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.