. Dewayne Johnson was a school groundskeeper who applied various forms of glyphosate around 30 times per year who developed non-Hodgkin’s lymphoma. At the age of 46, he is predicted to be unlikely to live past 2020, leaving behind a family of three children and a wife. On Friday the 10th August 2018, one of the world’s largest agrochemical companies, Monsanto (now owned by Bayer), was ordered to pay Johnson US $289M in damages for their deemed role in causing his cancer through their glyphosate-containing products, though that amount was later reduced to US $78M. His was the first of a number of similar cases against Monsanto to go to trial in the US, estimated to be in excess of 11 000. This year, 70-year-old Californian Edwin Hardeman was also successful in his case against Monsanto. On the 21st March, a jury found that Roundup was a “substantial factor” in causing his non-Hodgkin’s lymphoma. Liability and damages were set at US $80M.

Glyphosate is a broad spectrum weed killer that was introduced to market in 1974. Since then, it has become the most widely used chemical in agriculture, facilitated by assurances from Monsanto that it was perfectly safe for human use.

How has Monsanto successfully fooled the world for so long?

Glyphosate is systemic, meaning that it’s water soluble, and therefore easily absorbed and transported within organic tissue. It works by inhibiting an enzymatic pathway, known as the shikimic acid or shikimate pathway, responsible for growth in plants, fungi and some bacteria. Inhibition of the shikimate pathway leads to rapid cell death in the affected organism. It’s non-selective, meaning that it will act upon any plant or microorganism that’s exposed to it, killing it within a matter of days. However, genetically modified (GM) strains of crop plants have been developed that are resistant to glyphosate because of their genetic profile, which has seen it even more widely used. Frighteningly, these crops are still able to absorb the chemical but not metabolise it, meaning that trace amounts remain in the end product i.e. GM food. Analysis of popular breakfast cereals in the US showed that trace amounts were present in 43 of the 45 of the cereals tested.

There are strict guidelines around glyphosate use in food production, including maximum recommended doses, withholding periods and optimum conditions for application. However, with little in place to ensure that these guidelines are adhered to, there’s no guarantees. In vineyards, glyphosate is sprayed under vine rows to inhibit weed growth. In theory, it shouldn’t come into contact with the vine itself nor the roots when applied correctly, so the risk of absorption is limited. But, if applied in the wrong conditions i.e. on a windy day, the risk of misapplication is increased. Glyphosate has been found in wine, including organic wines, indicating that contamination through runoff or wind displacement likely is at fault. While the glyphosate concentrations found were lower than what’s deemed to be unsafe for human consumption, it does pose the question: how did it get there in the first place if correct protocols were followed? And what happened to glyphosate’s supposed rapid decomposition?

Additionally, the Grain Producers Australia chairman admitted in 2016 that he knew of glyphosate being used outside of current withholding periods in the grain industry as producers seek to maximise the output of their crops. While those who grow for export markets stand to lose contracts if glyphosate is detected in their product, the same incentive does not appear to exist for domestic producers.

Glyphosate has also been shown to lead to leaching of organic soil carbon, which negatively impacts soil structure and therefore nutrient and water bioavailability to the plant, as well as increasing runoff of nitrogen, which is a groundwater pollutant. This has important connotations not only for waterways, but also for our ability to produce high-quality food crops ongoing. Healthy soils are crucial for agricultural production. In the face of dwindling mineral resources, particularly phosphate, crucial to soil health and our food production systems, we can ill afford to impair our soils’ ability to produce food.

There has been a growing debate in recent years over the potential human health risks posed by glyphosate use, mainly due to its ability to act as an endocrine system disruptor, from which a number of other health risks seem to stem. The World Health Organisation and the International Agency for Research on Cancer (IARC) caused a stir in 2015 when they announced that glyphosate was “probably carcinogenic” after IARC published an exhaustive review of the publicly available scientific evidence (based on human studies, animal studies, and mechanistic factors), which demonstrated a causal relationship between glyphosate-containing products and non-Hodgkin lymphoma. This finding was called into question (largely by agrochemical industry employees and representatives) through what we might call fairly shabby misinterpretations of the review, which cited IARC’s finding of “limited evidence” for a causal relationship to cancer in humans as a sticking point. Not an unsurprising limitation given that in many cases, the origin of most agrochemical research funding is… agrochemical companies. It’s widely acknowledged in the scientific community that funding sources influence the scope and subject of scientific research topics — and which studies actually get published.

Furthermore, the difficulty of undertaking a simple cause and effect study in humans is almost insurmountable. No ethics committee would approve it and even if they did, what researcher would embark on such a dangerous pursuit? Not to mention the unlikelihood of finding willing study participants.

Instead, the studies used were generally based on incidence of cancer in communities that faced exposure to glyphosate, which relies very much on having a researcher take interest in the right place at the right time, plus get funding to undertake their research. However, additional evidence from animal studies and mechanistic factors support the finding of a causal relationship.

The IARC finding was later defended and verified by 97 scientists and experts in an article published in the Journal of Epidemiology and Community Health.

Perhaps one of the most important points highlighted in the IARC’s review is the incidence of glyphosate in the blood and urine of agricultural workers, which is an indicator of its absorption. It has also been found in higher levels in the urine of people who consume conventional produce as opposed to organic produce, giving us a clue as to the source. And one of glyphosate’s derivatives, aminomethylphosphoric acid (AMPA), has been found in human blood following poisonings.

Glyphosate has been shown to cause oxidative stress in rodents, induce DNA and chromosomal damage in mammals, and in one study, human residents of an Ecuadorian community were shown to have increases in blood markers of chromosomal damage after spraying of glyphosate formulations.

In South America, there has been a reported increase in birth defects since the introduction of glyphosate to rural areas, and a number of other reports of poor health outcomes suspected to be related to exposure to glyphosate in vitro. A systematic review of the current scientific literature shows no causative relationship between glyphosate and adverse pregnancy outcomes in humans, though the study’s authors acknowledge that glyphosate has not been shown not to cause adverse pregnancy outcomes (other than higher incidences of ADHD in children born to glyphosate users). Moreover, studies done with commercial formulations containing glyphosate, diluted to less than agricultural concentrations, have shown birth defects in lab animals.

Effect of glyphosate injection; left to right: control embryo not injected with glyphosate; embryo injected in one cells only; and embryo injected in both cells. Note the reduction of the eye. From Science in Society Archive.

There is one other confounding aspect of the research around glyphosate use. Much of the lab-based testing has been done with glyphosate in isolation, rather than the formulations used in commercial applications. For instance, Roundup is not comprised entirely of glyphosate, it is glyphosate plus a blend of surfactant compounds which enhance its bioavailability. Commercial formulations have been shown to have up to 100 times greater efficacy than glyphosate in isolation. This is not just a terrible example of a failing on the behalf of regulators and authorities to recognise bad, irrelevant science, but it speaks of the negligent attitude that neoliberal agricultural policy cultivates.

All of that aside, the most damning piece of evidence in the Johnson trial came from Monsanto themselves. Companies are not obliged to publish the results of privately conducted research; it is left to their own discretion to pick and choose what makes it into the public realm. Yet they do have a legal duty of care to uphold.

In the Johnson case, the jury were shown internal emails amongst company executives that demonstrated how Monsanto repeatedly ignored scientific warnings and sought and publicised favourable research, while employees ghost-wrote scientific studies that painted glyphosate in a positive light to be published under the names of scientists. According to one of Johnson’s lawyers, Monsanto had been privy to the knowledge that glyphosate plays a causative role in cancer for years. The jury found Monsanto to not only be responsible for Mr Johnson’s non-Hodgkin’s lymphoma, but was also found to have “acted with malice or oppression” and was responsible for “negligent failure” as it did or should have been aware that glyphosate is dangerous to human health.

From a legislative standpoint, it seems like something has to give. In the wake of the IARC’s 2015 findings, there have been small, but incremental changes in how glyphosate is perceived by legislative bodies globally. France acknowledged glyphosate as a probable carcinogen, banning its sale this year. Its use is banned in Sri Lanka. In 2017, California became the first US state to list it as a chemical known to cause cancer, which was later challenged by Monsanto. In 2018, that decision was upheld. A growing list of other countries and states are also clamping down on glyphosate use. In 2017, the EU renewed the licence for glyphosate for just five years. The Johnson and Hardeman cases filled our headlines since last year. It is seeming increasingly inevitable that glyphosate will be banned.

However, this will come at no small cost. In the UK alone, it’s estimated that a ban on glyphosate will cause a decrease in yields across a range of crops that will cost the economy some 630 million euros. In Australia, around AU $17 billion worth, or 68%, of our crops are grown with the use of agrochemicals.

In the area where I live, many farmers have grown reliant on glyphosate use. They have been told by agricultural scientists (who base their views on the available research i.e. that funded by agrochemical companies) that using glyphosate is the only way that they can make a living from farming. As a result, they’re scared. But what nobody has told them is that the alternative is far more frightening— a little drop of poison, killing us slowly.