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article imageBacteria protein inserted into GM corn found in US waterways

By Stephanie Dearing     Oct 26, 2010 in Environment
The Cary Institute for Ecosystem Studies published research findings in late September showing an insecticidal protein, called Cry1Ab, inserted into genetically modified corn to fight insect predation, was found in US waterways.
The Cary Institute announced the publication of their research results in late September, but only a small handful of media outlets picked up on the story. The researchers found streams near corn fields containing corn genetically modified to contain Bt contained the pesticidal bacteria, and they were able to determine that the pesticide contamination came directly from the GM corn. The results of the research, Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape was published in September by Proceedings of the National Academy of Sciences of the United States of America (PNAS).
Monsanto acknowledged the research in a simple statement that said "On September 27, 2010, an article in the Proceedings of the National Academy of Sciences (PNAS) reported the presence of corn leaves and other plant material in streams close to corn fields, and detection of the protein Cry1Ab which is present in Bt corn. Previous studies have already reported this observation.
The results of this study are neither new nor surprising. Cry1Ab protein is expected to be present in degrading corn residues in aquatic systems near corn fields. The study did not suggest that concentrations of Cry1Ab detected have any effect on non-target organisms.
Monsanto takes the safety and stewardship of our products seriously. Our scientists review every new publication related to the safety of our products, promptly and carefully."
Bt or "Bacillus thuringiensis ... is a naturally occurring, soil borne organism that has gained recent popularity for its ability to control certain insect pests in a natural, environmentally friendly manner." Bt corn first was planted in 1996 in the USA, and since then, said a study by Indiana University researchers, has been enormously beneficial for farmers.
While Bt itself appears to be safe for many animals, there have been concerns raised about transgenic Bt -- the Bt inserted into the genes of plants since then, according to a 1998 research paper prepared by scientists from the Swiss Federal Research Station for Acroecology and Agriculture. That paper said a definitive conclusion on the safety of transgenic Bt was not possible at the time. Many subsequent studies have concluded that transgenic Bt does not pose a threat.
However, some studies have shown the protein Cry1Ab poses a threat to some living creatures, usually called "non-target organisms," such as butterflies and honey bees reported The Bioscience Resource Project.
Leaving aside safety issues, the real issue, said lead researcher for the Cary Institute report, Dr. E.J. Rosi-Marshall was the fact that “... corn crop byproducts can be dispersed throughout a stream network, and that the compounds associated with genetically-modified crops, such as insecticidal proteins, can enter nearby water bodies.”
As the researchers point out, "... Genetically-modified plants are a mainstay of large-scale agriculture in the American Midwest, where corn is a dominant crop. In 2009, more than 85% of U.S. corn crops were genetically modified to repel pests and/or resist herbicide exposure. Corn engineered to release an insecticide that wards off the European corn borer, commonly referred to as Bt corn, comprised 63% of crops. The tissue of these plants has been modified to express insecticidal proteins, one of which is commonly known as Cry1Ab."
The researchers assessed 217 streams in Indiana, finding "... dissolved Cry1Ab proteins from Bt corn present in stream water at nearly a quarter of the sites, including headwater streams. Eighty-six percent of the sampled sites contained corn leaves, husks, stalks, or cobs in their channels; at 13% of these sites corn byproducts contained detectable Cry1Ab proteins. The study was conducted six months after crop harvest, indicating that the insecticidal proteins in crop byproducts can persist in the landscape."
More than that, however, the researchers said the streams with the Cry1Ab "... were located within 500 meters of a corn field ... Furthermore, given current agricultural land use patterns, 91% percent of the streams and rivers throughout Iowa, Illinois, and Indiana —some 159,000 miles of waterways—are also located within 500 meters of corn fields."
Ultimately, why should anyone care about a substance that has largely been scientifically proven to be save for most living beings? As the Cary Institute points out, "... These corn byproducts may alter the health of freshwaters. Ultimately, streams that originate in the Corn Belt drain into the Mississippi River and the Great Lakes."
Research on the effects of Cry1Ab on waterways and animals living in streams, rivers and lakes is lacking. However, early research conducted in Canada showed some accumulation of Cry1Ab in fresh water mussels. No one knows what effects this contamination might have.
More about Corn, Cary institute ecosystem studies, Insecticides, Cry1ab
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