Sep 27, 2011
Germany’s organic food industry association questions risk assessments of GM plants
A study with omissions
In the spring, Germany’s organic food industry association, BÖLW, collected over 100,000 signatures for a petition demanding an end to authorisations of GM plants. Timed to coincide with the consultation in the Bundestag’s Petitions Committee on 26 September 2011, the BÖLW published a new study that mentions “massive gaps in the risk assessment of GM plants”. However, the study itself contains some notable gaps: the current level of scientific knowledge on many aspects of the risk assessment of GM plants has been misrepresented, reduced or omitted altogether.
Felix Prinz zu Löwenstein, Chairman of the BÖLW, before the Bundestag’s Petitions Committee
The BÖLW is calling for approvals of GM plants to be halted until new authorisation procedures are in force in the EU. It bases its demands on a study entitled “Risiken mit amtlichem Siegel” (risks with a seal of authority) that it commissioned from former Greenpeace officer Christoph Then. If the BÖLW had its way, the precautionary principle enshrined in the EU would be extended so far that the work involved in authorising genetically modified plants would become unmanageable.
For example, whereas a GM plant is currently assessed to see whether certain effects (e.g. impacts on certain insects) or plant substances (e.g. vitamin levels) are within the range found in commercially available conventional plant varieties, the BÖLW is calling for every GM plant to be “systematically assessed for its genetic stability and interaction with the environment under various defined environmental conditions in a kind of ‘stress test’”. If this did become a legal requirement, authorisation – which in the EU is already an expensive, protracted procedure – would become completely unattractive for companies and plant breeders. To allow the safety of a GM plant or food and feed produced from it to be assessed, applicants would be forced to measure data using immense scientific and financial resources that would not provide much more in the way of substantial findings than what we have today.
The study is obviously intended to bring about a ban on GM plants in Europe through the back door by means of extreme authorisation requirements. It therefore makes sense to portray the current risk assessment procedure as much less effective than it is. In a number of places, the study claims that GM plants have been approved in cases where there were knowledge gaps, and therefore insufficient basis for a risk assessment.
For many of the alleged knowledge gaps in the risk assessment of GM plants mentioned in the report, there are in fact indisputable research findings available because issues relating to the environmental and product safety of GM plants have been the subject of intensive research all over the world for years. The results of numerous research projects have been published in scientific journals. For instance, US ecologists Michelle Marvier and Peter Kareiva published a metastudy in which they evaluated 42 studies on the potential impacts of Bt maize and Bt cotton on non-target organisms.
Biosafety research has also been practised in Germany for more than 20 years. The German Federal Ministry of Education and Research (BMBF) in particular and individual German states have carried out more than 130 research projects in recent years to study the ecological impacts of cultivating various GM crops.
The following examples compare some of the claims in the BÖLW study on Bt maize with the actual state of knowledge and research.
Does Bt maize accumulate in the soil? Several research projects have so far failed to find any indication that the Bt protein might accumulate in the soil.
Earthworms: Even sensitive soil organisms are not affected.
BÖLW study claim: Bt toxins can be excreted by the roots of GM plants and remain on the field for months. This could be harmful to soil life. However, it is not known how long most Bt toxins survive in the soil and what effect they have.
Current state of research and knowledge: When genetically modified Bt maize is cultivated, Bt protein does indeed enter the soil via root exudates, harvest residues and pollen deposits. But even on fields on which Bt maize had been cultivated for three years in succession, no Bt protein was detected in the soil before the next crop was sown. Fields with different soil characteristics were studied, but no accumulation of the Bt protein was found on any of them. These investigations were carried out with different types of Bt maize containing the Bt proteins most commonly used in GM plants today: Cry1Ab, Cry1A.105, Cry2Ab and Cry3Bb1.
Even a long-term trial commissioned by the Bavarian government, in which Bt maize was grown on the same field for eight years in succession, was unable to detect any accumulation of Bt protein in the soil.
Many soil organisms are sensitive to various environmental factors. For instance, in trials with nematodes, dramatic differences were found in the numbers of organisms and in the species composition depending on soil quality and weather factors. However, when Bt maize was grown instead of conventional maize, neither the bacterial and nematode communities or earthworms showed any reaction. The numbers of organisms in the soil and the species composition remained constant. Some of these trials were conducted over a period of three years on the same field. Even earthworms fed continuously on a diet of leaf remains from MON810 maize did not come to any harm.
Pit traps: Between 2008 and 2010, field research was carried out to see what impact GM maize containing two types of Bt protein and a herbicide resistance had on non-target organisms, including beetles. No combination effects were found.
BÖLW study claim: Potential combination effects of various Bt proteins are not taken into account during risk assessments within the EU approval procedure. There is a danger that effects could overlap and have a greater cumulative impact.
Current state of research and knowledge: The results of research projects carried out so far in this area provide no indication that different Bt proteins have a cumulative effect. In a three-year joint project, researchers in Germany investigated a type of Bt maize that contains the Bt proteins Cry2Ab, Cry3Bb1 and Cry1A.105, that is composed of the Cry1Ac, Cry1Ab, Cry1F. No harmful effects were detected on arthropods or soil organisms like nematodes, earthworms and bacteria in the field, even with this variety of Bt maize. The speculation that the effects of the Bt proteins could overlap or that their combined impact could be more powerful was not confirmed in any of the research projects.
Butterflies and moths: Measuring the intake of maize pollen under field conditions
BÖLW study claim: The risk assessment for European butterflies whose caterpillars are known to be sensitive to the Bt toxin is based largely on computer models and not on empirical research.
**Current state of research and knowledge: As well as a number of international studies, practical experiments have also been conducted in Germany under field conditions with various Bt maize varieties. A key finding was that only small amounts of pollen are found on the butterflies’ food plants even in the immediate vicinity of a Bt maize field. The pollen quantities that led to higher mortality rates in caterpillars in the laboratory were not found on any food plant in the field. In addition, the projects showed that only some of the caterpillars are found near maize fields, so they are not at risk. Overall, one can say as a result of the empirical results that the risk to butterflies is negligible.
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Bt maize: No risk for butterflies and moths
Result of a three-year research project at RWTH Aachen University.
Bt maize: Impact on soil quality?
Interview with Prof. Christoph Tebbe, vTI Braunschweig (July 2010)
Bt maize and ecosystem
When scientists are investigating the possible effects of Bt maize on the maize ecosystem, how can they distinguish between natural fluctuations and a possible effect caused by the genetic modification? GMO Safety discussed this with Stefan Rauschen from RWTH Aachen University.
- Deutscher Bundestag / Parlamentsfernsehen; Sitzung des Petitionsausschusses vom 26.09.2011; Petition gegen des Einsatz der Agro-Gentechnik
- BÖLW, Bund Ökologische Lebensmittelwirtschaft; Petition Gentechnik
- BÖLW-Studie, Risiken mit amtlichem Siegel: Mängel bei der Zulassung gentechnisch veränderter Pflanzen
- WGG, Wissenschaftlerkreis Grüne Gentechnik e.V.
- WGG: Wahlfreiheit bedeutet: Kein Anbauverbot für gentechnisch veränderte Pflanzen