Even as the EU started giving ground on the issue of genetically modified foods at the WTO talks, a new study is showing that a widely used variety of GM corn leaves traces of toxin in the soil that can remain there indefinitely. The corn has been modified to produce a natural insecticide, the bacterium Bacillus thuringiensis, and the study, published in today’s issue of the journal Nature, found that the roots of the corn plants exude the toxin into the soil, where it can persist for at least 234 days. The researchers said that the toxin may affect a number of insects and organisms in addition to the caterpillars that it is intended to kill.