Hedging our bets

Mick Fuller, reader in crop improvement at the Seale-Hayne Faculty of Agriculture, Food and Land Use at the University of Plymouth, sees both pros and cons to the development of genetically modified crops

The science behind genetically modified organisms (GMOs) is part of the molecular biology revolution of the 1990s and one of the first tangible commercialisations of this revolution. But misrepresentation of the facts, combined with a lack of consumer confidence in scientists and politicians, means that GM crops have become the latest major food scare.

GM crops are the result of using techniques of direct gene transfer to produce a 'transformant', followed by standard plant breeding to ensure that the gene is stable and multiplies without any problems. Only the uniformly expressed and effective lines are carried forward to produce a new variety. A gene can be taken from a completely unrelated organism and placed into a plant. Often-cited examples are arctic flounder anti-freeze genes or jellyfish fluorescent genes being put into plants. More commonly, plant-to-plant transfers are being used between unrelated species. The major difference between this and the process used by plant breeders over the past 30 years is that the GMO approach now allows small bits of DNA to be freely transferred between species.

Britain and now Europe have the most stringent regulatory process in the world for GM crops. Biological safety committees, the Health and Safety Executive, the Advisory Committee for Releases to the Environment and the Advisory Committee on Novel Foods and Processes are involved in this process, as will be the government's new Food Standards Agency. All of these regulatory authorities are concerned with risk assessment (both human health and environmental risks) and, while exact consequences can never be known, release for trials only proceeds when risk is judged to be very small.

One of the problems with GM crop risk assessment is the crops' unpredictable interaction with nature. This is a major campaigning point for environmentalists, but is it any more dangerous than releasing new conventionally bred varieties? Looking at the case for herbicide resistance, we already have herbicide-resistant weeds in our fields in Britain, but there is no evidence that these populations pose a serious environmental risk - only an agricultural irritant. As for danger to human health, the situation is probably that there is a very, very low risk, provided that good assessment and screening are undertaken. What matters is whether the perceived benefits outweigh the risks.

But if there are unknown risks, however small, do we as a society need to take them? Do we actually need GM crops? Farmers are reliant on plant breeders to bring out new varieties with disease resistance, pest resistance, virus resistance, better quality, better standing power, and so on. There is a massive turnover of varieties with some, like wheat, having a useful agricultural life of only about three to four years before it is superseded, or its disease resistance breaks down and the wheat becomes useless.

One consequence of a lack of new varieties is that more pesticides will be needed to protect crops. GM crops certainly offer opportunities for reducing pesticide use in agriculture - in America the savings on the use of insecticides in maize and cotton in the past two years run into millions of gallons. Many of the targets for GM research aim to improve agricultural efficiency, making it easier or cheaper for farmers to grow their crops.

But weighing up all the pros and cons it is probable that Western developed society doesn't really need GM crops. We already have good quality in most crop products, we have refrigerated storage and transport, we already have overproduction and we have a stable population. The developing world, with its increasing population and declining agricultural land fit for production, should be considered from a different perspective. GM crops offer great 'hope' of being able to overcome crop sensitivity to drought or salt, and to give disease and pest resistance without the need for pesticides. But here there is a classic problem. GM technology is almost exclusively owned by the private sector. This is an expensive technology of the developed world, which appears to have more scope for assisting mankind in the developing world...yet those who need it may not have the ability to pay for it!

In America GM food has been a major success, and millions of acres of GM crops have been grown. In the Far East GM crops are becoming a major success story - China has embraced the technology with open arms as a major contributor to coping with its growing population. Problems arise in Britain when we realise that food processors use large quantities of US crop by-products in our food and in our livestock feed. The lack of concern and reduced regulation in America means that all of these by-products have been mixed with non-GM supplies and therefore cannot be guaranteed GM-free. So we don't have the luxury of being able to label confidently to allow freedom of choice.

The whole GMO issue is confused, with discussions about agri-business, third world development, the global food market and the growing conviction that nature knows best. What is certain is that we cannot all return to nature, slash and burn agriculture, or all become organic consumers and continue to pay the same prices for food that we currently enjoy. We have to have trust in our regulatory bodies and the scientists, ecologists and food specialists who sit on them, and continue to demand, wherever possible, a right to choose.