The approval process for glyphosate herbicide is disputed because the commercial formulations contain co-formulants, which are more toxic than glyphosate alone.
We measured the endocrine disruptive effects of co-formulants of six glyphosate herbicides. We did this by measuring the activity of aromatase, a key enzyme for the balance of sex hormones, in human placental cells, using a method validated by the OECD to assess endocrine disruptors.
The aromatase activity was significantly decreased both by the co-formulants alone and by the formulations, from doses 800 times lower than the agricultural dilution, while glyphosate alone only showed such an effect from one-third of the agricultural dilution.
This new study, published in the International Journal of Environmental Research and Public Health, demonstrates for the first time that the endocrine-disrupting effects of glyphosate-based herbicides are not only attributable to glyphosate, the declared active ingredient, but above all to the co-formulants.
This research questions the definition of the acceptable daily intake (ADI) for pesticides, because the ADI is calculated based on toxicity testing of only the declared active ingredient. Yet glyphosate is never used alone, but only with its co-formulants. Therefore we recommend that the acceptable daily intake of pesticides is calculated from toxicity tests on the commercial formulations.
Published in International Journal of Environmental Research and Public Health:
Co-Formulants in Glyphosate-Based Herbicides Disrupt Aromatase Activity in Human Cells below Toxic Levels (2016) DOI:10.3390/ijerph13030264
The authors : Nicolas Defarge, Eszter Takacs, Veronica Laura Lozano, Robin Mesnage, Joel Spiroux de Vendomois, Gilles-Eric Seralini and Andras Szekacs