Soybeans are sprayed in Iowa in 2013. Enlist Duo is a mixture of two chemicals that farmers have used separately for many years: glyphosate (also known as Roundup) and 2,4-D. The new formulation is intended to work hand-in-hand with a new generation of corn and soybean seeds that are genetically engineered to tolerate sprays of both herbicides. Charlie Neibergall/AP hide caption

toggle caption Charlie Neibergall/AP

A bottle of Monsanto's Roundup herbicide in a gardening store in Lille, France. A group convened by the European Food Safety Agency reviewed the available scientific data on the chemical, also known as glyphosate, and concluded that it probably does not cause cancer. Philippe Huguen/AFP/Getty Images hide caption

toggle caption Philippe Huguen/AFP/Getty Images

Central Illinois corn farmer Jerry McCulley refills his sprayer with the weedkiller glyphosate on a farm near Auburn, Ill. A new assessment of the chemical finds that the (uncertain) risks mainly affect the people who work with it or who come in direct contact with areas where it's applied. Seth Perlman/AP hide caption

toggle caption Seth Perlman/AP
Samuel LaHoz/Intelligence Squared U.S.

Corn farmer Jerry McCulley sprays the weedkiller glyphosate across his cornfield in Auburn, Ill., in 2010. An increasing number of weeds have now evolved resistance to the chemical. Seth Perlman/AP hide caption

toggle caption Seth Perlman/AP

Loved ones express their grief at the burial of Ramon Romero Ramirez in Chichigalpa, Nicaragua, January 2013. The 36-year-old died of chronic kidney disease after working in the sugar cane fields for 12 years. Ramirez is part of a steady procession of deaths among cane workers. Ed Kashi/VII hide caption

toggle caption Ed Kashi/VII

NPR thanks our sponsors

Become an NPR sponsor