GMO assessment in need of improvement

January 2012

Question marks over GM maize. Photo © Greenpeace / Martin Langer
A major issue highlighted by the GM food debate has always been what to debate. While Joe Public has deep misgivings spanning not only the immediate concerns, such as food safety, the scientific limitations, and the undue influence of commercial pressures, but about the long-term environmental, social and economic issues. The regulators have, so far, refused to deal with the breadth of questions that the people want answered.

Concerns raised are routinely dismissed with with assurances that GM food has been rigorously assessed. What this means is that some form of risk assessment has been carried out and, in terms of whatever parameters have been applied, the GMO has passed. The problem is that, with careful selection and application, these parameters can be made to tell you anything you want to know (see TORTURING THE RISK ASSESSMENT - GMFS News Archive, November 2010).


In the course of 2011, a stream of papers were published describing major flaws in the current risk assessment process for GMOs, and spelling out the improvements urgently needed.

One such study describes how America, the major driver of biotech development and adoption, set a very poor precedent for GMO risk assessment. When US scientists realised the economic potential of GM and the patent rights attached, they convinced politicians that the results of the new technology could have appeared in nature. Genetic engineering was then declared equivalent to conventional breeding methods, meaning a GMO was not a new organism with unforeseeable risks and did not require specific regulation. The US therefore opted to bend GMOs to fit its existing legal frameworks: plants which generate Bt-toxins are 'pesticides', fish which generate growth-hormones are 'drugs'; and other GM plant become a 'food additives' (Meyer).

Another team pointed out that:
“Despite over 10 years of large-scale commercial production of GM crops in at least five countries, no consensus on the applied ERA (Environmental Risk Assessment) methodologies, let alone agreed standardised testing procedures exist” (Hillbeck et al). It went on to suggest that a good place to start would be to select test-organisms which actually occur in the receiving environment, which are ecologically important for the sustainable production of the crop, and which will be subject to significant exposure. The method should select the most important problems and include “all possible effects, direct and indirect, cumulative and interaction effects”.
These authors are also very critical of the proposal that risk assessment of GMOs could be entirely a desk exercise based on data collected for other purposes without any acquisition of new data. In particular, stacked Bt insecticidal toxins are entering the market completely untested in their combined and probably interactive form.

Meyer suggests GMO risk assessment needs to be much wider in scope, to include factors such as the consideration of alternatives to GM, early warning systems for environmental impacts especially cumulative effects, global-scale risks, and safeguards for sustainable development.

Scientists in Uruguay can tell us why Meyers suggestions should be taken on board.

GM maize has been permitted for cultivation in Uruguay since 2003, but scientists have just ascertained that, where the proximity and sowing dates of the GM and non-GM crops are favourable, cross-pollination happens.

This discovery made them pause for thought, and they soon realised some uncomfortable truths.

For example, the tracking of gene movement is highly dependent on the experimental design used. Also, the future promises ever-increasing contamination. This is because gene movement becomes greater as the crop area or number of GM fields increases. It's also because, while first-generation GM plants have one GM event on one chromosome which is therefore spread in only half the pollen, future GM plants will be stacked with a variety of genes on different chromosomes and produce pollen all of which will contain an assortment of engineered DNA constructs.

What this all adds up to is that the 'risk' attached to a GM crop is inevitably an escalating potential for harm: this year's GM risk assessment may be irrelevant to next year's GM problems.

A major point which keeps coming up is that, not only does the risk assessment need to be more holistic, but “the decision framework more responsive to the specific social and economic situations in different countries”.

A prime example of the need for this was also published in 2011.

The US scientist who discovered transgenes in Mexican maize landraces (a finding since verified by a number of independent teams), and drew fire from a 'shoot-the-messenger' campaign within the scientific establishment, has co-authored a brief on the risk assessment of GM maize in Mexico.

Since the question of whether transgenes will contaminate Mexican landraces is no longer in doubt, the pertinent question is what will be lost if it is allowed to continue. The risk can only be assessed within the unique Mexican context. Mexico is the centre of origin of maize: it is the natural gene-bank for maize diversity and an irreplaceable resource for future breeding programmes. Moreover, erosion of landrace diversity could lead to a catastrophic erosion of the local knowledge needed for its cultivation. Maize is the staple of the Mexican diet and has important social, economic and cultural significance throughout the country. A risk assessment focusing on the toxicity of any single artificial, isolated protein is, in this context, ludicrous.

As the authors point out, a consideration of alternative approaches is clearly called for.

In Europe, shortcomings in the risk assessments for GMOs, such as data gaps and uncertainties, have led to “considerable dispute amongst member states”. In response to criticism, the European Food Safety Authority (EFSA) has been updating its guidance on environmental risk assessment in collaboration with all stakeholders. The new EFSA guidance includes substantial modifications, such as the addition of long-term effects, field trials, and the receiving environment. However, in December 2011, the Authority repeated its favourable 2005 opinion on GM maize 1507, genetically transformed to generate a insecticidal Bt-toxin. The only difference six years on, after a stack of complaints and much head-scratching, is that the EFSA acknowledges that the insecticidal properties of the GM maize will pose a threat to many common and iconic butterflies already under threat from agricultural practises.

Like Hillbeck et al., GM Freeze has drawn attention to the lack of toxicity data on the 'receiving environment' of maize 1507. There are:
  • “Insufficient data for all species of moths and butterflies likely to be exposed to the GM toxin, known as Cry1F, from 1507 maize”
  • “Almost complete lack of data on the sub-lethal impacts of Cry1F on non-target moths and butterflies”
Also like Hillbeck et al., Testbiotech has pointed out that vital parts of the EFSA risk assessment of maize 1507 are based on data cllected for other purposes: “analogues and conclusions are drawn from other Bt toxins (Cry1Ab) which differ in their mode of action as well as their effect.”

OUR COMMENT

One or two things to bear in mind next time you hear the claim that GM crops have been assess and found 'safe':
  • All need for risk assessment was dismissed from the outset under commercial pressure, and since then everyone's being trying to play catch-up. But there's still a very long way to go
  • There's no agreement on what needs to be included in a GM risk assessment
  • The organisms actually exposed to a GMO aren't tested (that includes humans)
  • The bigger and future pictures have been ignored
  • Contrary to the usual use of risk assessments (and their prime purpose), acknowledgement of a GM risk carries no obligation to do anything about it. 
GM assessed and found safe? Humbug!

SOURCES
  • Harmut Meyer, 2011, Systemic risks of genetically modified crops: the need for new approaches to risk assessment, Environmental Sciences Europe, 23:7
  • Angelika Hillbeck et al., 2011, Environmental risk assessment of genetically modified plants - concepts and controversies, Environmental Sciences Europe, 23:13
  • Marion Dolezel et al., 2011, Scrutinizing the current practice of the environmental risk assessment of GM maize application for cultivation in the EU, Environmental Sciences Europe, 23:33
  • Pablo Galeano et al., 2011, Cross-fertilization between genetically modified and non-genetically modified maize crops in Uruguay, Environmental Biosafety Research
  • David Quist and Georgina Catacora-Vargas, Transgenes in Mexican Maize, Ten Years On: Still not addressing the right questions on risks, Biosafety Brief 2011/04
  • Andreas Bauer-Panskus and Christoph Then, Opinion concerning the application for marketing approval of genetically modified maize 1507, TEST Biotech (Institute for Independent Risk Assessment in Biotechnology), April 2010
  • EFSA Admits Bt Maize Threat to Butterflies, Gives Green Light Regardless, GM Freeze Press Release, 18.12.11

No comments:

Post a Comment

Thanks for your comment. All comments are moderated before they are published.