The European Food Safety Authority (EFSA) says a recent study on the toxicity of genetically modified maize and a common herbicide is inconclusive. The study, published on 19 September, claimed to find that rats fed genetically modified maize developed tumors at a higher rate than control animals. The study received wide press attention, although it was criticized by many scientists for its design and its statistical analysis.
At the request of the European Commission, EFSA set up a task force to evaluate the study. That group released its initial report today, concluding that the study "is of insufficient scientific quality to be considered as valid for risk assessment." The study used too few rats, didn't include sufficient controls, and the paper didn't report all relevant endpoints, the task force says. It invited that the study's lead author, Gilles-Eric Séralini of the University of Caen in France, to provide the agency with more information by 12 October.
It's not clear whether Séralini will comply with that request. He told reporters last month that he would not accept any review of the study by EFSA. "It cannot be that those who authorized [Monsanto's GM maize variety] NK603 carry out the review of my data, because there would be a conflict of interest with their authority and their careers," he said at a 20 September press conference at the European Parliament in Brussels.
In Germany, the Federal Institute for Risk Assessment also found the study wanting. It said on Monday that "due to deficiencies in the study design and in the presentation and interpretation of the study results, the main conclusions of the authors are not supported by the data." It said it found no reason, based on the study, to reevaluate either the maize strain used in the study or the herbicide glyphosate. (The Séralini paper also reported that rats exposed to the herbicide glyphosate-better known as Roundup-in their drinking water developed tumors at a high rate as well.)
In France, the High Council for Biotechnology and the Agency for Food, Environmental and Occupational Health & Safety (ANSES) have been asked to look into the study. ANSES has announced that it will make its findings public on 20 October.