Glyphosate has adverse health effects from doses considered safe, study shows


Glyphosate has adverse health effects from doses considered safe, a new study shows [Lertwit Sasipreyajun]

Glyphosate, the chemical found in the world’s most widely used weed-killer, can have disruptive effects on sexual development, genes and beneficial gut bacteria at doses considered safe, according to a study presented at the European Parliament on Wednesday (16 May).

The study was conducted by the Italian Ramazzini Institute, in collaboration with several European and American universities.

“Long-term exposure to glyphosate-based herbicide can lead to bioaccumulation of the substance”, said Daniele Mandrioli, coordinator of the research activity of the Ramazzini Institute of Bologna, during the presentation of the study.

He added that glyphosate damages the intestinal microbiome of rats born to mothers exposed to concentrations considered safe, with significant and potentially harmful effects, while exposures can alter sexual development and promote the building of tumours.

Researchers examined the offspring of rats that had accumulated glyphosate levels in tissues of 1.75 micrograms per kilogram of body weight, a level which has been defined as the acceptable daily dose by the American Environmental Protection Agency (EPA).

Glyphosate was administered to rats for three months, dissolved in water. Although the newborn rats did not come directly into contact with the active substance, the researchers observed significant and potentially harmful effects on intestinal microbiome in them.

“The body accumulates glyphosate over time,” Mandrioli explained. “In addition, the herbicides examined may have genotoxic and reproductive consequences on the intestinal flora after exposure to doses considered safe”.

“This is new and it worries us,” added Fiorella Belpoggi, head of research at the Ramazzini Institute and director of the Cesare Maltoni Cancer Research Centre.

The three articles describing the first phase of this large study will be published on 29 May in the Environmental Health journal.

The study considered the effects of glyphosate, the active substance used in the world’s most used and most controversial herbicide, Monsanto Roundup, on Sprague Dawley rats, the strain most used in the pharmaceutical industry for toxicology studies.

Research has not focused on the onset of cancer itself but on the accumulation of the substance and on the alterations of reproductive health.


The Ramazzini study was published a day after the Special Committee on the Union’s authorisation procedure for pesticides (PEST) held its third public hearing on the European procedure for pesticides and the application approval of active substances and draft assessment reports.

The session raised questions about three characteristics of the current legislation that lead to the questioning of the independence of glyphosate-related scientific studies:

The fact that most of the scientific studies are paid for by the company seeking product approval; that some of the studies are not public because of business confidentiality considerations and that the company seeking approval can choose which member state it wishes to be the rapporteur.

The Ramazzini study was financed via crowdfunding.

Helmut Burtscher, a biochemist at the Austrian NGO Global 2000 and author of “Die Akte Glyphosat”, Jean-Philippe Azoulay, from the European Crop Protection Association (ECPA), Andreas Hensel, director of the German federal institute for Risk Assessment (BfR) and Georg Backhaus, from the German Federal Research Centre for Cultivated Plants (JKI), made statements and answered the MEPs’ question during the session.

The president of the special committee, Eric Andrieu, recalled what is at stake: being able to take a decision on the basis of reliable and objective data, meaning free from suspicion of conflict of interest and of copy-pasting studies written by industry representatives.

“It is about the robustness of the European certification system”, he said.

Helmut Burtscher called for a modification of the European homologation procedures while underlining the lack of independence in the assessment of glyphosate-related cancer.

He said that in its assessment, the BfR copy-pasted a study written by a representative of Monsanto. “Neither the sources nor the author of the study is mentioned in the assessment of the BfR,” the biochemist said.

“The BfR has already reviewed its assessment four times and came to the same conclusion, that is, glyphosate is not a carcinogen. And yet, it will do it another time. That will be five times in the row. Can we expect that the BfR will come this time to another conclusion?” he also asked.

The European Food Safety Authority (EFSA) should become the authority to do these re-evaluations, he said.

BfR director Andreas Hensel replied that the German agency did not classify glyphosate as a carcinogen on the basis of the current state of knowledge.

“This decision was made on the basis of an independent and comprehensive evaluation of all available scientific studies,” Hensel said, underlining that authorities worldwide also used original data and concluded that, according to the current state of knowledge, glyphosate should not be classified as a carcinogen.

Hensel also said he wanted more openness and transparency in the evaluation of pesticide active substances while reiterating that “glyphosate is so to say not toxic”.

“The BfR has been supporting the further improvement of the evaluation procedures for years,” he said. “Original toxicological studies should be freely accessible.”

The issue with studies on glyphosate

The UN’s Food and Agriculture Organisation (FAO) and the World Health Organisation (WHO) have approved the chemical, claiming it is “unlikely to pose a carcinogenic risk to humans from exposure through the diet”. The same opinion was shared by the European Food Safety Authority (EFSA) as well as the European Chemicals Agency (ECHA).

However, this is in contrast to an assessment by IARC, which in 2015 concluded that the herbicide solution was “probably carcinogenic to humans”.

EFSA said it had carried out a thorough analysis and taken account of the IARC’s findings. Greenpeace, for its part, called EFSA’s report “a whitewash”.

In October 29017, EU Health Commissioner Vytenis Andriukaitis hinted that sometimes it’s “strange” that people argue against glyphosate by only by focusing on the IARC findings.

“Sometimes they also disseminate the message that the EU does not take into account the IARC’s monograph [on glyphosate],” he told EURACTIV, adding that this is far from reality.

Andriukaitis: ‘Enough’ with member states hiding behind the Commission on glyphosate

The member states should stop hiding behind or even pointing the figure at the European Commission regarding the re-authorisation of the world’s most commonly used weedkiller, glyphosate, EU Commissioner for Health and Food Safety Vytenis Andriukaitis told


“IARC was a first step of the WHO system and we started from the beginning to read the monograph,” the Commissioner stressed, adding that he personally arranged meetings between IARC and EFSA asking them to once again to assess the issue.

“WHO and FAO joined the pesticides committee level. They assessed the monograph of IARC and they decided finally that glyphosate is unlikely carcinogenic,” Andriukaitis noted.

He also hinted that some media “do not always mention it and they say that the Commission does not take into account the IARC monograph. This is not true.”

“Around the world today all the organisations in Japan, Australia, New Zealand, Canada, the US, present the same conclusions on glyphosate is unlikely carcinogenic,” the Commissioner concluded.

In a resolution on 24 October 2017, the European Parliament called on the Commission and member states not to allow household uses of the substance, as well as agricultural uses where non-chemical alternatives exist, after 15 December 2017, with all agricultural uses to be phased out by 15 December 2022.

It also called for risk assessments to be based only on published peer-reviewed and independent studies.

The 30 member committee will hold more public hearings scheduled at the end of August and the beginning of September before releasing its report in December.

Subscribe to our newsletters