THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and colleagues,
RE: GM Corn in US Streams, Raises Questions About Health, Environmental Effects
A study, published in the journal Proceedings of the National Academy of Science, found that insecticidal protein from GM corn in the US has comtaminated streams in the American Mid-west where GM corn is largely grown.
The GM corn has a gene from the bacterium Bacillus thuriengensis (Bt) inserted into it to repel the corn borer beetle. The Bt gene produces a protein called Cry1Ab which has insecticidal properties.
The study analysed 217 streams in Indiana. It found dissolved Cry1Ab proteins from Bt corn present in stream water at nearly a quarter of the sites including headwater streams and up to 500 meters from the corn fields.
This latest finding adds to the growing body of evidence that corn crop byproducts can be dispersed throughout a stream network, and that the compounds associated with GM crops, such as insecticidal proteins, can enter nearby water bodies, says Emma Rosi-Marshall of the Cary Institute of Ecosystem Studies, one of the authors of the study.
So far scientists have not yet been able to determine how significant this is in terms of the risk to either human health or the wider environment. There is call for further research into how corn byproducts, including Cry1Ab insecticidal proteins, potentially impact non-target ecosystems, such as streams and wetlands.
With best wishes,
Third World Network
131 Jalan Macalister,
10400 Penang,
Malaysia
Email: twnet@po.jaring.my
Website: www.biosafety-info.net and www.twnside.org.sg
————————————————————————————————————
Item 1
GM maize ‘has polluted rivers across the United States’
Steve Connor, Science Editor
The Independent, 28 September 2010
An insecticide used in genetically modified (GM) crops grown extensively in the United States and other parts of the world has leached into the water of the surrounding environment.
The insecticide is the product of a bacterial gene inserted into GM maize and other cereal crops to protect them against insects such as the European corn borer beetle. Scientists have detected the insecticide in a significant number of streams draining the great corn belt of the American mid-West.
The researchers detected the bacterial protein in the plant detritus that was washed off the corn fields into streams up to 500 metres away. They are not yet able to determine how significant this is in terms of the risk to either human health or the wider environment.
"Our research adds to the growing body of evidence 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," said Emma Rosi-Marshall of the Cary Institute of Ecosystem Studies in Millbrook, New York.
GM crops are widely cultivated except in Britain and other parts of Europe. In 2009, more than 85% of American corn crops were genetically modified to either repel pests or to be tolerant to herbicides used to kill weeds in a cultivated field.
The GM maize, or corn as it is called in the US, has a gene from the bacterium Bacillus thuriengensis (Bt) inserted into it to repel the corn borer beetle. The Bt gene produces a protein called [Cry1Ab] which has insecticidal properties.
The study, published in the journal Proceedings of the National Academy of Science, analysed 217 streams in Indiana. The scientists found 86 per cent of the sites contained corn leaves, husks, stalks or cereal cobs in their channels and 13 per cent contained detectable levels of the insecticidal [Cry1Ab] proteins.
"The tight linkage between corn fields and streams warrants further research into how corn byproducts, including [Cry1Ab] insecticidal proteins, potentially impact non-target ecosystems, such as streams and wetlands," Dr Rosi-Marshall said.
All of the stream sites with detectable insecticidal proteins were located within 500 metres of a corn field. The ramifications are vast just in Iowa, Illinois, and Indiana, where about 90% of the streams and rivers – some 159,000 miles of waterways – are also located within 500 metres of corn fields.
After corn crops are harvested, a common agricultural practice is to leave discarded plant material on the fields. This "no-till" form of agriculture minimises soil erosion, but it then also sets the stage for corn byproducts to enter nearby stream channels.
————————————————————————————————————
Item 2
Insecticides from genetically modified corn present in adjacent streams
Stream ecosystems are tightly linked to agricultural fields and should be considered when adopting new agricultural technologies
Public release date: 27-Sep-2010
Contact: Lori M. Quillen
QuillenL@caryinstitute.org
845-677-7600 x233
Cary Institute of Ecosystem Studies
In a paper published this week in the Proceedings of the National Academy of Sciences, Cary Institute aquatic ecologist Dr. Emma Rosi-Marshall and colleagues report that streams throughout the Midwestern Corn Belt are receiving insecticidal proteins that originate from adjacent genetically modified crops. The protein enters streams through runoff and when corn leaves, stalks, and plant parts are washed into stream channels.
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.
Following an assessment of 217 stream sites in Indiana, the paper’s authors found 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.
Using these data, U.S. Department of Agriculture land cover data, and GIS modeling, the authors found that all of the stream sites with detectable Cry1Ab insecticidal proteins 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.
Rosi-Marshall comments, "Our research adds to the growing body of evidence 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."
After corn crops are harvested, a common agricultural practice is to leave discarded plant material on the fields. This "no-till" form of agriculture minimizes soil erosion, but it also sets the stage for corn byproducts to enter nearby stream channels.
Rosi-Marshall concludes, "The tight linkage between corn fields and streams warrants further research into how corn byproducts, including Cr1Ab insecticidal proteins, potentially impact non-target ecosystems, such as streams and wetlands." 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.
##########################
Other authors on the PNAS paper included first-author Dr. Jennifer L. Tank (University of Notre Dame) and Drs. Todd V. Royer (Indiana University), Matthew R. Whiles (Southern Illinois University), Natalie A. Griffiths (University of Notre Dame), Therese C. Frauendorf (University of Notre Dame), and David J. Treering (Loyola University Chicago).
The Cary Institute of Ecosystem Studies is a private, not-for-profit environmental research and education organization in Millbrook, N.Y. For more than twenty-five years, Cary Institute scientists have been investigating the complex interactions that govern the natural world. Their objective findings lead to more effective policy decisions and increased environmental literacy. Focal areas include air and water pollution, climate change, invasive species, and the ecological dimensions of infectious disease. Learn more at www.caryinstitute.org
——————————–
Item 3
Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape <http://www.pnas.org/content/early/2010/09/22/1006925107.abstract>
1. Jennifer L. Tank a ,1,
2. Emma J. Rosi-Marshall b ,2,
3. Todd V. Royer c,
4. Matt R. Whiles d,
5. Natalie A. Griffiths a,
6. Therese C. Frauendorf a, and
7. David J. Treering b
+ Author Affiliations
1. a Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556;
2. b Department of Biology, Loyola University, Chicago, IL 60660;
3. c School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405; and
4. d Department of Zoology and Center for Ecology, Southern Illinois University, Carbondale, IL 62901-6501
* ?2Present address: Cary Institute of Ecosystem Studies, Millbrook, NY 12545.
1. Edited by David Pimentel, Cornell University, Ithaca, NY, and accepted by the Editorial Board August 31, 2010 (received for review May 20, 2010)
Abstract
Widespread planting of maize throughout the agricultural Midwest may result in detritus entering adjacent stream ecosystems, and 63% of the 2009 US maize crop was genetically modified to express insecticidal Cry proteins derived from Bacillus thuringiensis. Six months after harvest, we conducted a synoptic survey of 217 stream sites in Indiana to determine the extent of maize detritus and presence of Cry1Ab protein in the stream network. We found that 86% of stream sites contained maize leaves, cobs, husks, and/or stalks in the active stream channel. We also detected Cry1Ab protein in stream-channel maize at 13% of sites and in the water column at 23% of sites. We found that 82% of stream sites were adjacent to maize fields, and Geographical Information Systems analyses indicated that 100% of sites containing Cry1Ab-positive detritus in the active stream channel had maize planted within 500 m during the previous crop year. Maize detritus likely enters streams throughout the Corn Belt; using US Department of Agriculture land cover data, we estimate that 91% of the 256,446 km of streams/rivers in Iowa, Illinois, and Indiana are located within 500 m of a maize field. Maize detritus is common in low-gradient stream channels in northwestern Indiana, and Cry1Ab proteins persist in maize leaves and can be measured in the water column even 6 mo after harvest. Hence, maize detritus, and associated Cry1Ab proteins, are widely distributed and persistent in the headwater streams of a Corn Belt landscape.
Footnotes
1To whom correspondence should be addressed. E-mail: tank.1@nd.edu.
Author contributions: J.L.T., E.J.R.-M., T.V.R., and M.R.W. designed research; J.L.T., E.J.R.-M., T.V.R., M.R.W., N.A.G., and T.C.F. performed research; J.L.T., E.J.R.-M., T.V.R., M.R.W., N.A.G., T.C.F., and D.J.T. analyzed data; and J.L.T., E.J.R.-M., T.V.R., M.R.W., N.A.G., and D.J.T. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission. D.P. is a guest editor invited by the Editorial Board.