June 13, 2013

expert reaction to press release from FotE and GM Freeze about glyphosate in urine

Friends of the Earth and GM Freeze press released the results of laboratory tests on the urine of 182 volunteers across Europe, which found traces of the weed killer glyphosate.

Prof Tom Sanders, Head of the Nutritional Sciences Research Division at Kings College London, said:

“Most samples were below the level of detection and the highest value found was less than 2 microgram (a millionth of a gram) per litre.  As most people excrete about 2.5 litres a day it would indicate the maximum intake was 5 micrograms, which is unlikely to be of any significance to health because it is 300 times lower than the level which might cause concern – even in the most vulnerable groups.”

Prof Denis Murphy, Professor of Biotechnology at Glamorgan University, said:

“There is a lot of unreliable junk ‘science’ and even more uninformed speculation about glyphosate on the internet – even though it is one of the safest weed control agents we have.

“This new study is impossible to critique as we are not given a sufficiently detailed protocol or experimental design etc so it cannot be classified as a scientific report.

“The issue of GM crops is a red herring as few if any glyphosate tolerant GM crops are grown in Europe – and even if livestock had been fed GM soy, any traces of the glyphosate would have been eliminated from their systems and even if any was present it would be in their gastrointestinal tract (offal) and not in the meat of the animals.

“It should also be noted that the recognised danger level of glyphosate is less than that of table salt!  In other words a far lower dose of salt is lethal to mammals compared to glyphosate.  So even if we are eating glyphosate it is relatively benign and not of major concern.”

Prof Alan Boobis, Professor of Biochemical Pharmacology at Imperial College London, said:

“The press release contains a number of inaccuracies.  The critical issue is the sensitivity of the analytical method.  The report mentions traces of the pesticides.  Given that low residues of glyphosate are permitted in food but are considered safe, it is not at all surprising that very low levels could be found in the urine of some people.  It would be necessary to determine if these suggested excessive intake.  But from what is presented here I don’t consider there is any cause for concern.”

Prof Chris Pollock, Aberystwyth University, said:

“It’s difficult to know where to begin with such an obviously political press release.  Without access to the full methodology that would be part of a peer-reviewed paper it is not possible to comment on the sampling procedures, the experimental design, the accuracy or the biological significance of these observations.  That is why peer-review has become the gold standard to permit scientists to evaluate new information appropriately.  Furthermore, I don’t believe that  these observations, even if correct, allow one to draw any conclusions about ways in which individuals might have been exposed to these substances.”

Dr Alison Haughton, head of the Pollination Ecology Group at Rothamsted Research, said:

“This is not good science – I cannot find where the methodology and results are published, and so it is impossible to assess the robustness of the work.  If FOE and GM Freeze want their work to have scientific credibility, and provide a genuine contribution to the debate on pesticide residues, then they should submit their work for publication in a peer-reviewed journal.  As it stands, this press release is completely insubstantial, it is not scientific, and cannot be taken seriously by anyone.”