Glyphosate is the world’s most widely used herbicide. Is it as safe as its manufacturer claims?

Glyphosate is the principal ingredient in the herbicide named Roundup. It seems miraculous. It is deadly to weeds, yet harmless to humans, or so says Monsanto, the massive chemical company that manufactures it. (In 2018, Monsanto was purchased by Bayer.)

Glyphosate is used on crops such as soybeans, corn and canola. It is used by local governments to control weeds in public areas. It is used on golf courses. It is used by householders to maintain beautiful lawns.

The biggest use is on crops. Glyphosate is deadly to all growing things, so initially Roundup had to be applied to the weeds but not the crops. However, when the patent on Roundup was about to expire, Monsanto developed a brilliant way to maintain sales. Using genetic engineering techniques, it spliced a gene into crops, such as soybeans, that made them resistant to glyphosate. As a result, Roundup could be sprayed directly on the crops. Weeds would be killed, but genetically modified crops would not be harmed. Such crops are called Roundup Ready.

What happened when farmers started reporting disease and scientists started finding problems? If you want the inside story, get Carey Gillam’s book Whitewash: the story of a weed killer, cancer, and the corruption of science. Gillam is an experienced journalist who was put on the agriculture beat and began looking behind the scenes. The picture isn’t pretty. She is now research director at U.S. Right to Know.

The victims and the regulators

Monsanto claimed that Roundup was safe, so safe that you could probably drink it without harm. But what about farmers who had used Roundup for decades and then developed non-Hodgkin’s lymphoma? There seemed to be a pattern, especially given experiments with mice.

What about government regulators? The US Environmental Protection Authority (EPA) is supposed to be protecting the health of both people and the environment. Yet the EPA has seemed to be in the pocket of Monsanto, in all sorts of ways.

The EPA can set upper limits to the intake of chemicals. However, when it came to glyphosate, the limits it set were high, and were increased in line with increased use of the herbicide. This was despite the applications of glyphosate becoming ten times as great over a period of two decades.

You might expect that with glyphosate being the most heavily used herbicide in the world, there would be numerous studies of its prevalence and its impacts. Quite the contrary. For years, no figures were collected of the levels of glyphosate in different crops. The reason: because it was presumed to be safe, there was no need to see what levels were appearing in foods. For years, studies were not carried out on glyphosate’s possible health hazards. Again, the rationale was that it was so safe that there was no need for testing.

Much that Gillam reports relies on documents obtained using the discovery process in court cases, in which parties are required to provide relevant documents to the other side. Monsanto’s activities in subverting scientific research have been remarkable.

Monsanto cultivated allies within the EPA and used them to block introduction of regulations. It cultivated tame scientists who would go on the attack against anyone who criticised glyphosate. These tame scientists were given “talking points” so they would know what to say, and given guidance on venues for giving talks and submitting articles. These tame scientists did not reveal their links to Monsanto. In this way, Monsanto could get out its message via seemingly independent scientists.

Resistance – by pests

According to its promoters and defenders, glyphosate is a miracle chemical, so safe to humans that it can be used widely with little or no impact on human health. However, it is not pure glyphosate that is applied to crops, gardens and walkways, but Roundup, which contains additional chemicals, including one called polyethoxylated tallow amine or POEA. The combination of glyphosate and POEA is what needs to be tested, but this is hardly ever done.

However safe Roundup might be, there’s another problem. Pests can develop resistance to it. This is evolution in action: a few pest species have or acquire resistance to the pesticide, so they are the ones that start growing and spreading.

Because Roundup has been so remarkably effective in eliminating pests, farmers have become complacent. Instead of rotating crops – a traditional practice that reduces pest problems and replenishes the soil – farmers have planted the same crops year after year, relying on Roundup rather than other methods to keep pests at bay.

When Roundup-resistant pests started appearing, what was the solution? Farmers turned to other pesticides, using them in addition to Roundup. Some of these other pesticides are more highly toxic. This is the pesticide treadmill, in which the only solution to pests, even when they become resistant, is more pesticides.

Some farmers had nearly forgotten how to grow crops in traditional ways. Others, though, have turned towards alternatives, including organic agriculture.

History repeats

Is Gillam’s treatment of the glyphosate saga accurate? Her account rings true, because it is history repeating. Monsanto’s response to criticisms of Roundup is remarkably similar to the response by earlier pesticide manufacturers to criticisms.

Rachel Carson’s famous book Silent Spring, published in 1962, raised the alarm about the effect of pesticides on wildlife and, tentatively, on human health. Many people have heard of Silent Spring, which is often credited with inspiring the modern environmental movement. Less well known is that Carson and Silent Spring came under fierce attack by chemical corporations. This is documented in a revealing 1970 book by Frank Graham, Jr., titled Since Silent Spring.

In 1978, biologist Robert van den Bosch’s book The Pesticide Conspiracy appeared. Van den Bosch told about the strong-arm tactics of the pesticide manufacturers, recounting case after case of scientists whose research and careers were attacked after they reported findings critical of pesticides.

Gillam’s story of Monsanto’s tactics to attack any threat to its highly profitable Roundup is eerily similar to the tactics used by pesticide companies since the 1960s. It seems little has changed since, decades ago, I investigated suppression of scientists who questioned pesticides. Given that the tactics are predictable, it is plausible to work backwards and assume that presence of these tactics indicates the likelihood of shortcomings in the pesticide paradigm. So what are the tell-tale tactics?

* Attacks on scientists who report research results showing dangers or limitations of pesticides.

* Regulatory agency dependence on industry testing of pesticides.

* Testing only of the active ingredient, not of the pesticide actually used.

* Corporate ghostwriting of research papers.

* The failure of companies to release documents except through freedom-of-information requests or court discovery processes.

* A revolving door between company jobs and jobs in the corporate regulator.

* Presence on expert panels of members with conflicts of interest.

* Failure to carry out relevant research or collect relevant data, such as amounts and locations of pesticides used.

The presence of these tell-tale signs does not prove that a pesticide, or some other product or practice, is dangerous, but it does point to areas where extra scrutiny is warranted.

If you start investigating the likelihood that corporations and regulators are not serving the public interest, be prepared to be ignored or, if you start having an impact, being the target of dirty tactics.

“Monsanto Company and many leading chemical industry experts tell us that we should trust them and that more research is not needed. The safety of glyphosate and Roundup is proven, they say. But trust is hard to come by when the government does not require robust long-term safety data for a finished product such as Roundup, only for the active ingredient. There have long been concerns that the end product is more dangerous than glyphosate alone, and scientists say it is well-known that extra ingredients in pesticide products not only may themselves be toxic but also may enhance or supplement the toxic effects of the active ingredient. Extra ingredients in pesticides commonly include surfactants that help chemicals stick to the leaves of plants, antifoam compounds, and more. Yet the bulk of industry-sponsored toxicology tests are done using only the active ingredient. As well, there is very little long-term epidemiology data on glyphosate exposure, and there is no established base of information about just how much of the pesticide is in the products we eat and drink because the U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) have so steadfastly avoided including glyphosate in their testing regimes. And despite industry assurances of safety, there is an international body of published research that contradicts those claims.” (pp. 79-80)

Brian Martin
bmartin@uow.edu.au