When microbiologist Bruce Hemming was hired two years ago to test breast milk samples for residues of the key ingredient in the popular weed-killer Roundup, Hemming at first scoffed at the possibility. Hemming, the founder of St. Louis-based Microbe Inotech Laboratories, knew that the herbicidal ingredient called glyphosate was not supposed to accumulate in the human body. Hemming, who previously worked as a scientist for Roundup maker Monsanto Co., now operates a commercial testing facility located just a few miles from Monsanto’s headquarters.
But Hemming said his lab’s testing did find residues of glyphosate in the samples of breast milk he received from a small group of mothers who were worried that traces of the world’s most popular herbicide might be invading their bodies. Food companies, consumer groups, academics and others have also solicited testing for glyphosate residues, fueled by fears that prevalent use of the pesticide on genetically engineered food crops may be contributing to health problems as people eat foods containing glyphosate residues.