A crop circle X marks location of commercial GE maize fields in France. French courts want the locations kept secret.
The study, carried out by French scientific research institute CRIIGEN on the results of rat feeding trials using a GE maize made by biotech firm Monsanto, highlights 60 significant differences between the rats that were fed the GE maize and those fed normal maize (all for 90 days). The first group showed differences in their kidney, brain, heart and liver measurements, as well as significant weight differences. These could be warning signs of toxicity, but have not been further investigated.
"Greenpeace is deeply concerned that genetically engineered crops and foods are getting the EU green light for sale despite alarming health anomalies occurring in test animals over very short test periods. We will be faced with eating these foods for years," said Marco Contiero policy adviser on GMOs at Greenpeace European Unit.
The Monsanto maize, known as NK603 maize, has been engineered to tolerate Monsanto's own herbicide. Approved for import for use in human food and animal feed in 2004, it is currently being tested for cultivation in field trials in Europe.
The scientists at CRIIGEN analysed Monsanto's own test results, which had informed the EU food safety authority's decision to approve the maize for sale. CRIIGEN's report  suggests that a far more thorough investigation is necessary.
Neither Monsanto nor the scientific committees consulted on the feeding trials disputed the differences found in the test animals compared to the control group. However, they dismissed the results as "not of biological significance". The CRIIGEN study questions that conclusion.
"It is alarming that a company which produces a genetically-engineered crop not only gets to design and conduct the safety tests of its own product, but also to analyse the results. The lack of any independent scrutiny of test data suggests that Europe's risk assessment procedure is overlooking the threats and not assessing risks at all, just rubberstamping company dossiers," said Marco Contiero.
This is the second such case: another Monsanto maize, known as MON863, subject of a peer-reviewed scientific study published in March 2007, also showed signs of toxicity of liver and kidney in rats fed with this maize over a period of three months.
Professor Gilles-Eric Séralini of CRIIGEN, the University of Caen and the French state commission on biotechnology (Commission du Genie Biomoleculaire, CGB) said: "The statistical analysis should be repeated by independent experts and the crude data put on a website for the scientific community to be involved. Further testing should always be carried out if the analyses of the data do not result in a clear outcome."
Greenpeace is campaigning for the withdrawal from the market of NK603 maize, pending further investigation and a re-evaluation of Monsanto's trials, and for the suspension of all genetically engineered product and crop authorisations until the current EU risk assessment system is reviewed.
The CRIIGEN report is available now from Professor Séralini, 40 rue de Monceau, 75008 PARIS, or by e-mail from Katharine Mill, . It will be posted on the CRIIGEN website in the coming days.