Is there any real reason to stop GM maize cultivation?
Any new plant variety will have an impact on the environment and possibly on food safety. It is therefore inappropriate to consider the significance or safety of GMOs per se, no more than any other type of plant obtained by classical breeding techniques. Hence, any new plant variety, genetically modified or not, should thus be considered only on a case-by-case basis.
Plant varieties obtained either by classical breeding or by gene transfer share a similar level of risk, which is low in both cases. A plant variety resistant to some insects and obtained by classical breeding would bear essentially the same risks as a GM variety with the same insect resistant characteristics. However, the current bio-safety rules oblige the latter to be subjected to stricter testing than the former.
GMOs may lead to problems if the species or the varieties disseminate spontaneously. This risk could be even higher if the modification in the GM plants confers a selective advantage under normal cultivation conditions. Such GMOs are not authorized. For example, herbicide-tolerant rapeseed has not been approved in France by the Commission du Génie Biomoléculaire (CGB) nor in the UE by the European Food Safety Authority (EFSA). The cultivation of conventional maize and of insect-resistant GM maize does not raise any particular risk of dissemination, since this species does not disseminate spontaneously. Numerous experiments, performed on several continents, have led to the definition of the required distance between two maize fields necessary for the coexistence of different production methods, which also requires acceptance of trace amounts of GMO. Legal threshold levels remain to be defined. These results are in agreement with previous isolation practices allowing high purity seeds to be produced.
Maize has been cultivated and eaten by humans for thousands of years without any negative effect for animal or human health, despite the numerous genetic modifications incurred during classical genetic selection. The insecticide active compound present in GM maize has also been exploited for decades by conventional agriculture, organic agriculture and gardeners, by spreading spores from the bacteria Bacillus thuringiensis (which contains several toxins termed Bt), without any toxic or allergic response being observed. Specialized committees throughout the world agree on this point. Therefore, the association of maize and the active compounds of Bt toxins has a negligible chance of creating varieties containing substances deleterious for consumer health and no such events have been observed. On the contrary, it has been shown that Bt maize is less susceptible to pathogenic fungal infections than conventional maize and therefore contains lower levels of mycotoxins, which are carcinogenic substances.
In addition, the potential environmental effects of GM Bt maize, in particular on non-target insects, have already been widely studied. Without ruling out the interest of follow-up studies, the available studies consistently indicate that GM Bt maize has a lesser environmental impact than the authorized insecticide treatment.
The cohabitation of conventional, GM and organic maize cultivation is therefore possible. It has been a reality for years in about twenty countries without any particular problem.
A moratorium on the cultivation of GM maize approved by the EU is therefore not scientifically justified as it would be based only on imaginary or false uncertainties concerning environmental or food safety. It would bring no new knowledge that could reduce the hypothetical risks that could be generated by the cultivation and the consumption of GM Bt maize. Therefore, such a moratorium would be in contradiction with the precautionary principle.