US government scientists have detected a weedkiller linked to cancer in an array of commonly consumed foods, emails obtained through a freedom of information request show. The Food and Drug Administration (FDA) has been testing food samples for residues of glyphosate, the active ingredient in ... widely used herbicide products, for two years, but has not yet released any official results. Documents obtained by the Guardian show the FDA has had trouble finding any food that does not carry traces of the pesticide. "I have brought wheat crackers, granola cereal and corn meal from home and there's a fair amount in all of them," FDA chemist Richard Thompson wrote to colleagues in an email last year regarding glyphosate. That internal FDA email ... is part of a string of FDA communications that detail agency efforts to ascertain how much of the popular weedkiller is showing up in American food. Glyphosate is best known as the main ingredient in Monsanto Co's Roundup brand. More than 200m pounds are used annually by US farmers. Thompson's detection of glyphosate ... will probably not be included in any official report. Separately, FDA chemist Narong Chamkasem found "over-the-tolerance" levels of glyphosate in corn, detected at 6.5 parts per million, an FDA email states. The legal limit is 5.0 ppm. An illegal level would normally be reported to the Environmental Protection Agency (EPA), but an FDA supervisor wrote to an EPA official that the corn was not considered an "official sample".