THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and Colleagues
Co-formulants in glyphosate-based herbicides demonstrate endocrine-disrupting effects on human cells
Reproductive health is influenced by environmental toxicants, including pesticides. The declared active ingredients (dAI) of pesticide formulations are not applied in their isolated form in agricultural use. Other substances (co-formulants) are also added in order to modify the physico-chemical properties or to improve penetration or stability of the dAIs. The identity of the co-formulants (declared as inert) is generally kept confidential. Moreover, they are not used in medium or long term in vivo toxicity tests of pesticides on mammals for the establishment of their acceptable daily intake (ADI).
Glyphosate-based herbicides (GBHs), such as Roundup, are the most frequently used worldwide, particularly with the advent of herbicide-tolerant genetically engineered crops. Their residues are common contaminants of ground and surface water and in food and feed. Studies have shown that GBHs and their co-formulants, such as polyethoxylated tallow amine (POEA), are more toxic than glyphosate alone.
A new study (abstract below) has tested the cellular endocrine-disrupting effects of co-formulants in GBHs below toxic levels, both alone and in formulations (mixtures of co-formulants and active ingredient), in comparison to glyphosate. The endocrine-disrupting effects of these compounds were measured on aromatase activity, a key enzyme in the balance of sex hormones, below the toxicity threshold. Aromatase activity was decreased both by the co-formulants alone and by the formulations, from concentrations 800 times lower than the agricultural dilutions; while glyphosate exerted an effect only at one-third of the agricultural dilution. None of the co-formulants tested were found to be inert in human cells.
The study has shown, for the first time, that below their toxicity thresholds, the co-formulants themselves can act as endocrine-disrupting chemicals. The results confirm that the distinction between “active ingredient” and “inert compound” is a regulatory assertion with no toxicological ground and that the ADI for glyphosate is unreliable in terms of assessing the risks of the complete commercial formulations that people are actually exposed to.
The study recommends that the physiological effects of co-formulants be more thoroughly tested and declared; also that the calculation of the ADI for pesticides should be based on toxicity tests of the commercial formulations rather than solely of the declared active ingredient.
With best wishes,
Third World Network
131 Jalan Macalister
10400 Penang
Malaysia
Website: https://biosafety-info.net/ and http://www.twn.my/
To subscribe to other TWN information services: www.twnnews.net
CO-FORMULANTS IN GLYPHOSATE-BASED HERBICIDES DISRUPT AROMATASE ACTIVITY IN HUMAN CELLS BELOW TOXIC LEVELS
Nicolas Defarge, Eszter Takác, Verónica Laura Lozano, Robin Mesnage, Joël Spiroux de Vendômois, Gilles-Eric Séralini, and András Székács
http://www.mdpi.com/1660-4601/13/3/264
Abstract
Pesticide formulations contain declared active ingredients and co-formulants presented as inert and confidential compounds. We tested the endocrine disruption of co-formulants in six glyphosate-based herbicides (GBH), the most used pesticides worldwide. All co-formulants and formulations were comparably cytotoxic well below the agricultural dilution of 1% (18–2000 times for co-formulants, 8–141 times for formulations), and not the declared active ingredient glyphosate (G) alone. The endocrine-disrupting effects of all these compounds were measured on aromatase activity, a key enzyme in the balance of sex hormones, below the toxicity threshold. Aromatase activity was decreased both by the co-formulants alone (polyethoxylated tallow amine—POEA and alkyl polyglucoside—APG) and by the formulations, from concentrations 800 times lower than the agricultural dilutions; while G exerted an effect only at 1/3 of the agricultural dilution. It was demonstrated for the first time that endocrine disruption by GBH could not only be due to the declared active ingredient but also to co-formulants. These results could explain numerous in vivo results with GBHs not seen with G alone; moreover, they challenge the relevance of the acceptable daily intake (ADI) value for GBHs exposures, currently calculated from toxicity tests of the declared active ingredient alone.