Select Committee on European Communities Second Report



73.  The risks to human health of GM crops when eaten are considered in paragraphs 109 to 116. It has been argued that some modifications may, while in the field, pose risks to humans or unintended harm to other animals. This may be due, for example, to an increase in the allergenicity of pollen. These issues are considered and tested during trials and assessed in the risk assessment. Our comments relating to risk assessment must be considered as applying to this aspect of GM crops as much as to environmental issues.


74.  The risk to the environment of GMOs is much more difficult to estimate than the effect on human health. Many modifications, such as slower ripening, are likely to have no effect at all, good or bad. The assessment of risk is also complex, for the intensification of agriculture has increased food supply and quality, but at a cost to the environment through chemical weed and pest control, the use of fertilisers, a reduction in the number of varieties of many crop plants in cultivation (Professor Williamson, Q 490) and a reduction in wildlife habitats. The risks of a GM crop must not thus be considered in isolation, but compared to the risks of current agricultural practice and an assessment of best practice. The risks posed by GMOs are, however, intangible and yet to be demonstrated (Professor Burke, former chairman of the advisory committee on novel foods and processes (ACNFP) and Professor Beringer, chairman of the advisory committee on releases into the environment (ACRE), Q 36). Many of the claims which have to date reached the headlines have been misleading[114]. Harm to the environment or otherwise by GM crops has yet to be demonstrated experimentally, but many of our witnesses believed that the following issues need to be addressed.



75.  It is certain that gene transfer between micro-organisms takes place, but this has to be set in context (Professor James and Dr Chesson, QQ 641-3). It only causes a problem when the transfer is to a pathogenic organism or if the resultant organism is a pathogen. The transfer of genes from micro to higher organisms (such as plants) occurs only with very few bacteria such as Agrobacterium, used in one type of modification process[115]. Transfer from plants to bacteria is extremely improbable[116]. The possibility has however led to particular concerns about furthering the spread of antibiotic resistance through the use of antibiotic-resistant marker genes (Gene Watch, p 335). Recently an ampicillin tolerance gene was included within a transgenic maize. It was a bacterial gene, complete with a bacterial promoter[117]. ACNFP was concerned at the remote but finite possibility that the gene could be transferred to bacteria within the rumen of a cow which ate the maize as feed and concluded that it therefore constituted a hazard (Professor Burke, Q 35, also Professor Bainbridge QQ 693-4)[118]. An eventual decision allowing the use of this maize within the European Community was based on the presumption that the gene could be transferred, and weighed the consequences against the existing prevalence of ampicillin resistance within bacteria. Antibiotic resistant marker genes are not now used in new products (Dr Chesson, Q 669). We consider that ACNFP was correct to proceed with extreme caution where the possibility of furthering antibiotic resistance was present[119]. In view of the fact that alternatives are now available, antibiotic-resistant marker genes should be phased out as swiftly as possible.


76.  There is evidence to show that DNA from any food can survive in a human's gut and even be absorbed by gut cells (Professor James and Dr Chesson, Q 639). The incorporation of such DNA into the genetic material of the cell must however be an extremely rare event (Q 640)[120]. We discuss this issue in paragraph 109).


77.  Gene transfer is dependent on sexual compatibility and not all plants are compatible with each other, hence the limitations of conventional breeding. In the agricultural environment, genes may be transferred to similar crop plants in adjacent fields[121]. This is a hazard already faced by farmers growing similar crops at close quarters. Under normal circumstances, this would only be a hazard if the affected farmer retained seed for replanting in later years[122], but with those plants where the seed is the crop this would be a problem within the same year as seed on adjacent crops might inherit the transgenes and so alter the crop's characteristics. As modifications become more varied this may have serious implications for what crops can be grown next to each other and for the retention of seed for replanting (see also paragraphs 105-106). Where plant-produced pharmaceuticals are concerned, we recommend either that these are grown indoors or that out-crossing should be made biologically impossible, by, for example, ensuring male sterility.

78.  The Soil Association saw the introduction of genetically modified plants into United Kingdom agriculture as the "most serious threat ever to the objectives and progress of the organic farming movement in developing and introducing viable systems-based approaches to agriculture" (p 390). The European Commission has proposed that products containing or derived from GMOs should not be allowed to be used for foods sold as organic. Professor Williamson however considered the organic movement's rejection of genetic modification to be unfortunate, as GM was compatible with sustainable lower input farming (Q 499). This view was reinforced by our visit to the John Innes Centre, when staff suggested and demonstrated that current GM crops were designed for more sustainable agriculture with less reliance on chemicals. To take the example of pest resistant crops, either a pesticide can be engineered into the crops (as with those using Bt) or the crop can be modified to attract insects which prey on the pest. The latter method seems compatible with the principles of organic farming. Risk management procedures need to be employed to minimise transfer of the genes into adjacent crops, particularly those owned by other farmers. This is of particular importance where organic crops are grown, as drift of the transgenes into the seeds might result in harm to the property of the organic farmer. It should be a responsibility of farmers to prevent out-crossing (see paragraphs 105-107). We consider that GM technology may offer much to organic systems, for example through reduced inputs.


79.  If there are weeds which are sexually compatible with a herbicide tolerant crop (such as weed beet with sugar beet), the out-crossing of transgenes may cause significant harm to the agricultural environment (SNCAs, p 320), but only if other methods of control, such as selective herbicides, are not available (Zeneca, Q 89). Transfer of such genes into wild relatives in the natural environment could result in irreversible effects on natural vegetation (Dr von Schomberg, pp 401-2). There will however not generally be selection pressure to retain the transgene and it should in time disappear. The transfer of herbicide resistance outside agriculture is unimportant in areas where herbicides are not generally used (for example field margins or woodland), but could cause control problems in areas dependent on chemical control, such as road-side verges, railway tracks or runways.

80.  A herbicide-tolerant crop may also establish itself as a weed and cause harm to the ecology and its processes within any ecosystem in which it stabilises (Royal Society for the Protection of Birds (RSPB), pp 384-5). Professor Williamson suggested that this cannot be predicted as there is some uncertainty as to what makes plants weedy. He suggested that the characteristics that would be expected to indicate invasiveness could not be expressed quantitatively (Q 505). In the agricultural environment, should a herbicide tolerant crop survive into the next growing season (described as a "volunteer"), it will pose weed problems for the new crop and may, if compatible, breed with it. This would increase the rapidity of multiple tolerances developing.


81.  If varieties of the same crop are modified to express tolerance to a range of herbicides, gene-stacking may eventually occur (Iceland, p 64). This is where a plant develops resistance to a number of systemic herbicides commonly used in agriculture and effectively becomes less controllable. Zeneca noted that this is a longstanding agricultural issue (QQ 89-90) which requires that new agricultural chemicals be developed every decade[123].


82.  If a crop plant is modified so that it is able to be grown in new environments (geographical locations, altitudes, soil types, conditions of excess water or drought, or even different seasonal cropping) it may become a weed or pose risks to the environment into which it is newly introduced (Professor Beringer, Q 25; Professor Williamson, Q 505). Such a risk would need to be set against the benefit of the crop's introduction. Land on which wildlife depends, previously not used for cropping, may be brought under cultivation.


83.  The development of pest resistance has so far focused on genes which produce the toxins derived from the bacterium Bacillus thuringiensis (Bt)[124]. These toxins are effective against a range of insects, particularly certain lepidoptera, but are harmless to plants and to humans[125]. They are used in a wide range of pesticides and the bacterium itself is used for pest control in organic systems. Pesticides are normally applied to crops at specific times during their growth and normally dissipate and are rapidly degraded in the soil. Conversely, plants which express pesticides are likely to do so uniformly, throughout the life of the plant, which may result in a greater likelihood of insects developing resistance to the effects of the toxin (Greenpeace Q116). GM crops may be much more effective at killing target insects and other susceptible insects and so deprive of food higher organisms which prey on them, such as birds (RSPB, p 386). On the other hand, the impact of pest resistant plants may be beneficial due to their selectivity, because the pest resistance only affects insects which attack the plant, as opposed to a spray which affects all susceptible insects in the field. Whether the net effect will be positive or negative has yet to be resolved.


84.  Changes in farming practice during the past 30 years have already had a significant impact on wildlife as, throughout Europe, it is particularly dependent on farmland (RSPB, pp 386-7). Farmland constitutes 70 per cent. of the United Kingdom's land area, much more than in the United States[126]. In addition, the use of agricultural chemicals per acre in Europe is much higher than in the United States. Due to both of these factors, sensitivity to the possible impact of genetically modified organisms on the environment may be much more significant within Europe than in the United States.


85.  There is concern, shared by farmers, witnesses and ourselves, that the powers of a few agro-chemical/seed companies are already very great, and will become even greater, over the process of producing (developing and growing) genetically modified crops. United States soybean producers told us of their anxiety that in the future they would be growing specialised, value-added GM crops, the profit from whose added value would accrue predominantly to the companies rather than to themselves. Additionally, agricultural biodiversity (the number of varieties of a particular crop in production) may also be further reduced by consolidation in the industry when it is already an issue of concern[127]. In this respect, the Seed Bank at Kew acquires added significance[128]. It is highly desirable that there should be competition between a sufficient number of companies on a world-wide basis. The degree of consolidation[129] is already much greater than that which obtains in the pharmaceutical sector and we consider that it should not progress any further. It is however a competition issue and should be dealt with by competition law. The multi-national aspect of the agrochemical/seed sector must not override regulation. Should agrochemical companies pursue research prohibited in Europe in countries which lack as stringent a regulatory system, we would deplore such actions.


86.  GM crops introduced commercially in the United States have resulted in a change to farming practice in that farmers no longer have the right, or sometimes the ability, to retain seed for replanting the following year. This is either because the seed company insists on licensing the right to plant[130] or because the plant is male sterile, and so produces no seed. Where the crop is male sterile, this has the environmental advantage that out-crossing and back-crossing are impossible (NFU, Q 290). The American Soybean Association, in contrast to the NFU (Q 291), does not consider this to be a problem as they value the guarantee that all their seed is first quality and free from disease. They have chosen to purchase the entirety of their GM seed rather than follow their tradition of keeping up to two thirds of seed for replanting the following year. As value added products (such as altered oil property soya) are introduced, it will be important for the farmer to be certain of seed quality and origin to ensure that the desired modification is in fact present in the crop. This change-over from retention to non-retention of seed is not as dramatic as it seems, for many of today's agricultural crops are hybrids which lose their vigour (and hence their yield value) after the first use. In relation to the developed world, so long as the farmer's economic prosperity is not unduly affected, we do not consider either the licensing of the right to plant or the sale of seeds which will produce sterile crops to be a problematic development. Both of these approaches should assist product traceability. In the developing world, however, many and probably most farmers would view the prospect of having to buy seeds each year with grave concern.


87.  We recognise that there could be significant potential risks to the environment associated with the use of genetically modified organisms but are convinced that the benefits could be substantial in terms of yield, quality and new products. We agree with Professor Williamson that this technology is "certainly desirable" (Q 487), but is only likely to succeed if it gains widespread public acceptance and trust in its safety. The process of assessing risk is therefore of crucial importance to the future of the technology.

88.  Current risk assessment procedures for both trial and commercial releases assess solely the risks of allowing the release to proceed and do not consider any benefits. Many witnesses recommended that risk assessment should be replaced by "environmental impact analysis", which would take environmental benefits into account as well as risk (Novartis, pp 372-3). (If it is possible to identify environmental risk, then it must be possible to identify environmental and other benefits.) "It would be useful, therefore, if both regulators and consumers were able to balance potential risk against possible benefit" argued Dr Gliddon (pp 340-1). We consider that environmental risks and benefits should be assessed at the same time.

114  Two notable causes célèbres are those of lacewings which might eat the European cornborer, poisoned by Bt maize (a secondary effect) and the potato to which an immune system affecting lectin had been added. Swiss research has suggested that lacewings, if fed on the larva of cornborers, (which Bt maize is designed to kill) could also be killed, with potential effects on the entire ecosystem. ACRE was unhappy with the research, as, in practice, the lacewing would never gain access to the cornborer as the cornborer is inside the maize (see Novartis, pp 377-8). Scots research demonstrated that a lectin known to affect the immune system retained this characteristic when transferred into a potato, or mixed with potato. It was not and is not suggested that this lectin would ever be used in a food, and, were it to be, it is more than unlikely that ACNFP would approve it (see Professor James, QQ 637, 644). Back
115  See paragraph There are two main methods for the transfer of genes into plants. The first involves the use of a soil bacterium, Agrobacterium tumifaciens, which infects certain plants. It injects a piece of DNA into the plant cell to attempt to take over the cell's protein manufacturing machinery and so produce a sugar on which the bacterium can feed. This piece of DNA is incorporated into the genome of the infected cell. Scientists use this piece of DNA by effectively hijacking it. Having removed some of the unneeded genes, they are able to insert desired genes into the vacated space. Using Agrobacterium it is possible to modify many dicotyledonous (broad leaf) plants such as potato, rape, tobacco and tomato and the technique has been adapted to work on maize, wheat and rice. The second method involves the use of "biolistics" (the "gene gun") where the desired gene package is coated around finely divided gold particles and literally fired into plant cells. A small percentage of the plant cells is transformed in each case. In either method, one of the genes inserted into the plant will produce a protein that confers tolerance to a chemical that would normally kill the cell, a herbicide for example. When the chemical is administered, only those cells which have been effectively transformed and satisfactorily express the new gene product are not killed and a complete plant may be regenerated from these. (This gene is termed a "marker gene" because it is used to identify the presence of the transgene.) The laboratory modification is only carried out on a suitable sub-set of varieties of the crop. These varieties are then crossed (and back-crossed) using traditional breeding technology in order to put the desired genetic material into choice varieties for agricultural production. above. Back
116  Genes in higher organisms tend to include regions of DNA that do not code for protein (termed introns). Bacteria are not able to translate these genes, hence expression is almost impossible. The promoter sequences in higher organisms are also significantly different from those in prokaryote organisms. Even where transgenes do not include introns, the probability of transfer of genes from higher organisms into bacteria remains extremely improbable. Back
117  Novartis, pp 375-6 and Annual Report of the ACNFP, 1996, Appendix IV, pp 55-62. Back
118  In 1994 ACNFP reported "on the use of antibiotic resistance markers in genetically modified food organisms". They concluded that antibiotic resistance markers in foods should be evaluated on a case by case basis and that the evaluation should include assessment of the clinical use of the antibiotic, the likelihood of transfer (and expression) of the gene into gut micro-organisms and the toxicity of the gene product. Back
119  The events that led ACNFP to advise the United Kingdom competent authority to oppose the marketing of the maize are fully documented in the annual reports of the Committee for 1996 and 1997. ACNFP is however also correct in accepting that once the Commission, advised by its scientific committees, has decided that this gene and its product does not pose a risk (as the resistance is already widespread in the environment) it can no longer justify objections to products containing this or similar genes. See also the recent report of the Science and Technology Committee, 7th Report (1997-98): Resistance to antibiotics and other antimicrobial agents (HL 81-I). Back
120  See also New Scientist, 31 October 1998 (No 2158), p 44. Back
121  Whether genes can be transferred depends on how closely related the parents need to be for a successful match and also on the pollen from the GM variety physically reaching the other plant. The distance over which pollen can travel is dependent on the crop and prevailing environmental conditions such as temperature, wind and insect populations. It is impossible to provide general figures for pollen viability, but MAFF recommends the following isolation distances for producing 99 per cent. pure seed: wheat, barley or oats, 2m or physical barrier; oilseed rape, 200-500m; sugar beet, 1,000m. A trial of one oilseed rape at the John Innes Centre found 0.0038 per cent. pollution at 400m, but this is only one variety in one particular circumstance. Back
122  Currently, for most crops, approximately one third of seed is retained. Back
123  Mr Rooker announced to us that herbicides will require a separate approval to be used on GM crops (Q 603). Back
124  Products containing this organism constitute 80 - 90 per cent. of the microbial pesticides which are purchased and used. It was first registered in the United States in 1961. Back
125  POST, op. cit., p 12. Back
126  The Ministers were keen to note that not only did farming only cover 10 per cent. of the United States, but that "natural" countryside in the United States (for example the national parks, regarded as wilderness areas) was in completely separate areas (QQ 622, 634). Back
127  See, for example, Professor Williamson on the traditionally bred Texas Cytoplasm corn, p 214. Back
128  As a resource for future breeders, so that they are not limited to varieties currently in production, but have access to the widest possible gene-pool. Back
129  Furthered both by Monsanto's acquisition of Plant Breeding International, Cambridge and by the agreement between Novartis and Hoechst during the course of this enquiry.  Back
130  The seed bag for Monsanto's Roundup Ready soybeans in the United States bears the message "These seeds are covered under U.S. patent 4,535,060 4,940,835 and 5,352,605. The purchase of these seed convey no license under said patent to plant these seeds. A license must first be obtained from Monsanto Company before these seeds can be used in any way." Back

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