ARGENTINIAN molecular biologist Andres Carrasco, whose work on the pesticide glyphosate became a major headache for biotechnology conglomerate Monsanto, died this weekend aged 67.

Mr Carrasco, who worked at the University of Buenos Aires and was past president of his country’s science council, was a widely published expert in embryonic development.

His 2010 study on glyphosate thrust him to international prominence, posing a major public-relations challenge to the US transnational corporation.

Glyphosate is the key ingredient in Monsanto’s Roundup brand of pesticides, which have combined with genetically modified “Roundup-Ready” plants to dramatically increase the spread of industrial agriculture round the world.

The US Environmental Protection Agency has labelled it reasonably safe to use if applied properly.

However, Mr Carrasco decided to test the impact of glyphosate on frog and chicken embryos after hearing reports of increasing birth defects in farming communities after genetically modified crops were approved for use in Argentina.

His team’s study, published in the peer-reviewed Chemical Research in Toxicology journal, found that injecting very low doses of glyphosate into embryos can change levels of retinoic acid, causing the same sort of spinal defects that doctors are increasingly registering in communities where farm chemicals are ubiquitous.

Retinoic acid, a form of vitamin A, is fundamental for keeping cancers in check and triggering genetic expression, the process by which embryonic cells develop into organs and limbs.

“If it’s possible to reproduce this in a laboratory, surely what is happening in the field is much worse,” he said, arguing the necessity to “put this under a magnifying glass.”

Monsanto dismissed his results as “not surprising given their methodology and unrealistic exposure scenarios.”

Company spokesman Thomas Helscher said that those methods were “relatively new” and that scientists don’t yet understand “how to translate genetic modulations into predictions of adverse outcome.”

He said that injecting embryos with pesticides was “less reliable and less relevant for human risk assessments” than methods the industry uses.