In the March 2015 edition of The Lancet Oncology magazine, the highly reputable organisation, the International Agency for Research on Cancer (IARC) announced that it has classified three pesticides, including glyphosate, in the 2A category, meaning that they are « probable carcinogens ».
Since the article was published, François Veillerette, the President of the anti-pesticide association Générations Futures, has trumpeted his satisfaction. “ Victory - glyphosate, the active ingredient of the famous RoundUp, recognised as carcinogenic by the IARC !” he immediately tweeted.
However, glyphosate is today by far the most widely used herbicide in the world due to its eco-toxicological profile, regarded to date as particularly favourable. It is the active ingredient of over 750 products intended not only for agricultural use, but also for urban and domestic use. Particularly environmentally aware countries, such as Denmark, have widely adopted it, as well as countries which favour transgenic glyphosate-tolerant crops. This herbicide has obviously been under very high surveillance by official health safety organisations in different countries, but also by many militant organisations at war against Monsanto, the company which synthesised it over forty years ago now.
Within this context, the opinion of the IARC could not go unnoticed. As a guest on the 8 pm news on TF1, François Veillerette therefore expressed his wish to have it immediately withdrawn from the market. An opinion not shared by the Minister of Health, Marisol Touraine, who believes it will be better to wait for it to be re-assessed by the European Food Safety Authority (EFSA). Touraine entrusted the task to the Bundesinstitut für Risikobewertung (BfR), the German health safety agency. “I would like to assure you that all of the government is very vigilant”, pointed out the Minister, in response to Laurence Abeille, the ecology spokesman for Générations Futures at the National Assembly.
A conflict of interests
« Banning glyphosate, called for by several NGOs, is not a thing of the future » , deplored journalist Stéphane Foucart at the anti-pesticide lobby. In an article published in Le Monde on 25th March, evidence is cited not from examining its toxicological profile, which still has many advantages, but the composition of the pesticides expert group, BfR, which, he says, poses a problem. « One third of the committee members are directly employed ... by agrochemical and biotechnology giants » , he protested, accusing the German agency of bias due to the presence of three members of the chemical industry (two from Bayer and one from BASF) on a twelve-person panel. However, neither Bayer nor BASF sells glyphosate or a product associated with it. Nevertheless, the journalist did not comment on the rather surprising composition of the IARC expert panel, which has a « specialist guest » Christopher J. Portier, who holds a Masters degree in biostatistics ... and above all he is an employee of the Environmental Defense Fund, a US anti-pesticide group which campaigns for the withdrawal of glyphosate ! Here, the conflict of interests is obvious.
It is understandable that the BfR was quick to react to the IARC’s new classification. Remembering that glyphosate was judged non-carcinogenic by national, European and international institutions (including the common organisation of the WHO and the FAO, the Joint Meeting on Pesticide Residue), the German agency expressed « surprise at this new » , while noting that « in everyday life in the field of risk assessment » organisations reach different conclusions « due to different information and assessments » . Therefore, the BfR is waiting for the exhaustive publication of the monograph (over 400 pages) of the IARC before making any further comments.
No definitive proof
When asked by the British press, Aaron Blair, the President of the expert group which prepared the glyphosate assessment for the IARC, has nevertheless given a broad outline. He stated that the notice is based on three epidemiological case control studies of occupational exposure to glyphosate conducted in Sweden, the United States and Canada, which showed an increased risk of Non-Hodgkin Lymphoma. He also recalled that there were some laboratory studies suggesting that glyphosate induces chromosome breakdown in cultured in vitro human cells and that, in addition, some studies have shown increased rates of cancerous tumours in mice and rats exposed to glyphosate. In other words, it is the conjunction of these studies which justifies placing the product in the 2A category. As the IARC does not have any definitive evidence for concluding that glyphosate is carcinogenic in humans, its experts have thus opted for the classification “probable carcinogen”. Aaron Blair adds that his committee has merely answered a specific question : does a substance possess the mechanisms which enable it, under certain circumstances and a certain level of exposure, to be linked to specific types of cancer in some farmers ? « Whether these circumstances or exposures exist in the real world is a completely different question, one which the IARC has never attempted to answer » , he stated.
Highly theoretical studies
And this makes all the difference with the assessments made to date, confirmed by the BfR’s preliminary report. In fact, as far as research on animals in laboratories is concerned, the IARC has submitted research on those in which glyphosate was directly injected into the abdomens of mice by intraperitoneal injection and almost lethal doses (Bolognesi et al., 1997 ; Peluso et al. , 1997). This is certainly interesting from a theoretical point of view – as they indeed suggest a potential mechanism – yet these textbook cases (in vitro study or in vivo glyphosate injection) are nothing like what happens in the real world ! The study by Heydens et al. . (2008), which managed to cause hepatitis and kidney damage also by glyphosate injection, while no effects were observed when administrated orally, is typical proof. In practice, of the 11 long-term studies carried out on animals, of which the BfR is aware, none show any carcinogenic effects. The German agency can also draw on the work of Greim et al . (2015), which assessed 14 studies of carcinogenicity, including 9 on rats and 5 on mice. The team concludes that there is no proven link between cancer and glyphosate.
There remains the question of Non-Hodgkin Lymphoma, one of the very rare diseases with a higher prevalence among farmers than among urban residents (+34%). While the IARC cites three epidemiological studies (Canadian, American and Swedish), based respectively on 2023, 2583 and 2011 participants, the BfR has compiled the results of over 30 different epidemiological studies. However, none of these suggest that glyphosate is responsible for this increased risk. On the contrary, the largest epidemiological study carried out to date on the agricultural population (50,000 people), entitled the Agricultural Health Study (AHS), leans towards the responsibility of products such as lindane, diazinon, permethrin and terbufos, but never towards glyphosate (Alvanja et al. , 2014, De Roos et al., 2005 and Koutros et al. , 2010).
A lack of rigour or handling ?
In light of currently available information, the IARC’s opinion seems inconclusive. All the more so when reading the summary published in The Lancet, where it seems that its experts have made a serious mistake, which testifies at best to a harsh lack of rigour, and at worst, an outright lack of handling. In fact, the IARC cites the work of Bolognesi et al . on Colombian agricultural workers (2009), which suggests an increase in blood markers in chromosomal damage (micronuclei) in residents of several communities after spraying glyphosate formulations . However, the conclusions of Bolognesi et al. state precisely the opposite ! It finds no correlation between glyphosate sprays and the frequency of blood markers. « Data indicates that the genotoxic risk potentially associated with exposure to glyphosate in areas where the herbicide is applied to eradicate coca and poppies is low », Bolognesi et al . very cautiously conclude.
As a result, the IARC partially legitimises its decision by distorting the conclusions of a study it cites as a reference. This is unheard of for an agency of such international renown, which undoubtedly reflects a malfunction that merits a thorough investigation ...
Translation of the article of the journal Agriculture and Environment Nouvelle étape dans la guerre contre le glyphosate