“Half of People in Europe have Glyphosate Residues in their Urine”

(May 11th, 2017) Later this year, the EU will decide about the future of Roundup in Europe. We spoke with biochemist Michael Antoniou, who together with colleagues, recently voiced concern over the use of the herbicide.





Since it was introduced by Monsanto in 1974, glyphosate-based herbicide Roundup has become one of the major pesticides used worldwide. These days, it’s used not only in agriculture but also in domestic and urban environments. As the European Union reviews its licence for the next 15 years, Michael Antoniou, based at the King’s College in London, believes it’s time to look at recent data challenging glyphosate’s long-accepted safe status and examine whether allowed levels may be outdated.


Currently, what is glyphosate used for?

It depends on the part of the world. Glyphosate is a broad-spectrum herbicide, which means it will kill all plants that are sensitive to it. In agriculture, glyphosate was typically used to clear weeds from fields before planting the crop but now, especially in northern Europe, we’re seeing glyphosate being used as a harvest desiccant. In this case, a few days before harvest, the farmer sprays the crops with a glyphosate-based herbicide, such as Roundup, and kills the crop. This allows the grain to dry more quickly and to be harvested sooner. This method has been increasingly used especially in cereal crops, such as wheat, barley, oats, and rye; but also on oilseed rape and canola and various pulses. Glyphosate is also used domestically. People buy it and spray it in their garden. It’s also sprayed to clear weeds in school grounds, parks, along railway tracks and roadsides. If you go to North or South America, in addition to these uses, glyphosate is used in combination with glyphosate-resistant GM crops. In fact, it’s the expansion of these glyphosate-tolerant crops that has resulted in a massive increase in use globally in the last 20 years.


What is the current legislation in Europe?

At the moment, farmers are free to use it as they wish. The licence to renew the commercial use of glyphosate-based herbicides is currently under review by the European Union, which is considering whether to renew the licence. Last year, the current licence came to an end but, as there was a lot of controversy surrounding its safety, the EU regulator decided to defer its decision and granted an interim 18 months extension to allow further deliberations. We’re in the middle of this period now. The World Health Organisation’s cancer agency IARC has classified glyphosate as a probable human carcinogen (group 2A) but the European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA) disagree, and have pronounced glyphosate non-carcinogenic. Some countries have taken unilateral decisions to restrict its use. For example, in France, its domestic use has been banned.


When should we expect a final answer?

The 18 months are up in December this year, so the decision has to happen between now and the end of the year. If the European Commission decides that, based on the latest scientific evidence, glyphosate is not safe, then it can either put forward a proposal to restrict its use – for instance, to agriculture only – or to ban it completely. EU member states would then make the final decision. If IARC’s verdict that glyphosate is a probable carcinogen were accepted, then it would have to be banned completely, because the EU has a zero tolerance approach for compounds that are accepted to be carcinogenic.


What scientific evidence was used for previous deliberations?

We believe there were flaws in the argument used to grant market approval for the use of this herbicide. We published a paper in 2012 that highlighted evidence that had been ignored by regulators and which indicated that the dose, at which the regulator had suggested it was safe for intake of glyphosate, was set at least 3 times too high and possibly up to 12 times too high. More recent revelations have been unearthed as a result of a cancer litigation in the US, in which plaintiffs are contending that exposure to glyphosate herbicides caused non-Hodgkin’s lymphoma. Internal Monsanto documents reveal that the company proposed that its employees ghost-write a scientific review, arguing for glyphosate’s safety.

MEPs (Members of the European Parliament) have raised questions about the validity of the decisions on glyphosate made by EFSA and ECHA, based on the fact that the suspect review sponsored by glyphosate manufacturers was cited by those agencies in their reports. In addition, questions have been raised in the court case about the role of a top US EPA official, Jess Rowlands, who allegedly worked with Monsanto to “kill” another agency’s investigation into the chemical’s safety.


What do more recent studies show? Can glyphosate affect humans?

This is where the controversy starts. If you look objectively at the data, then you have to come to the conclusion that both glyphosate and its commercial formulations are carcinogens. There are more powerful carcinogens but it’s, nevertheless, true that, given enough time, glyphosate has carcinogenic effects in laboratory animal tests. On the other hand, if you talk to the industry, they argue that it’s not a carcinogen. All this debate about whether glyphosate is a carcinogen, or not, has, to some degree, detracted attention from other mechanisms of toxicity of glyphosate-based herbicides. For example, we have shown that glyphosate can interfere with the energy metabolism, it can cause oxidative stress damage to organs, and even an incredibly low dose of Roundup administered to rats over two years causes kidney and liver damage. We identified that the livers of rats, after a dose of glyphosate-equivalent of Roundup many thousands of times below the regulatory-permitted level for daily ingestion, causes non-alcoholic fatty liver disease and the more severe form known as non-alcoholic steatohepatitis.


How about epidemiological studies? Is there any evidence of increased rates of cancer or liver conditions among regular users?

There are epidemiological studies showing an association between glyphosate herbicide exposure and cancer (non-Hodgkin’s lymphoma), as mentioned by IARC in its report. IARC said that these studies provided “limited” evidence of carcinogenicity but this is only one degree lower than its top category, “sufficient” evidence. There are no studies on glyphosate herbicide exposure and liver conditions but these are crying out to be done.

The surveys of the general population on glyphosate residues that have been conducted to date found that, in the US for example, almost everybody has glyphosate residues in their urine, while about half of people in Europe have glyphosate residues in their urine. These levels have been dismissed because they reflect a level daily ingestion that is below what the regulator has set as safe. But for me, this is not acknowledging the latest evidence, which indicates that toxicity can appear in controlled animal studies ingesting levels below what is considered safe.


If you were in charge of the decision, what would you recommend?

At the very least, I would severely restrict the use of glyphosate-based herbicides, even in agricultural contexts. I would, for example, ban its use as a pre-harvest desiccant. The reason I would ban it is because the harvest is so soon after application of glyphosate herbicides that it would inevitably result in high residue levels, exposing the consumer to higher levels of ingestion than would otherwise be the case. Both in in Europe and the US, glyphosate residues are readily detected in many products, including bread, flour and other cereal products. The only way glyphosate can end up in these products is through use of glyphosate as a pre-harvest desiccant. You can’t use it at any other time, otherwise it would kill the crop before it matured.

This is what I would recommend. It’s not an outright ban, it’s a highly restricting use of glyphosate-based herbicides to minimise its entry into the food supply and minimise exposure. We no longer know what the safe level of exposure is on a long term basis, and because we don’t know, at the very least, we have to restrict its use.

Interview: Alex Reis

Photo: M. Antoniou




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