Roundup Doesn't Poison Only Weeds
By Herve Morin
Le Monde, 12 March 2005
The most used herbicide in the world: Monsanto's Roundup and its competitors, formulated, like Roundup, on a base of glyphosate, have long enjoyed a reputation for harmlessness to human health and the environment. However, several recent studies seem to indicate that this active ingredient, used by farmers as well as by public road services and Sunday gardeners, could well not be as inoffensive as its promoters claim. The stakes are big, because the usage of glyphosate grows along with that of genetically modified organisms, the great majority of which have been specifically conceived to "tolerate" this active ingredient, fatal to plants.
In fact, while Roundup and similar products were originally used against weeds, "they have become a food product, since they are used on GMOs, which can absorb them without dying," maintains the biochemist Gilles-Eric Seralini. A member for years of the French Commission on Biomolecular Genetics (CBG), responsible for preparing the files for requests for field studies, then GMO commercialization, he ceaselessly demands more intense studies on their eventual health impact.
Also a member of Criigen, an association which has made control of GMOs its passion, he has oriented his own research toward the study of the impact of glyphosate. In an article published February 24 in the American journal Environmental Health Perspective, the biochemist and his team from the University of Caen demonstrate, in vitro, several toxic effects of this compound as well as of the additives associated with it to facilitate its diffusion.
For their study, the researchers used human placental cell lines, in which very weak doses of glyphosate showed toxic effects and, at still weaker concentrations, endocrinal disturbances. This, for Gilles-Eric Seralini, could explain the high levels of premature births and miscarriages observed in certain epidemiological studies - which are, however, controversial - covering women farmers using glyphosate. "The effect we have observed is proportional to the dose, but also to the length of exposure," he emphasizes.
His team has also compared the comparative effects of glyphosate and Roundup. And it has observed that the commercial product is more disruptive than its isolated main active ingredient. "Consequently the evaluation of herbicides must take into account the combination with additives in the product," he says.
Gilles-Eric Seralini acknowledges that his study must be extended by animal experiments. But he rejects criticisms that have been made on the absence of any real link between in vitro and normal utilization: "Farmers dilute the pure product and are punctually exposed to doses 10,000 times stronger," he insists. "Our results show that the length of exposure must be taken into account."
He is joined in his conclusions by Robert Belle, from the National Center for Social Research (CNRS) biological station in Roscoff (Finistere), whose team has been studying the impact of glyphosate formulations on sea-urchin cells for several years. This recognized model for the study of early stages of cancer genesis earned Tim Hunt the 2001 Nobel Prize in medicine. In 2002, the Finisterian team had shown that Roundup acted on one of the key stages of cellular division.
"This deregulation can lead to cancer," warns Robert Belle, who, to make himself understood, insists on summarizing the mechanisms of cancer genesis: during the division of a cell into two daughter cells, the two copies of genetic inheritance, in the form of DNA, may give rise to very numerous errors, up to 50,000 per cell. That's why repair mechanisms or natural cell death (apoptosis) are automatically set in motion. However, it happens that a cell escapes these alternatives (death or repair) and can perpetuate itself in an unstable form, potentially cancerous over the long term.
The Breton team has recently demonstrated (Toxicological Science, December 2004) that a "control point" for DNA damage was affected by Roundup, while glyphosate alone had no effect. "We have shown that it's a definite risk factor, but we have not evaluated the number of cancers potentially induced, nor the time frame within which they would declare themselves," the researcher acknowledges. A sprayed droplet could affect thousands of cells. On the other hand, "the concentration in water and fruits is lower, which is rather reassuring."
For the researcher, it's not necessarily a matter of banning the product - "Now it's for the public authorities to evaluate the benefits and the risks" - but it is important that users take every possible precaution, for themselves as well as for the public. "I've seen people in their underwear spray several square meters in a playground," he exclaimed, revolted.
"Such in vitro studies are not adequate for deducing the effects on people," however, insists Sophie Gallotti, coordinator of studies on contaminants at the Agence francaise pour la swcurite sanitaire des aliments (Afssa) [French Agency for Food Health Security]. The same sentiment is expressed by Remi Maximilien, toxicological expert at Afssa, for whom the sea-urchin experiment "shows a potential mechanism for cancer genesis that remains to be proved in human beings."
Monsanto is not impressed by these results. "It's not up to us to judge the interest of these publications, the validity of which we do not contest, but the interpretation," indicates Mathilde Durif, spokeswoman for the French subsidiary of the American giant. These results contradict sixty other available studies and "neither the European authorities nor the World Health Organization, nor the United Nations Food and Agricultural Organization (FAO) have classified this product as carcinogenic."
Glyphosate is, however, an active ingredient and "it is necessary to use it according to the recommended usage." A cautious attitude that seems slightly in contradiction with the firm's marketing efforts. And these are now already under attack by the Breton association, which reproaches Monsanto with making its product's "biodegradability" an advertising argument - one already judged to be a lie by the American legal system.