When testing the firm’s top brand weed killer the rats showed similar symptoms.

The French government has asked its health and safety agency to assess the study and had also sent it to the European Union's food safety agency, Reuters reports.

"Based on the conclusion…, the government will ask the European authorities to take all necessary measures to protect human and animal health, measures that could go as far as an emergency suspension of imports of NK603 maize in the European Union," the French health, environment and farm ministries said in a joint statement.

Researchers from the University of Caen found that rats fed on a diet containing NK603 – a seed variety made tolerant to amounts of Monsanto's Roundup weedkiller – or given water mixed with the product, at levels permitted in the United States – died earlier than those on a standard diet.

The research conducted by Gilles-Eric Seralini and his colleagues, said the rats suffered mammary tumors, as well as severe liver and kidney damage. The study was published in the journal of Food and Chemical Toxicology and presented at a news conference in London.

Fifty percent of male and 70 percent of female rats died prematurely, compared with only 30 percent and 20 percent in the control group, said the researchers.

Combination image of two pictures featuring rats with tumors after they were fed a diet of genetically modified (GM) maize produced by US chemical giant Monsanto (AFP Photo / Criigen)

Monsanto spokesman, Thomas Helscher, said the company would review the study thoroughly but stated that other scientific studies had proved the biotech crops’ safety.

Some scientists however criticized the French researchers’ statistical methods and the use of a particular type of rat, saying the albino Sprague-Dawley strain of animal had a tendency to develop cancers.

But despite skepticism, the study draws attention to controversy surrounding genetically modified crops and the US biotech giant Monsanto.

Michael Antoniou, a molecular biologist at King’s College London – who acted as an adviser to Seralini's team – told reporters that the study stresses the “need to test all GMO crops in two-year lifelong studies”.

“I feel this data is strong enough to withdraw the marketing approval for this variety of GMO maize temporarily, until this study is followed up and repeated with larger number of animals to get the full statistical power that we want,” he said as quoted by Reuters.

Last Friday France said it will uphold a ban on genetically modified crops produced by the Monsanto. The move came as President Francois Hollande pushed his plan to put the environment back at the top of the international agenda.

In the wake of the publication, Jose Bove, vice-chairman of the European Parliament’s commission for agriculture, called for an immediate suspension of all EU cultivation and import authorizations of genetically modified crops.

“This study finally shows we are right and that it is urgent to quickly review all GMO evaluation processes,” he said following the announcement of the research.

While being widely used in the United States, GMO crops have been less popular among European consumers, due to concerns about its impact on people’s health and the environment.

In California, opponents of genetically engineered food are fighting to have it removed from the food supply. They are also pushing to pass Proposition 37, a law that would legally require genetically modified foods to be labeled as such. Monsanto stands opposed to such a proposal and has donated over $4.2 million to lobby against it.

Agriculturalists across America have previously tried to take the biotech giant to court over charges stemming from their lab-made corn GMOs. Over 2,000 farmers have petitioned the US government to more thoroughly investigate the impact that genetically modified corn crop from Monsanto will have on the country.

As RT reported before, Monsanto wants to plant a corn variant across America’s Midwest that will be resistant to a powerful pesticide produced with 2,4-D, the same compound crucial to the make-up of the notorious Vietnam War-era killer Agent Orange. If approved, the new corn will be able to thrive as farmers douse their fields in the chemical, killing off unwanted weeds in the process, while at the same time subjecting Americans to a pesticide linked to cancer risks.

Source: RT.com - Published: 20 September, 2012