It's a modified sort of debate

YORK people are being given the chance to take part in the national debate that will determine whether GM crops should be grown commercially in the UK. City of York Council is organising an open public debate at the Priory Street Centre at 7pm. Chaired by Coun Andrew Waller, the council's deputy leader and executive member for environment and sustainability, the debate will bring two leading experts in the field head-to-head.

Arguing the case for GM crops will be Dr Julian Little of Bayer Cropscience. Speaking against GM will be Dr Sue Mayer, director of Genewatch UK, a not-for-profit group which monitors developments in genetic technologies.

Members of the audience will also have the chance to ask questions and fill in feedback forms, which will be returned to the Government's national GM Public Debate steering group.

Kristina Peat, sustainability officer with City of York Council, says: "GM is one of the biggest issues facing our society today and has the potential to have a huge impact on our lives. The debate will give local people a chance to hear views from experts as well as get involved in the discussion themselves."

To get you in the mood, we put a few questions on GM crops to York scientist Prof Ian Graham of York University's Centre for Novel Agricultural Products (CNAP) and Alan Robertshaw of York Green Party. These are their answers:

What are the potential benefits of GM crops?

Graham: Many and varied, for industry, society and the environment. Some of the work is to engineer oil seed metabolisms to produce new types of vegetable oils that can provide an alternative to petrochemicals. You can also modify the type of oil that plants are producing by introducing a single gene so the plants make a very useful lubricant or something like a biodegradable plastic.

Research groups are also working on producing oral vaccines that don't need to be injected - you dry the plant material and produce a tablet form. And we are continuing to research producing plants with fatty acids such as fish oils that have health benefits.

Robertshaw: Until they are proven to be safe and healthy we don't want to discuss benefits that may be available.

What are the

potential risks?

Graham: It is impossible as a scientist to say there is no risk, because scientists don't say that. In terms of probabilities, there is no reason to suppose that any of the GM crops being produced pose any high risk to human health. The best evidence is that 200 million Americans have been eating GM for the past ten years and there has not been a single case of as much as a tummy upset.

Farm-based field trials are going on in the UK to produce herbicide resistant crops. People opposed to GM say we're going to have super weeds taking over the world. But the bottom line is the weed would only be resistant to one herbicide. This is not going to give this weed any advantage at all in the environment. There are dozens of herbicides, and it will only be resistant to one. So it is very difficult to envisage a scenario where this is going to make a super weed.

Robertshaw: Nobody knows what the possible long-term consequences are. There may not be any, we accept that.

But when we don't know, why risk it? Until there is long-term evidence that they are safe, I don't think we should accept them. If they are contaminating other crops we could wind up with super weeds, and also other crops infected with GM. There may be no organic crops left.

How are genetically-modified plants produced?

Graham: There are two main ways. There is a bacterium in the soil, agrobacterium tumefaciens, which naturally transfers DNA into plants. These bacteria are every day happily producing transgenic plants in the wild.

Scientists can grow these bacteria in flasks, take their favourite gene, put it into the bacteria using standard lab techniques, expose the bacteria to plants in the lab and the bacteria will transfer DNA into the plant.

There are some plants that this bacterium does not transform - grains such as maize, wheat and rice.

Scientists have come up with a way of using very dense particles, such as gold, coating these with DNA and then shooting them at the leaf of a plant.

When they pass through they leave some DNA behind, and it is taken up into the plant's nucleus.

Which GM crops are grown in the UK?

Graham: In the UK mainly sugar beet, maize and oil-seed rape.

What foodstuffs in British supermarkets include GM product?

Graham: There could be trace amounts in a wide range of foods, but very small.

Robertshaw: There is a likelihood that a lot of foodstuffs have GM in them, especially those imported from the States, because it is difficult to track them.

How real is the risk that there could be cross-contamination to non-GM crops?

Graham: Buffer zones are established to prevent cross-pollination. The width of the buffer zone depends on the crop. For a new gene to spread and become established it has to confer an advantage.

If these genes are not conferring an advantage above being resistant to a single herbicide (one out of many) they are not going to spread and become established.

Robertshaw: If you have two crops growing next to each other, or even ten miles apart, it is almost certain that there will be cross-pollination.

Demand for organic food is rocketing. This is what people want and where the Government should be investing. Planting GM crops threatens this valuable area of agriculture and health because once they are planted they will spread by wind, insects and birds to randomly contaminate non-GM crops and it will be impossible to verify any crops as organic.

In the light of public opposition to GM crops, what should the Government do now?

Graham: There has been new legislation adopted by the EU parliament essentially giving a green light to different member states to grow crops. Individual countries will have the freedom to decide.

The Government should continue to be aware of the potential of the technology.

If we turn our backs on it we are going to turn our backs on a lot of opportunities, not necessarily in the short term but in the longer term.

More research needs to be done and in the UK we are fortunate in having some of the best research in this area that is going on in the world.

The danger is that if we turn our backs on GM then we will be turning our backs on research as well.

Robertshaw: The Government needs to listen to the majority of people of this country who have clearly said that they do not want GM crops until convinced by the science that they are safe and that we need them and not that we are having them foisted on us because they are going to make a small number of people very rich and powerful.

Updated: 11:00 Tuesday, July 15, 2003