Insecticide from GE corn crops found in streams

The insecticidal protein Cry1Ab has been shown to leach from corn debris into adjacent streams (Photo: Pam Brophy)

A new study by Indiana’s University of Notre Dame has revealed that streams across the U.S. Midwest contain insecticides from adjacent fields of genetically engineered corn, even well after harvest. The transgenic maize (GE corn) in question has been engineered to produce the insecticidal protein Cry1Ab. Pollen, leaves and cobs from those plants enter streams bordering on the cornfields, where they are said to release Cry1Ab into the water.

Notre Dame ecologist Jennifer Tank and colleagues conducted a field survey of 217 stream sites in northwestern Indiana, six months after the corn harvest. 86 percent of those sites contained corn crop debris, and Cry1Ab was detected in the debris at 13 percent of those sites. That said, Cry1Ab that had presumably leached out of corn debris was detected in the water itself at 23 percent of the original 217 sites. The concentrations were not provided.

"Our study demonstrates the persistence and dispersal of crop byproducts and associated transgenic material in streams throughout a corn belt landscape even long after crop harvest," Tank stated.

The study also concluded that 91 percent of the 200,000 km (124,274 miles) of streams and rivers in Indiana, Iowa and Illinois are located within 500 meters (547 yards) of corn fields. Cry1Ab, a byproduct of the bacterium Bacillus thuringiensis, does already occur naturally in the environment – expansive crops of corn that produce it, needless to say, do not.