To accommodate high levels of Roundup residues in GM soya, limits were raised 200-fold – with no scientific justification and ignoring growing evidence of toxicity. What Monsanto calls ‘extreme levels’ are now the norm – but only in GM crops.
Food and feed quality are crucial to human and animal health.
Quality can be defined as sufficiency of appropriate minerals, vitamins and fats, etc. but it also includes the absence of toxins, whether man-made or from other sources.
Surprisingly, almost no data exist in the scientific literature on herbicide residues in herbicide tolerant genetically modified (GM) plants – even after nearly 20 years on the market.
In research recently published by our laboratory (Bøhn et al. 2014) we collected soybean samples grown under three typical agricultural conditions: organic, GM, and conventional (but non-GM). The GM soybeans were resistant to the herbicide Roundup, whose active ingredient is glyphosate.
All the GM samples had Roundup residues .
We tested these samples for nutrients and other compounds as well as relevant pesticides, including glyphosate and its principal breakdown product, Aminomethylphosponic acid (AMPA).
All of the individual samples of GM-soy contained residues of both glyphosate and AMPA, on average 9.0 mg/kg. This amount is greater than is typical for many vitamins.
In contrast, no sample from the conventional or the organic soybeans showed residues of these chemicals (see Fig. 1 – above right).
This demonstrates that Roundup Ready GM-soybeans sprayed during the growing season take up and accumulate glyphosate and AMPA. Further, what has been considered a working hypothesis for herbicide tolerant crops, i.e. that, as resistant weeds have spread:
“there is a theoretical possibility that also the level of residues of the herbicide and its metabolites may have increased” (Kleter et al. 2011) is now shown to be actually happening.
A similar situation can be found for other pesticides. Mesnage et al. (2014) found that 8 out of 9 tested pesticides were more toxic than their declared active principles.
This means that the Accepted Daily Intake (ADI) for humans, i.e. what society finds ‘admissible’ regarding pesticide residues may have been set too high, even before potential combinatorial effects of different chemical exposures are taken into account.
For glyphosate formulations (Roundup), realistic exposure scenarios in the aquatic environment may harm non-target biodiversity from microorganisms, invertebrates, amphibians and fish, (reviewed in Annett et al. 2014) – indicating that the environmental consequences of these agrochemicals need to be re-assessed.
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