Flaws in Risk Assessment of Bt 11 Maize


On 20 May 2005 European Food Safety Authority (EFSA) delivered a positive opinion on Syngenta's application for insect resistant genetically modified (GM) maize Bt11.

The notifier (now Syngenta) applied for the approval to cultivate Bt11 maize in the European Union. Bt11 produces the Bt toxin Cry1Ab against Lepidoptera (moths and butterflies) to protect maize against the two insect pests European stem borer (ECB, Ostrinia nubilalis) and Mediterranean stem borer (MCB, Sesamia nonagrioides). In addition, Bt11 is herbicide-tolerant against the glufosinate-ammonium (BASTA, Liberty).The notifier claims that Bt11 will not be marketed for its herbicide tolerance, but in other countries, such as the USA and Canada, Bt11 is marketed for both GM traits.

The application contains almost no original data about risk assessment studies, and in several cases the summaries make clear that the few studies that were undertaken lack scientific relevance for growing Bt11 in the field. They lack any study of medium or long-term effects, effects on European species (especially European butterflies) and studies on impacts on the soil biota. Even Member States stated that it would not be possible to draw positive recommendations from this limited data. Information about the actual insert, about the insertion site and possible additional, unintended inserts are classified as confidential business information, thereby making it impossible for third parties to undertake an independent assessment.

Bt11 should not be grown in the EU because:
The notification lacks original data that would enable an independent assessment to be made of the studies undertaken and their results.
* The non-target studies are insufficient to enable a risk assessment to be undertaken, while the scientific literature gives enough indications of adverse effects of Bt11 on non-target organisms, including multitrophic interactions between plants, herbivores and pests. Effects on soil organisms have not been studied at all.
* There are unexplained irregularities in the molecular data discovered by independent scientists, including rearrangements and possible contamination with Bt176. A summary of a (otherwise as CBI classified) sequencing acknowledges the integration of several pieces of vector backbone DNA, but does not clarify the other irregularities found earlier in an independent study.The site of the insertion is a region where
interruptions are likely to interfere with the basic metabolism of the GM plants.
* There are no sufficient data from feeding and toxicity studies.
* Bt11 is also tolerant to the herbicide glufosinate (brand name Liberty, Basta).This transgenic trait has not undergone any risk assessment, yet can have environmental effects; either directly or through changes in agricultural practices.
* The monitoring plan is inadequate. As even the EFSA points out, not enough attention is given to resistance development and adverse effects on non-target organisms. As well as farmers who are supposed to fill in questionnaires, but who might have conflicting interests, only a vague list of existing networks (including seed producers, and actors in the food and feed industry) is given without information on how such a monitoring exercise would work and whether theseorganisations are interested in participating. It has been acknowledged by the EFSA that some of these organisations lack the necessary scientific expertise.