Submission to the Scottish Parliament’s Health Committee Inquiry into the Health Impact of GM Crops

Submission to the Scottish Parliament’s Health Committee Inquiry into the Health Impact of GM Crops


The Royal Society of Edinburgh (RSE) is Scotland’s national academy of science and letters. Founded in 1783, it has a Royal Charter for "the Advancement of Learning and Useful Knowledge". Its Fellowship includes distinguished individuals from the Sciences, Arts, Letters, Technology, the Professions, Industry and Commerce. The Society is a wholly independent body and provides an important neutral forum for informed consideration of topics concerning the well-being of Scotland, with a third of its funding provided by grant-in-aid from the Scottish Executive and the remainder from a range of public, private and charitable sources. The Society’s diverse range of activities include organising meetings and symposia, awarding Research Fellowships, Scholarships and Prizes, and publishing learned journals. This response has been compiled by the General Secretary, Professor Andrew Miller and the Research Officer, Dr Marc Rands, with input from a number of Fellows with substantial experience in this area.


Extensive studies on the safety of GM crops in the environment, and on the safety of GM crop-derived foods have been undertaken, published and embodied in regulation of the technology for 10-15 years. No other agricultural process technology, or the food products derived from it, has been subjected to this level of debate and analysis. There could, in theory, be long-term effects on human health that have not yet been detected (OECD 2000a). There have been extensive study and scrutiny of the development of GM plants 15-20 years. GM foods have been available for less than 10 years. After seven years of widespread global uptake and practice, no risks to human health from GM crops have been demonstrated. Continued research and monitoring is essential to check the longer term situation.

There are a number of areas where there is on-going research and debate, including the level and significance of GM gene flow, the impact of GM crops on the environment, and the potential of GM technology in the future. The questions asked by the inquiry are now addressed below:

Should the Executive prevent GM crops trials from continuing on the grounds that it is against the precautionary principle to allow them to continue?

There is no scientifically proven evidence of any "threats of serious or irreversible damage" to public health. All globally available scientific evidence and regulatory approvals (since the mid-1980’s), together with practical experience of commercial-scale growing (200 million hectares over 7 years by 5.5 million farmers in 2001), and consumption of GM crop-derived foods have shown no impact or harm to public health. A number of National Academies of Science, the European Commission, Government watchdog Commissions and Agencies, have concluded that GM crops pose no additional threats or risks to humans compared with conventional crops.

It is important to recognise that science never generates absolute certainty but can only give a balance of probability in the light of current knowledge. Only through research and experimentation can risks be estimated. The lack of full scientific certainty should not be used as a reason for not doing something and it can never be certain that any course of action is without risk. To try to invoke the "precautionary principle" in the absence of substantiated risk would be wrong. However, there is uncertainty about the effects of long-term exposure, so the current precautions to ensure low levels of contamination from GM trials are sensible.

The European Commission, in February 2000, issued a communication on the use of the precautionary principle in the EU and internationally (European Commission 2000). It recommended:

"Where action is deemed necessary, measures based on the precautionary principle should be, inter alia:

  • proportional to the chosen level of protection,
  • non-discriminatory in their application,
  • consistent with similar measures already taken,
  • based on an examination of the potential benefits and costs of action or lack of action (including, where appropriate and feasible, an economic cost/benefit analysis),
  • subject to review, in the light of new scientific data, and
  • capable of assigning responsibility for producing the scientific evidence necessary for a more comprehensive risk assessment."

Is the risk assessment procedure for GM crops currently in place sufficiently robust from a public health perspective?

All of the GM crops which are currently grown commercially have been exhaustively assessed for food safety by public health authorities world-wide. Organisations involved include the United Nations Food and Agriculture Organisation, Organization for Economic Co-operation and Development, National academies of Sciences in America, UK, Brazil, China, India, Mexico and the Third World Academy of Science, the United States Institute of Food Technologists, Swiss Association for Research and Nutrition, American Society of Toxicology and affiliates of the American Council on Science and Health. GM food/crop risk assessment procedures exceed those applied to any other crop technology, and will no doubt be improved as more information becomes available.

There has been some discussion about the use of substantial equivalence but there is a consensus amongst toxicologists concerning its validity in the case of GM crops (Society of Toxicology 2002). Substantial equivalence provides a simple investigative structure whereby the safety of any novel food can be approached and is the start point for any investigation not the end. Currently the OECD (2000b) recommendations require detailed compositional comparisons between the genetically modified food and a non-GM counterpart, and where considered necessary because of the nature of the GM modification and on a case-by-case basis, toxicological testing of the novel trait (the protein) and long term animal feeding experiments coupled with detailed anatomical, biochemical and histological examination of the test animals. The OECD recommendations embrace the earlier requirements of the USA Food and Drugs Administration in the use of substantial equivalence and toxicological and feeding experiments to establish food and health safety. However the procedures of GM food testing continue to evolve and simplify as new scientific technologies emerge. Currently the RSE contains an archive of papers that describe animal feeding experiments with GM food, toxicological testing of introduced traits and comparisons of composition between GM and their non GM counterparts. This archive may be examined on request. However discussions concerning the development of substantial equivalence should not be confused with the safety assessments performed on the crops on trial in the UK. These products are considered as safe for consumption as their non-GM counterparts.

In October 2001 the European Commission published the results of the biosafety research it has supported over 15 years (European Commission 2001). Research on the GM plants and derived products so far developed and marketed, following usual risk assessment procedures, has not shown any new risks to human health beyond the usual uncertainties of conventional plant breeding. The Commission also concluded that the use of more precise technology and the greater regulatory scrutiny probably make them even safer than conventional plants and foods.

Are the guidelines to prevent conventional crops being cross-contaminated by GM crops adequate?

Limited pollen transfer can be expected between the same or related species-but will not occur between, for instance, between wheat and rapeseed. The question of transfer of invasiveness of traits to wild relatives has been well assessed for both vertical and horizontal gene transfer and it has been demonstrated that GM arable crop plants resistant to herbicides or insects are not more invasive than their conventional counterparts. One study (Crawley et al. 2001) compared the persistence of conventional and GM lines of four crop species over 10 years in 12 different habitats. In addition a recent report based on many measurements in Australia (Reiger et al. 2002) has shown that the highest level of cross-pollination movement from GM to conventional rapeseed was 0.07%. Given these findings, the current guidelines should be adequate, but it is only through research, of which the farm scale evaluations are a part, that such questions can be answered on a firm basis.

The farm-scale trials use herbicide-tolerant crops and none of the genes contained in the GM trial crops has been shown to pose a threat to humans. All have been thoroughly tested, and passed as safe through the regulatory process.

Should it be incumbent on the Scottish Executive to monitor the health of people living around GM farm scale evaluation sites?

The recent Royal Society of London report (Royal Society 2002) has noted that there was no formal assessment of the allergenic risks posed by inhalation of pollen and dusts. The route of exposure of the local population around a GM trial will be different from that for the UK population as a whole, for example, through inhalation of air-borne particles or through the skin from walking in the crop, rather than through diet (the level of acute exposure could also be higher). However, no practical monitoring programme will have the power to show health effects within a reasonable time scale. Experience from US strongly suggests that, if there are any health effects, they will be very small and long term. The most likely effects will be the result of anxiety. Hence, any proper study will need to include 'dummy' GM trial sites, which actually involve conventional varieties, so as to avoid a placebo effect.

In this context it should be noted that that the Scottish Office (as it then was) found difficulties in producing a protocol for assessing the possibility that allergies were triggered in people by the presence of nearby conventional rapeseed crops. There are also herbicide resistant crops commercially available which have been produced by ‘conventional’ techniques which involve mutation of the plant genome which would also have to be subject to the same investigation as those being proposed for GM crops.

Additional Information

In responding to this Inquiry the Society would like to draw attention to the following publications which are of relevance to this subject:

Crawley M J , Brown S L, Hails R S, Kohn D D, Rees M (2001) Transgenic crops in natural habitats. Nature 409, 682-683.

European Commission (2000). Communication from the Commission on the precautionary principal. Brussels, 2.2.2000, COM(2000)1 final. (

European Commission (2001). A Review of Results: EC-sponsored Research on Safety of Genetically Modified Organisms. Edited by Charles Kessler and Loannis Economidis. Office for Official Publications of the European Communities, L-2985, Luxembourg. (

OECD (2000a) Genetically Modified Foods: Widening the Debate on Health and Safety. The OECD Edinburgh Conference on the Scientific and Health Aspects of Genetically Modified Foods.

OECD (2000b). Report of the task force for the safety of novel foods and feeds. Organisation for economic and Co-operative Development. C(2000)86/ADD1. Paris.

Rieger M A, Lamond M, Preston C, Powles S B, and Roush R T (2002). Pollen mediated movement of herbicide resistance between commercial canola fields. Science 296, 2386-2388

Royal Society (2002). Genetically modified plants for food use and human health – an update. Policy document 4/02

Society of Toxicology (2002). The Safety of Genetically Modified Foods Produced Through Biotechnology, Position Paper, September 25th, 2002

World Health Organisation (2000). Safety aspect of genetically modified foods of plant origin. Report of a Joint FAO/WHO Expert Consultation on Foods Derived from Biotechnology. ( 2000.pdf)

World Health Organisation (2001). Evaluation of Allerginicity of Genetically Modified Foods. Report of a Joint FAO/WHO Expert Consultation on Allergenicity of Foods Derived from Biotechnology. ( /report20.pdf)


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