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From Green to Gene Revolution The Environmental Risks of Genetically Engineered Crops

Ricarda A . Steinbrecher

Many interest groups claim that an increasing world population cannot be fed unless genetically engineered crops are grown. Such crops, it is argued, will produce higher and better yields than conventional farming methods and have fewer adverse environmental impacts because the frequency, range and toxicity of weed-killer and pesticide applications will be reduced. Ecological risk assessments are said to indicate that several products can be grown safely on a wide-scale. In fact, genetically engineered plants are likely to increase the use of herbicides and pesticides and to accelerate the evolution of usuperweeds " and "superbugs". Crucially, major environmental risks associated with genetically engineered plants are the unintended transfer to plant relatives of the "transgenes" and the unpredictable effects. Risk assessments are limited and have primarily been based on an outdated understanding of gene behaviour.

Dr Ricarda A. Steinbrecher is a geneticist and coordinator of the Test Tube Harvest Campaign of the Women's Environmental Network, UK.

The Ecologist, Vol. 26, No. 6, November/December 1996

The major application of genetic engineering in agricul­ ture is food crops. Genes believed to determine spe­ cific traits — height, tolerance to frost or drought, and protein or fatty acid composition, for example — are spliced into plants from unrelated organisms, such as animals, other plants, fungi or bacteria, in the belief that the genetically engineered plant wil l exhibit the desired trait.1 For instance, antifreeze protein genes from winter flounder were added to tomatoes to create a fruit that could withstand colder tempera­ tures. Genetic material from chickens and silk moths have been spliced into potatoes to confer resistance to bacterial diseases. Engineered versions of most of the world's major food, fibre and fruit crops have now been produced, including corn, wheat, rice, potato, soyabean, sunflower, oilseed rape, potato, cotton and tomato.

In the past decade, these genetically engineered organisms have begun to leave the laboratory and enter the wider environment. Hundreds of field tests of genetically engi­ neered crops have been taking place since 1987, mainly in the United States and Britain.

In plant field release trials carried out between 1993-1994 in the 14 OECD countries, herbicide tolerance was the most common genetically engineered trait being tested (36 per cent); insect resistance was a close second at 32 per cent, while tests for virus resistance and quality traits (altered fruit ripening, for example, or increased solid content in fruits and tubers) accounted for 14 per cent each, leaving four per cent to "others" (including disease resistance and male sterility in plants).2

Chemical corporations head the list of those applying to field test genetically engineered crops. Between 1987 and 1993, they constituted 46 per cent of applicants in the United States;3 more than half these chemical company applications came from Monsanto,4 whose patent on the glyphosate-based weed-killer, Roundup, one of the best-selling herbicides worldwide, runs out in the year 2000.5 Seed companies, universities, government departments, food companies and small biotechnology companies account for the rest.6

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