ngin - Norfolk Genetic Information Network

21 January 2003


This is a briefing on the GM food aid issue by Tewolde Egziabher who heads Ethiopia's environment protection agency. At the end of last year's Earth Summit in Johannesburg Tewolde Egziabher was described in one British newspaper as the "one genuine hero" of the summit. An article in The Independent during the course of the summit noted the critical role he played in representing not just the interests of Ethiopia but those of the Third World as a whole:

"American plans to force genetically modified crops and food on to Third World countries were unexpectedly frustrated at the Earth Summit last night.

After an impassioned plea from Ethiopia, ministers rejected clauses in the summit's plan of action which would have given the World Trade Organisation (WTO) powers over international treaties on the environment.

...Originally, the only resistance to the proposals came from Norway and Switzerland but after the Ethiopian delegation made its intervention the rest of the Third World swung against it, followed by the European Union which had originally been pushed into adopting it by EC officials. The US was left isolated.

"I have never seen so many environmental ministers hugging each other as when the proposal went down,'' said one British negotiator early this morning. "


Facts to Consider when Receiving Genetically Engineered Food Aid

Tewolde Berhan Gebre Egziabher

1.  Introduction

Drought has hit Southern Africa, and the United States of America has sent to the affected countries genetically engineered (GE) maize as food aid.

Zambia has totally refused to accept it for fear of negative impacts on health and contamination of its agricultural production and environment.

Other Southern African countries (e.g Zimbabwe and Malawi) have decided to accept the risk to human health, but not to agriculture and the environment. Therefore, they have insisted that the GE maize be ground into flour before being brought in.

Ethiopia and Eritrea have also been hit by drought and they are likely to be offered  GE maize. To the extent that we can determine, what are the risks and the possible responses?

2.  What Are the Causes of the Risks Posed by Genetic Engineering?

Genes determine traits, e.g. eye colour, hair texture, height in humans. Cells contain many silent genes, or genes that are not expressed. Normally, genes from parents become mixed in the offspring only within the same species. Less frequently, genes from closely related species may also mix.

But genes from unrelated species do not mix in nature. However, through genetic engineering, a gene or genes from a totally unrelated species can be introduced into any species, e.g. from the bacterium, Bacillus thuringensis, to maize, and from humans to bacteria.

In genetic engineering, the gene to be transferred is isolated. If transferred on its own, it fails to be expressed, i.e. it becomes a silent gene. Therefore, a part of a gene known to force expression, called a promoter, is attached to it. But the promoter causes the expression of other silent genes as well. It may even enhance the expression of functional genes. Therefore, a part of a gene known to stop expression, the terminator, is also attached to it. This combination is called an expression cassette.

Nevertheless, genes are known to have impact on the functions of other expressed genes even when not physically attached to them.1 Therefore, it is possible that either or both the promoter and the terminator may  affect or be affected by the actions of other expressed or non-expressed genes and thus modify the genetically engineered organism in ways that cannot be predicted.2  A marker gene, usually one that makes the GE organism resistant to an antibiotic, is also attached. The expression of resistance to antibiotics can be transferred to the bacteria in humans and animals, thus making the antibiotic useless as a medicine. The expression cassette can be represented as follows.
Two or more expression cassettes may be linked end to end. The linked up expression cassettes constitute a construct.

The construct is then sometimes directly pushed into the cells that are being engineered. Usually, however, it is introduced through a vector. A vector is a disease causing bacterium, virus or plasmid that has been disabled. This disabling is achieved by removing a portion of the vector.

The construct is then introduced into the disabled vector. The vector thus smuggles the construct into the cells of the receiving species.

Inside the GE species, the portion removed from the vector to disable it may recombine with it; or a similar portion taken from another microorganism may attach to it. This would turn the disabled vector into a disease agent, possibly new and more dangerous.

The construct may also be attached to a naturally occurring small gene called a transposon which then acts as the vector to smuggle in the construct. These transposons keep jumping from species to species. The gene(s) attatched to transposons may, therefore, easily contaminate unintended species.

Whether introduced physically or through a vector, the genes in the construct become part of the cell and determine traits.

The antibiotic resistance trait is used to select the cells that have had the construct introduced into them. When the mixture of cells is treated with the antibiotic, those cells which are without the antibiotic resistance gene die, and it is the genetically engineered cells that survive.

The mixing of genes from different species can also be achieved through cell fusion. Cells from different species are brought together and, under certain conditions, they fuse into a new one containing the genes of both species.

The mixing of genes inside the GE cells is random. The construct can attach itself to any other gene in the receiving organism. The genes may also rearrange and not necessarily stay in the same condition as they were when they were put into the gene construct. The expression of traits thus becomes unpredictable, unstable and likely to pose risk.2  The thus genetically engineered cells are then cultured and they develop into whole microorganisms, plants or animals. We call these living things resulting from genetic engineering 'transgenic organisms', and the transferred gene is called a 'transgene'.

Genes from the genetically engineered individual, whether dead or alive, are ingested by bacteria. These bacteria can transfer their genes, including those ingested from GE organisms, to other bacteria, plants or animals.3,4

By way of a summary, it can thus be pointed out that the risks posed by genetic engineering arise from the following causes:

a) The new combination of genes does not occur in nature, and therefore, the net result of genetic engineering cannot be fully predicted, nor even fully understood afterwards.

b) The insertion of the gene construct in the cell and its position among the genes of the cell cannot be predicted. The effect of the introduced genes has thus to show itself before it can be known.

c) The effects of the promoter, terminator and vector are not predictable, and there may be many unexpected consequences.

d) The transferred genes, promoters, terminators, or even vectors may move into other species and cause unexpected results through crossing or through the agency of bacteria.

e) Some of the new biochemicals produced in the GE organism may become toxic, allergenic, carcinogenic, terratogenic or dangerous to humans and/or animals in other ways.

f) The GE species or any other species which has acquired the transgene(s) may become a very bad weed in crop fields or in natural ecosystems.

3.  What Should the Basis of Risk Assessment Be?

The United States of America was the country that pioneered most aspects of genetic engineering, especially in crops. The regulatory authorities adopted a strategy that has now come to be called Substantial Equivalence.  This strategy starts from the premise that the introduction of 1 or 2 new genes into an organism of tens of thousands of genes  is a small and thus an insignificant modification and that, therefore, the impact must also be insignificant. This leads to the view that a GE organism should be assumed to be as safe as the non-genetically engineered parental organism. If an unlikely change has occurred, it will be noticed during the use of the GE organism, and taking action as the problem arises will thus suffice.5

The opposite strategy, called the Precautionary Principle, has been adopted in the Cartagena Protocol on Biosafety (Articles 10.6 and 11.8) and in the African Model Law on Safety in Biotechnology (Article 6.7 and 6.8). The Precautionary Principle requires that, in cases where there is no certainty of the absence of risk, the necessary care shall be taken to prevent harm.

When genetically engineered species were allowed to be used in the United States of America, the Substantial Equivalence strategy was used to declare them safe. But virtually all the rest of the world, including Europe, accepts the strategy of the Precautionary Principle and rejects the strategy of Substantial Equivalence. That is why Europe does not recognize the certification of safety issued by the United States of America. The Difference between Europe and the United States of America with regards to genetically engineered products arises from this basic difference in principle, and not from competition for the market.

4.  What are the Risks to Human Health Posed by Genetically Engineered Maize?

A gene taken from the bacterium, Bacillus thuringensis, made into a construct with a promoter, a terminator and a vector, has been introduced into Bt maize. A gene that gives the maize plant  resistance to a particular herbicide, glyphosate, named Roundup Ready by Monsanto, has been introduced into HT maize, again together with a promoter, a terminator and a vector.

The GE maize that may come to Africa is likely to be Bt or HT. But we can not be certain. Given the uncertainly of which transgenic maize variety or varieties may be given to Ethiopia as aid food, what is the herbicide to which the GE maize has resistance, if any, and what are the promoters, terminators and vectors; it is not possible to guess with any accuracy what the health hazards would be. Even if and when these unknown variables are identified, there would still be much uncertainty because of the impossibility of predicting how all these introduced genes and the parental genes interact.1,2

We can however, be sure that we need not fear toxicity since the maize varieties are presumably those being used as human food in the United States of America, and any such toxicity would already have been detected. However, there are also genetically engineered maize varieties in the United States meant only for animal feed, e.g. the Starlink maize. In September 2000, food made from maize in the United States was found contaminated with Starlink.6

It was destroyed. But, can we be certain that the maize that may be sent to us is free from contamination by Starlink or any other variety not cleared for human food?

Because of the use of Substantial Equivalence in certifying GE crops safe for human consumption, such possibly long term effects as build-up of allergenicity, carcinogeny, terratogeny etc. have been ignored. However small, therefore, there are risks that giving GE food to starving people could be dangerous. A study showing the prevalence of unexplained alimentary canal complications between Sweden and the United States has shown that in Sweden, where GE food is not allowed, there has been no increase but that in the United States, where GE food is eaten, there has been a several fold increase.7

In the United States, GE maize constitutes only a small portion of the diet. If GE maize were given to starving people, it would constitute the whole of their diet. It is likely, therefore,  that such complications would be more devastating among victims of famine.8 When eaten in large quantities, it is possible that human reproduction will be reduced as has been reproduction among pigs.9

5.  What Are the Risks to Ethiopian Agriculture

Maize is wind pollinated. Therefore, a GE maize will easily have its pollen reaching non-GE maize. Reports of such contamination are many.10

If, in the future, it is found  that any of the genes in the GE maize cause problems, it would be impossible to bring back the original non-contaminated maize.

Maize is the most important food crop in most of Subsaharan Africa. Such a contamination would, therefore, be a major set-back to Africa.

Africa would then be barred from exporting maize to Europe and to developing countries in other continents. The current size of Zambian maize export to Europe is worth US $ 400,000,000.

Domestic animals refuse to eat the stems and leaves of Bt maize11, and pigs, if made to eat Bt maize, have their reproductive capacity greatly reduced.9

Therefore, even if hunger forces domestic animals to eat Bt maize residues, they will not be able to reproduce effectively. Domestic animals would thus either have their feed reduced, or their reproduction reduced. African agriculture, and particularly Ethiopian and Eritrean agriculture, is based on mixed animal rearing and crop production. The introduction of Bt maize would thus disrupt it seriously

The introduction of GE maize will not increase yields.11  Various studies have shown that GE crops usually yield lower than their respective non-GE equivalents.12,13,14

6.  What Are the Risks to the African Environment?

Maize has no closely related species in Africa. Therefore, the risk of the transgenes going into wild species through cross pollination is insignificant.

Neither is it likely that maize in Africa will become a weed in the natural vegetation.

However, Bt maize is known to kill butterflies15 and thus presumably also moths. Butterflies and moths are important pollinators of crops (e.g. pulses) and wild plants. The spread of Bt maize would thus be not only disruptive of the  environment, but it would also be economically damaging.

7.  What Are the Possible Problems Related to Patenting

The genes or parts of genes (promoters, terminaters, whole genes) and vectors introduced during genetic engineering as constructs are all patented. When they contaminate the non-genetically engineered varieties, therefore, they turn them into patented varieties. Article 34 of the Agreement on Trade-related Aspects of Intellectual Property Rights of the World Trade Organization considers anybody found with a patented object in his possession to be an infringer of the patent, a criminal. Therefore, our peasant farmers would not only lose their own non-genetically modified varieties of maize, but they would also become patent infringers and thus also criminals. A farmer from Canada, who maintains that his field of rapeseed was contaminated by cross pollination from  another field of GE rapeseed, was found guilty and ordered to pay damages.16

Ethiopia is not a member of the World Trade Organization and its peasant farmers could not be turned criminal just because they have their own varieties contaminated. But they would become criminal when it joins the World Trade Organization. They would be forced to pay fines and, in the future, be forced to pay royalties every maize planting season. Most countries in Africa are members of the World Trade Organization; and their farmers would turn criminal immediately.

8.  What Should the Response of an Affected Country Be?

I can give my suggestions. But they may pre-empt discussion. Since the problem affects all of us, it is best if we join all our views in idea generation. I will, therefore refrain from suggestions in the hope that you will produce them.


1. Samuel, E, 2001, "Listening in to conversations between molecules can
be a nightmare", New Scientist, vol. 171, Issue 2299, p. 16

2. Ho, M.W, 1999. Genetic Engineering: Dream or Nightmare? The Brave New World of Bad Science and Big Business. Gateway, Gill & Macmillan: Dublin.

3. Levy, S. B. and R. B. Miller (ed.), 1989, Gene Transfer in the Environment.    McGraw-Hill: New York,  give a detailed review of horizontal gene transfer. A more recent but not detailed treatment can be found in: National Research Council, 2002, Environmental Effects of Transgenic Plants. National Academy Press: Washington D.C., p. 66-67.

4. National Research Council, 2002, Op.cit, p. 66-67 refers to this problem briefly. Ho, M.W, 2001, Horizontal Gene Transfer - the Hidden Hazards of Genetic Engineering. Third World Network: Penang,  gives more detail and on p. 12-14 argues that transgenic DNA may be more likely to be horizontally transferred than ordinary DNA.

5. Millstone, E, E. Brunner and S. Mayer, 1999, "Beyond substantial equivalence", Nature vol. 401, p. 525-526.

6. Soil Association, 2002, Seeds of Doubt: North American farmers' experiences of GM crops. Soil Association: Bristol, U.K. p 25-34.

7. Ho, M.W, 2001, US Foodborne Illnesses Up Two to Ten Fold, ISIS Report, 3 November 2001.

8. On 13 September 2002, Dr. Charles Benbrook, former Executive Director of the  US Board of Agriculture of the US National Academy of Sciences, emphasized this fact in an address to a Zambian delegation visiting the US on a fact finding mission on GE food.

9. Soil Association, 2002, Op.cit., P. 36.

10. Ibid, p. 25-34.

11. Ibid, p. 12. More detailed information is found in Benbrook, C. M., 2001, When Does It Pay to Plant Bt Corn? Farm-Level Economic Impacts of Bt Corn, 1996-2001. Benbrook Consulting Services, Idaho. This document can be retrieved from:

12. Soil Association, 2002, Op.cit., p.11.

13. Ibid, p.11.

14. Ibid, p.12. A more detailed treatment can be found in Fulton, M. and L. Keyowski, 1999, "The producer benefits of herbicide-resistant Canola", AgBioForum, vol. 2, no. 2, p. 85-93.

15. National Research Council, Op.cit, p. 71-76, gives detail on the effect of Bt maize on monarch butterflies. The original report  was made by Losey, J.E, L.S. Rayor and    M. E. Carter, 1999, "Transgenic pollen harms monarch butterflies", Nature, no. 399, p. 214.

16. Dr. Tewolde B. G. Egziabher has personally met Mr. Schmeiser several times and they have discussed his case, which is now extensively covered by the media in Canada, e.g. see Kennedy, J., 2002, "Are we  being genetically modified? Schmeiser/Monsanto case shows extent of GM foods threat", Canadian Centre for Policy Alternatives Monitor. This can be viewed at the website articles/article322.html. Litigation around failures in GE crops is becoming common, e.g. that of Smirall and Smirall versus the Jacob Hartz Seed Company Inc. of Mississippi, USA, concerning failure of Roundup Ready tolerant soya bean. The case can be viewed at.

17. Dr. Charless Benbrook (see note no. 8) has clearly pointed out this fact.

18. The Zambian newspaper, the Times of Zambia, of 13 Nov. 2002 reported that the European Commission gave Zambia 15,000,000 pounds to buy non-GE food for its drought victims.

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