Laboratory rat feeds contaminated with pesticides and GMOs
New study throws doubt on findings of safety in pesticide and GMO studies. Claire Robinson reports
Laboratory rodent feeds are highly contaminated with pesticides, toxic metals, PCBs, and GMOs, according to a new study soon to be published in the journal PLOS ONE.
The study casts doubt on claims of safety drawn from hundreds of thousands of animal feeding trials performed for regulatory approvals of pesticides and GMOs.
For the study, the team of Prof Gilles-Eric Séralini at the University of Caen in France
analyzed the dried feed of laboratory animals sourced from 5 continents. These diets are commonly fed to rats used to test the safety of pesticides and GMOs. The study investigated 13 samples of rat feeds for traces of 262 pesticides, 4 heavy metals, 17 dioxins and furans, 18 PCBs and 22 GMOs.
The researchers found that all the feeds contained significant concentrations of several of these products at levels likely to cause diseases by disrupting the endocrine and nervous system of the animals. Considering all the contaminants measured, these diets, when consumed over a long-term experimental period, would be considered by standard measurements to pose a very high hazard to health.
For example, residues of glyphosate, used on 80% of GMO crops and widely used to “dry down” non-GMO crops before harvest, were detected in 9 of the 13 diets. Eleven of the 13 diets contained GMOs that are grown with large amounts of Roundup.
This is a problem for public health because regulators use tests on animals fed on these diets to assess the safety of any one pesticide or GMO by looking at the difference between the exposed animal and the controls. If the treatment (exposed) and control groups are both eating an uncontrolled assortment of pesticides or GMOs, any actual toxic effect arising from the pesticide or GMO under test, unless the effect is massive in size, will be lost amid the “noise” caused by the jumble of potentially and known toxic substances.