THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and Colleagues
Assessment of Stacked Bt Soybean Overlooks Potential Health Risks
In June 2012, the European Food Safety Authority (EFSA) approved, for the first time, genetically engineered stacked soybean MON87701 × MON89788, produced by Monsanto and sold under the brand name Intacta, for import and use in food and feed in the EU. The soybeans combine the expression of an insecticidal Bt toxin, Cry1Ac, present in the parental event MON87701, with herbicide resistance to glyphosate from parental event MON89788.
A recent review, published in the Journal Environmental Sciences Europe, examines the associated health risks and the risk assessment undertaken by EFSA based on the data from Monsanto, which carried out field trials in the US and Argentina. The review found serious gaps in the assessment of Intacta, which need further examination: thepotential combinatorial effects between plant components and other impact factors that might enhance toxicity; the immunogenic properties of Bt toxins; the lack of reliable protocols for measuring the Bt concentration in the plants; and the impacts of glyphosate residues and their interaction with Bt toxins.
The researchers recommend a major review of the concept of comparative risk assessment. Among other things, they call for detailed investigations into: the toxicity of Bt toxins; combinatorial effects taking into account long-term effects and the residues from spraying with complementary herbicides; and the impacts on immune and hormonal systems. They stress that stacked events displaying a high degree of complexity due to possible interactions should not undergo a lower level of risk assessment than the parental plants. Since further soybean varieties expressing Bt toxins are already in the pipeline, these issues require urgent attention.
With best wishes,
Third World Network
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10400 Penang
Malaysia
Email: twn@twnetwork.org
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POSSIBLE HEALTH IMPACTS OF BT TOXINS AND RESIDUES FROM SPRAYING WITH COMPLEMENTARY HERBICIDES IN GENETICALLY ENGINEERED SOYBEANS AND RISK ASSESSMENT AS PERFORMED BY THE EUROPEAN FOOD SAFETY AUTHORITY EFSA
Then, C., & Bauer-Panskus, A.
Environmental Sciences Europe, 29(1), 1.
doi:10.1186/s12302-016-0099-0
https://link.springer.com/article/10.1186/s12302-016-0099-0
Abstract
Background
MON89788 was the first genetically engineered soybean worldwide to express a Bt toxin. Under the brand name Intacta, Monsanto subsequently engineered a stacked trait soybean using MON89788 and MON87701—this stacked soybean expresses an insecticidal toxin and is, in addition, tolerant to glyphosate. After undergoing risk assessment by the European Food Safety Authority (EFSA), the stacked event was authorised for import into the EU in June 2012, including for use in food and feed. This review discusses the health risks associated with Bt toxins present in these genetically engineered plants and the residues left from spraying with the complementary herbicide.
Results
We have compared the opinion published by EFSA [1] with findings from other publications in the scientific literature. It is evident that there are several issues that EFSA did not consider in detail and which will need further assessment: (1) There are potential combinatorial effects between plant components and other impact factors that might enhance toxicity. (2) It is known that Bt toxins have immunogenic properties; since soybeans naturally contain many allergens, these immunogenic properties raise specific questions. (3) Fully evaluated and reliable protocols for measuring the Bt concentration in the plants are needed, in addition to a comprehensive set of data on gene expression under varying environmental conditions. (4) Specific attention should be paid to the herbicide residues and their interaction with Bt toxins.
Conclusions
The case of the Intacta soybeans highlights several regulatory problems with Bt soybean plants in the EU. Moreover, many of the issues raised also concern other genetically engineered plants that express insecticidal proteins, or are engineered to be resistant to herbicides, or have those two types of traits combined in stacked events. It remains a matter of debate whether the standards currently applied by the risk assessor, EFSA, and the risk manager, the EU Commission, meet the standards for risk analysis defined in EU regulations such as 1829/2003 and Directive 2001/18. While this publication cannot provide a final conclusion, it allows the development of some robust hypotheses that should be investigated further before such plants can be considered to be safe for health and the environment. In general, the concept of comparative risk assessment needs some major revision. Priority should be given to developing more targeted approaches. As shown in the case of Intacta, these approaches should include: (i) systematic investigation of interactions between the plant genome and environmental stressors as well as their impact on gene expression and plant composition; (ii) detailed investigations of the toxicity of Bt toxins; (iii) assessment of combinatorial effects taking into account long-term effects and the residues from spraying with complementary herbicides; (iv) investigation into the impact on the immune and hormonal systems and (v) investigation of the impact on the intestinal microbiome after consumption. Further and in general, stacked events displaying a high degree of complexity due to possible interactions should not undergo a lower level of risk assessment than the parental plants.