A key ingredient in a weedkiller linked to cancer has also been found in loaves of bread and cereal.
An American man who blames his terminal cancer on Roundup weedkiller was last week awarded £226million in damages.
Traces of glyphosate were found in nearly two in three loaves of wholemeal bread in the UK, according to official research.
Glyphosate has also been found in Cheerios and Kellogg’s Corn Flakes in the US, as well as Doritos crisps and Ritz crackers.
The chemical is the world’s most widely used weedkiller, and use by British farmers has increased by a shocking 400 per cent in the last 20 years, according to the Soil Association, which campaigns for organic farming.
But despite a World Health Organisation agency judging it a ‘probable human carcinogen’, the EU relicensed its use for another five years last November.
Now a landmark court case, brought by Dewayne Johnson in California, has seen long-term use of Roundup blamed for his non-Hodgkin’s lymphoma.
Doctors say that the former school groundsman, 46, may only have a few months left to live.
A US jury awarded him £226million in damages on Friday after an eight-week trial.
They concluded that Roundup was the direct cause of his terminal blood cell cancer and that Monsanto – the company that makes them – had failed to warn him of the health risk from exposure.
Monsanto insists its products are safe and will appeal. However, the case raises new questions about the use of the chemical on food crops.
It was even found at low levels in Ben & Jerry’s ice creams by a study last year.
Official research suggests a third of UK cereal crops, such as wheat and barley, are sprayed with glyphosate.
It is used to kill weeds and as a drying agent on the plants, which makes them easier to harvest.
Its use was found to be at levels well below the safety limits set by European and American food watchdogs.
UK retailers, including Homebase and B&Q, are reviewing whether to continue selling the weedkiller to gardeners against the background of academic studies and consumer campaigns highlighting health concerns.
Glyphosate has also been linked to liver and kidney disease, infertility, and birth abnormalities.
Following the US court verdict, Labour’s deputy leader Tom Watson tweeted: ‘American jury finds glyphosate causes cancer. It’s the most used agricultural chemical ever. This finding has huge implications for the food chain.’
The Soil Association’s head of policy, Emma Hockridge, described the ruling as a ‘dramatic blow’ to the pesticide industry. She said: ‘We need to urgently change our systems of weed control to stop relying on herbicides.’
However, the National Farmers’ Union (NFU) said there is no need to review use of the pesticide.
Its deputy president, Guy Smith, also a livestock and arable farmer, said it had previously been ruled safe to use and ‘the opinion of a Californian jury’ shouldn’t change that.
Monsanto’s vice president Scott Partridge said hundreds of studies have shown glyphosate does not cause cancer.
‘It is completely and totally safe, and the public should not be concerned about this verdict,’ he said.