"Safety evaluation and risk assessment of the herbicide Roundup and its active ingredient, glyphosate, for humans". In Italian, "Valutazione della sicurezza e stima dei rischi dell'erbicida Roundup e della sua molecola attiva, il glifosato, per gli esseri umani". This is the title of a study published in 2000 in the scientific journal Regulatory Toxicology and Pharmacology. And while most of us have never heard of it, for the many governments, parliamentarians and industry figures who have defended the herbicide glyphosate over these decades, it is an extremely well-known text.

The study assured: glyphosate poses no health risks

These 49 pages formed the backbone of many arguments used to grant and renew commercial authorisations for one of the most controversial agricultural chemicals ever. The analysis concluded that the use of Roundup, the flagship product of Monsanto (today Bayer), poses no health risks whatsoever.

Now, however, across each of those 49 pages the word "RETRACTED" looms large in red capital letters. The study in question is suspected of having been written by individuals with blatant, undisclosed conflicts of interest.

The repeated citations by governments and regulatory bodies to authorise glyphosate

Over these twenty-five years, the scientific article has become one of the most cited on glyphosate, particularly by numerous governmental regulatory authorities that have regulated its use over time. Today, however, a notice published by the journal's publisher lists a series of "critical" shortcomings.

These range from failing to include certain studies on the risks of tumour development linked to exposure to the herbicide, to failing to disclose transparently that Monsanto employees had participated in drafting the text. Nor had it been made known that the authors had been remunerated by the same multinational acquired by Germany's Bayer in 2016.

Three heavy blows to the study's credibility

Three heavy blows that have undermined every kind of credibility — not only of the study itself but also of those who signed it. A reprehensible course of conduct, bearing in mind that on the toxicity of glyphosate — which has for years appeared on the list of substances probably carcinogenic to humans maintained by the International Agency for Research on Cancer (IARC) — science has (at the very least) yet to provide a unanimous answer.

The journal's publisher, Elsevier, has confirmed that a review procedure for the study in question has been initiated. It must therefore be noted, in the interest of accuracy, that the outcome of this review is not yet known.

As early as 2002, a group of scientists raised conflicts of interest in a letter

What is known, however, is that as far back as 2002 around twenty scientists wrote a letter to the publisher denouncing "conflicts of interest, lack of transparency and absence of editorial independence" with regard to the paper in question. One of the signatories, Lynn Goldman of George Washington University, commented to the AFP news agency on the retraction of the study, stating that it had been justified "with exactly the same arguments that we raised at the time".

Moreover, in 2017 internal documents leaked from Monsanto revealed the role of company employees in writing the text. For decades, however, nothing was done. This is a matter that also opens up a broader debate on the mechanisms used by the scientific community to "validate" research findings.

Remarkably, Monsanto itself never flinched. In the past it had in fact candidly acknowledged its direct involvement in drafting the text, but had assured that such involvement "had not reached a level that warranted authorship credit".