The Scottish Government

Your Questions Answered

All living things contain genes. Genes can be seen as the building blocks that give us our particular characteristics. They determine, for instance, the colour of our eyes or the number of petals in a flower. It is the interaction of the 'set' of genes in every cell of a particular living thing that will give it its particular identity.

While it is possible for plants to produce seeds with new characteristics through pollination of one plant with another that has those characteristics, there is no guarantee that a particular trait (like improved taste) will be found in the next generation. Using artificial methods, modern agriculture has made the process of producing seeds with desirable or useful characteristics more reliable. Genetic modification is a more precise way of achieving this goal. A GM plant has one or more characteristics changed intentionally by either adding or removing particular genes to or from its existing genetic makeup. Where genes are added they may come from completely unrelated species, perhaps not even from plants. It is convenient to talk of 'plant genes' or 'animal genes' meaning genes sourced from plants or animals. However, it is genes that make an organism what it is and not the other way round. That is to say, there is not something intrinsically 'fruity' about a gene found in fruit. Indeed, an estimated 30% of the genes found in humans are also present in tomatoes.

What is the purpose of the trials?

The GM field trials (sometimes called the farm scale evaluations) are designed to assess the impact on the environment of the agricultural practices used to grow certain GM crops on a commercial scale. Farming these particular crops requires the application of herbicides in ways which have not been used in fields of this size before. This has given rise to some concerns about whether growing GM crops could be more detrimental to farmland wildlife than conventional agriculture. The trials will help to assess this. They are not testing the safety of the GM crops. These particular crops have been grown without any difficulty for many years in the laboratory, in greenhouses and on small-scale research plots. If approved, 2002 would be the third year of field trials for the crops in Scotland. Only when individual crops have satisfied the independent scientific experts that they do not pose a threat to human health or the environment are they considered for planting on farms.

While these trials are taking place, government has agreed with the industry that no GM crops will be grown commercially in this country at least until the trials are complete and more is known about the potential impact on our environment of growing these crops.

What actually happens on the farm?

Fields representing a wide range of conditions typical of British farms are selected and planted with a GM crop in part of the field. The rest of the field is planted with a non-GM crop of the same species for comparison. The farmer looks after both crops using normal farming practices. The non-GM crop is treated with the usual range of weed and pest controls, while the GM crop may also be treated with a specific herbicide to which it is tolerant.

During the growing season, field researchers monitor the number of weeds and insects (including bees and butterflies) in both the GM and non-GM sides of the field and in the field margins. Any variations are recorded. By doing this, it will be possible to tell whether there are any significant differences in the populations of key farmland species in the GM and non-GM sides of the field. Other researchers also look at how pollen travels from the GM crop.

What kinds of crops are being grown in the trials? In what way have they been modified?

A number of GM crops are being grown as part of the UK trial programme but only oilseed rape (both spring- and autumn-sown varieties) is grown in Scotland. The oilseed rape is a genetically modified hybrid which has been made tolerant to a specific herbicide. In all other respects the crop is identical to non-GM rape varieties. It has been grown commercially in North America for about 6 years, but only for research in the UK since the early 1990s.

It is not possible to treat all applications of GM technology or all GM crops as a homogenous category. Each GMO must be considered in light of the particular modifications it incorporates and on its own merits. It is for this reason that the Executive's expert scientific advisors assess each application to grow a GM crop for research purposes on an individual basis. Only applications that satisfy these expert advisors as to their safety are considered for release in Scotland.

How big are the trials?

Up to 15 hectares of the GM variety may be grown on individual trial sites. At the beginning of 2002, 178 sites in the UK had grown crops on the programme. 12 sites were in Scotland.

Site selection takes place independently of government. Growers wishing to participate firstly register their interest with the seed company and the details are then passed to the researchers who are conducting the study. The researchers need to be satisfied that an individual site is suitable for this type of research work before recommending it to the body which oversees the trial programme. This independent body, the Scientific Steering Committee (SSC), includes members from the RSPB, English Nature and the Game Conservancy Trust. It will only endorse those which it considers will provide a representative set of results to meet the objectives of the trial programme. Results are needed from a wide range of areas and farm types. The SSC's list of proposed sites is passed to Ministers for approval.

Who is doing the research?

Independent scientists are undertaking the fieldwork and compiling the results. The scientists working on Scottish trial sites are from the Scottish Crop Research Institute, an organisation based in Dundee with an international reputation for its expertise in this subject.

The harvested GM crops from these trials have been destroyed because the crops are grown purely for research and do not have the necessary approvals for consumption in this country.

How long will the trials last?

2002 is the third and final year of the programme. Spring crops will be planted between March and May and harvested in the autumn. Autumn 2002 sowings will be harvested in late-summer 2003. Individual fields are only used once, although sites are monitored for a further year after harvest.

Results from all the UK trial sites will be collated upon completion of the programme. Thereafter, results from each crop will be assessed by other experts in the field and published in a respected scientific journal. It is expected that the findings will start to be made public in spring 2003 and that everyone will have an opportunity to comment on them.

Has the crop been tested?

The crops which are grown in these field trials have been grown under research conditions in this country for around a decade. The GM oilseed rape grown in these trials has passed all the necessary steps which check its safety for humans and the environment and an application has been submitted for it to be granted commercial approval in Europe. The Executive and the UK Government have agreed with the industry that no decision will be taken on that application at least until the results of these field trials are known. However, GM herbicide-tolerant oilseed rape is grown extensively in other parts of the world. World-wide, an area twice the size of Britain was planted with GM crops in 2001.

How do we know the crop won't harm animals or humans if accidentally eaten?

All applications to grow or market a GM plant must include information to enable a thorough assessment of the plant's potential to harm animals or humans. In the case of these herbicide-tolerant oilseed rape crops, this safety assessment considers the possible effects on wildlife including birds, bees and other insects, small mammals and on humans. The independent experts who advise Ministers on every application have the necessary expertise to come to an informed view on each application. Approval would not be granted if it was suspected that there could be harm for human health or the environment.

Where can I see the evidence that these crops are safe?

Applications for consent to grow GM crops must include a wealth of supporting information, including conclusions from earlier tests. This is considered by the Advisory Committee on Releases to the Environment (ACRE) who have concluded that these field trials do not pose a significant risk to the environment or human health. The information to support this and ACRE's advice to Ministers is placed on a Public Register at DEFRA, Ashdown House, 123 Victoria Street, Westminster, London SW1E 6DE. Copies of Register entries relevant to Scottish interests are held by the Executive in Edinburgh.

If it is safe, why are we testing it? Won't it be too late if there is a problem?

Although the authorities are satisfied that these particular crops do not themselves represent a threat, some environmental organisations felt that more information was needed about the effects of the herbicide practices associated with their use. It is in response to these concerns that the trials have been introduced to examine in detail what impact such practices might have. The number of trial sites represents a tiny fraction of the area which the crops might cover if commercial approval was granted and it seems sensible to look at potential impacts on this scale at this stage. If there was to be an adverse impact on certain types of plant, insect or animal life, this should be better able to recover if confined to an individual field.

Are the herbicides used on these crops new or more dangerous than other kinds?

The herbicide to which the GM oilseed rape is tolerant is glufosinate ammonium. This is a broad-spectrum herbicide, which means that it will usually eradicate any foliage with which it comes into contact. It has been approved by the pesticides safety authorities for use in conventional farming and can be bought in garden centres, often for keeping paths clear of weeds. Although it is no more toxic than other herbicides of its type, the use of glufosinate ammonium in association with herbicide-tolerant GM plants could involve applications in ways and at times of the growing season not previously experienced on a field scale. Examining the possible implications of these new practices is the key purpose of the trials.

What rules control the trials? Who checks the trial sites?

GM crop trials are controlled by European and UK legislation. In Scotland this legislation is the responsibility of the Executive, who appoint qualified inspectors to monitor individual sites. The Scottish inspectors are from the Scottish Agricultural Science Agency. Each approval is subject to conditions: such as the maximum area which may be planted or the distance between the GM crop and other closely-related species. Audits and inspections enforce these statutory conditions. Infringements could lead to penaltie

How do I benefit from these crop trials?

There is no immediate benefit to the consumer from these trials. Claims have been made that, if given commercial approval, herbicide-tolerant GM varieties could result in cheaper produce, or crops that would require fewer inputs and entail less impact on the environment than conventional production. However, the interest of the Executive is not concerned with benefit, but is focused upon ensuring that any plantings which take place do not pose a safety threat to human health or the environment. Ultimately, the Executive takes the view that it is in the public interest to subject these crops to this type of thorough examination before any decisions are taken which could lead to their widespread use in our countryside. It is considered that such important decisions should be informed by factual evidence and that sound decisions will be to everyone's benefit.

Why should we trust science, when it has been wrong before and even scientists seem to disagree about GM?

The Executive's responsibility is to protect human health and the environment and to do so on the basis of the strongest interpretation of the evidence. We are assisted in this by experts from a wide range of scientific fields, most significantly on the Advisory Committee on Releases to the Environment. ACRE is an independent body whose role is to make an objective assessment of the research on a particular GM crop and advise government on the basis of its conclusions. We always consider carefully any research whose conclusions appear to challenge the advice given to government.

It can be frustrating that science cannot deliver certainties and it may undermine public confidence when scientists appear to have reached wrong conclusions in the past. However, it does not make sense to abandon the advice of scientists because of this. It is not possible to be 100% certain of anything. Science cannot prove the safety of something, only demonstrate the lack of harm. A precautionary approach is not one that avoids any action without absolute proof of safety (this being impossible), but one in which action proceeds in proportion with the state of knowledge about the potential risks. This is the approach adopted in the case of the farm trials. The current state of scientific knowledge permits the Executive's expert advisors to conclude that the probability that the GM crops in the UK farm trials will cause harm is so remote as to be inappropriate grounds for not conducting the trials. There is always a degree of risk in everything we do, but GM crops are only granted approval when that risk is considered to be so low that it is no more significant than that of growing conventional crops.

Can the GM crops pollinate non-GM plants?

The oilseed rape growing in the trials produces pollen that can be carried by insects or the wind. Therefore, the possibility of cross-pollination occurring with certain non-GM plants cannot be ruled out entirely. However, oilseed rape can only breed with a few closely-related species. The potential for cross-pollination has been considered by the Executive's expert assessors and their advice is that it does not pose a safety threat.

Cross-pollination can only occur when the pollen lands on a compatible related species, while the flowers of that species are fertile and the pollen itself is still alive. Oilseed rape pollen has a short lifespan. Most of it will pollinate flowers that are less than a couple of metres away. Any evidence of pollen having travelled outwith a GM trial field is not the same as evidence that fertile pollen has travelled, or that cross pollination can, or will, take place. Separation distances between the GM crops and related crops are used to minimise the potential for cross-pollination. These separation distances are based on those used successfully in conventional farming, where farmers are just as keen to prevent breeding between different crops and varieties. Separation distances are about enabling different systems of agriculture to coexist in Scotland and do not reflect any doubts about safety.

Scientific advisers have also considered the possibility of cross-pollination between GM oilseed rape and the small number of wild plants to which it is related. The locations of any wild populations of relatives growing in designated areas are taken into account when siting GM crop trial. However, cross pollination of a wild relative by the crops in these trails is not in itself a safety threat. Scientific advisors do consider, however, whether the modified gene - in this case for resistance to a specific herbicide - is likely to remain in populations of plants it has entered through cross-pollination. In order to persist in a population the herbicide tolerance gene would have to give those wild offspring that had acquired it an advantage over other those which had not. This gene does not give a plant a competitive advantage unless it is exposed to the relevant herbicide. If a gene does not confer an advantage, it will quickly be lost from a population. Wild plants would not normally be exposed to this herbicide, so it is most likely that the herbicide tolerance gene would be removed from wild populations under the pressure of natural selection. The presumption, sometimes expressed, that if the GM oilseed rape pollinates a wild relative, the modified gene is somehow 'on the loose', to persist in the environment for a long time is misplaced.

Can genes 'escape' from the GM crops by means other than reproduction?

Concerns are sometimes expressed that genes that have been inserted into a GMO may 'escape' from the organism, for instance, in the digestive systems of animals who have eaten it, or when they decompose in the soil, and then be picked up by gut or soil bacteria. This kind of gene movement is termed 'horizontal gene transfer'. Horizontal gene transfer is not an issue specific to GMOs; it can also occur between non-GM organisms. It is worth bearing in mind that much of what we eat, and every plant or animal that decomposes in the soil, contains genes. We do not tend to worry that our own digestive bacteria might acquire pig genes whenever we eat a bacon sandwich.

While there is some evidence of horizontal gene movement under specific laboratory conditions designed to be artificially conducive to the take-up of particular genes, there is no evidence of horizontal gene transfer occurring from the varieties of GM crops being grown in the farm trials. The probability of such gene transfer occurring under natural conditions is extremely low. Furthermore, even if it was to occur, it would not pose a safety threat. These crops have been modified to be resistant to the herbicide, glufosinate ammonium. In the judgement of the scientific experts, it is not possible to conceive of a risk to human health or the environment from a bacterium that had acquired this herbicide resistance trait. The advice of the Executive's scientific assessors is that there are no grounds for concern in respect of horizontal gene transfer from the GM crops being grown in the Scottish farm trials.

Will GM material be collected by bees and end up in honey?

Like most flowering plants, the GM crops are likely to be visited by foraging bees. The possibility exists therefore that honey could be produced by bees that have visited a GM crop. The sugars that make up honey are not themselves 'GM' and are the same whether the bee has been feeding from GM or non-GM plants, or indeed from a non-food plant. The part of a GM plant that does contains genes and which might inadvertently get into honey in minute quantities, is pollen. However, the Government's food experts are satisfied that, even if it was to get into honey, pollen from approved GM crops does not pose a safety threat to consumers (or indeed to bees). The GM oilseed rape growing in the trials is modified to make three enzymes and only two of these are ever present in the pollen. Furthermore, they are only expressed in very small amounts in the developing pollen during early flower development. Both of these proteins, their properties and what they will interact with are well known and judged not to be harmful to either humans or insects such as bees.

Will the pollen from the GM crop cause allergies?

It is recognised that oilseed rape pollen of any kind can cause allergic reactions such as hayfever or asthma. However, there is no reason to believe that the GM being grown is any more allergenic than its non-GM counterparts. The Advisory Committee on Releases to the Environment (ACRE) have specifically considered this issue and concluded that this GM oilseed rape pollen is a very low allergenic risk. These crops would not be grown in Scotland if it was felt they posed a threat to human health.

Will organic farmers lose their organic status as a result of these trials?

The rules which apply when these GM crops are grown include separation distances. These are intended to minimise the possibility of pollen from a GM plant successfully pollinating related species, including organic species. EU standards prohibit the use of GM technology and other non-organic elements in organic farming, but do not prevent the sale of organic produce which has low levels of GM material present unintentionally. There is no legal or scientific reason why organic status should be threatened by these trials and our aim is that this should continue. We are not aware of any crop losing its organic certification as a result of the 178 field trials which had taken place in the UK prior to 2002.

How will the crop trials affect my organic garden?

The risk to local organic gardeners has been assessed as being effectively zero. Only if a gardener happened to be growing organic oilseed rape would there be any real possibility of successful cross-pollination, although the distances involved would make even this unlikely. The likelihood of oilseed rape cross-pollinating domestic brassicas is very low. But to do so in the context of a domestic garden would require the gardener to permit their vegetables to flower, those flowers to be fertilised by pollen from the GM crop, seed to be shed into the soil and then the resultant plant to survive weeding and reach maturity in the following growing season. Such a plant, even were it to grow, would clearly be a weed and not easily confused with an intended crop. Even if such a highly improbable chain of events were to occur, it is important to bear in mind that the expert view is that it would not pose a safety threat.

How can I have a say in the crop trial process?

The Executive welcomes comments at any time from members of the public on any aspect of these trials. The Executive has gone to great lengths to be satisfied that an approval for the growing of a GM crop will only be granted after a thorough scientific assessment has concluded that it is safe to do so. If, however, there is any evidence to suggest that this scientific judgement is invalid for a particular crop or a particular site, Ministers will have no hesitation in investigating that evidence and will use their powers to halt a trial if this is merited. Some people simply do not wish to see GM crops grown in their area for wider ethical reasons or because of perceived socio-economic implications. The current legislation, however, only permits Ministers to take account of views backed by verifiable evidence of any direct physical harm to the environment or human health caused by the GM plant. Nevertheless, the Executive would welcome questions or comments on any of the issues which are raised by GM field trials.

The GM Co-ordination Team can be contacted at gmoteam@scotland.gov.uk or by writing to: GM Co-ordination Team, Scottish Executive, 1-H76 Victoria Quay, Edinburgh, EH6 6QQ