It is an issue capturing attention from Paris to Peoria: Are genetically altered crops safe?
In Europe, a public backlash has forced many food companies to ban genetically engineered products from store shelves.
In the US, acceptance of the technology is widespread: Most of the nation's wheat and corn, for example, is genetically modified.
Now, however, new evidence is showing that some genetically altered crops can cause unintended consequences - which could spur more resistance to the booming bio-agriculture industry in the United States.
The latest sign: A study in the journal Nature that implies genetically modified cotton can promote resistance to pesticides in a well-known - and much feared - parasite.
The research comes in the wake of a study in May showing Monarch butterflies die after contacting pollen from genetically engineered corn.
Moreover, last week the country's largest baby food manufacturer, Gerber, announced it would stop using genetically engineered soy and corn products because of public concern - warranted or not - about safety.
"I think this is another small piece that tells us to be conservative," says Fred Gould, a North Carolina State University entomologist, of the news in Nature. "I think that what we need is a lot more science and a lot less talk."
Yet one group that is talking a lot more is environmentalists. They have seized on the latest research to buttress their claims that genetically engineered crops could pose a danger to people and the environment.
"There may be long term effects that we may not see for many years but could have serious detrimental impacts on brain development and organ development," says says Charles Margulis, a genetic issues specialist with Greenpeace.
But it is safe
For their part, the big biotechnology and agricultural companies argue there is no conclusive evidence that the crops are dangerous. In fact, they see them as beneficial to both the environment and consumers, since the crops require fewer pesticides.
"It's had a tremendous impact on the reduction of insecticide use," says Gary Barton, a spokesman for Monsanto Co., the big US chemical company. "The activist communities seem to ignore the nearly 1 million gallons of pesticide that hasn't been used on the cotton crops over the last three years. And that's just the cotton crop."
But it is precisely these claims, along with the lack of public opposition in the US, that make the Gerber announcement so surprising. Furthermore, Gerber's parent company, the Swiss pharmaceutical and agriculture conglomerate Novartis AG, has invested millions in developing the genetically altered plant strains that it now refuses to buy for Gerber baby foods.
Novartis executives say they want to make sure mothers retain their confidence in Gerber. In Europe, Novartis has tried to avoid conflicts with Greenpeace and other environmental groups. The company pulled baby food with genetically engineered ingredients off the shelf 24 hours after a Greenpeace request for information similar to the one sent to Gerber more than a month ago.
Despite the actions, Novartis and all other manufacturers of genetically engineered crops continue to maintain they're safe - a claim upheld by many food researchers in the US.
That's why each new study is being so closely scrutinized. In the findings published today in Nature, researchers at the University of Arizona document a flaw in a technique that causes plants to produce their own natural pesticide.
The study focuses on the fight against the pink bollworm, a pest that preys on cotton. Scientists have been splicing into cotton -as well as corn and other plants - a gene that produces a bug-killing chemical. Organic farmers have sprayed this bacteria on crops on rare occasions as a safer alternative to chemical treatments.
But the pests can develop a resistance to the bacteria. To counteract this, scientists plant genetically altered crops alongside regular crops. Under this "refuge strategy," bollworms that eat the altered crops - and eventually develop a resistance - will breed with bollworms that have not. The result is a slowing of the generations of insects that inherit a resistance.
Here's the problem: The life cycle of insects eating the genetically engineered cotton is delayed five or six days, altering their mating cycles. As the Arizona researchers point out, this may undermine the refuge strategy - and thus diminish the effectiveness of the natural pesticides.
This prospect especially worries organic farmers, who often use the natural pesticides as their last line of defense against crop-destroying pests.
Despite these concerns, few scientists advocate a ban on the development and use of genetically engineered crops, which farmers are already planting in vast amounts. But some do say the bollworms and Monarchs are evidence that a go-slow approach is warranted. "This is just one more of those studies that shows that all the ideal assumptions are not being met," says Mr. Gould.
(c) Copyright 1999. The Christian Science Publishing Society