Using this technique, scientists copy a gene from one organism and add it to another to create a new plant with properties not found in nature. The practice has grown rapidly, says Anthony Shelton, a professor at the department of entomology (the study of insects) at Cornell University in Geneva, N.Y. And it has been highly controversial. Activists around the world claim that genetic engineering is a threat to both nature and human health. And the European Parliament recently approved tough rules on genetically modified products requiring them to be clearly labeled, among other regulations.
That's a temporary hurdle, contends Shelton, who has written more than 300 articles on agricultural pest-management techniques, including those accomplished with genetic engineering. On July 3, he spoke to BusinessWeek Online Reporter Olga Kharif about genetic engineering in agriculture. Edited excerpts of their conversation follow:
Q: How much of the food in grocery stores today is genetically engineered?
A: Many of the [items] produced with corn or soybeans are the result of genetic engineering. It's also used in the production of cotton and papaya. [A big component of] genetically engineered plants is pest control. About 30% of the corn grown in the U.S. is genetically engineered to fight insects.
Q: How does that work?
A: A gene from a bacterium has been incorporated into the corn plant's gene. That corn starts producing a protein from this bacterium. If an insect starts feeding on the corn, it ingests this protein, which is toxic to insects. It's not toxic at all to humans. This bacterium has been used as an insecticidal spray for more than 50 years by both organic as well as conventional growers. It's not a great insecticide when used as a spray, but when the genes that produce this protein are incorporated into a plant, the proteins become very effective.
Q: Do you expect genetic engineering to be used on more types of crops in the future?
A: A number of different crops are waiting to be commercialized. The majority are designed to reduce the amount of synthetic insecticide and other pesticides used to protect the crops. Tomatoes, potatoes, peanuts -- most of the major crops -- are being tested for attributes that would allow for pest control.
Such pest-management crops might not be seen as beneficial by the public, despite the fact they reduce the use of more hazardous pesticides. However, what if food crops were developed that would lower people's cholesterol? Make us slim down a little bit? Contain more nutrients, such as vitamins and minerals? These products are coming onto the market, also.
Other products are also being developed: plants that will be able to clean up toxic waste, trees that will have higher production levels of useful wood fiber.
Q: How safe are these products?
A: The public has requested that the amount of pesticide used in agriculture be reduced. And genetically engineered crops on the market right now reduce the amount of pesticide. In the case of insect-protected plants, the bacterium used has been sprayed on the fields for decades and is considered safe for humans and nontarget organisms. I think the alternatives are much less safe.
More than 75% of the cheese that's consumed in America is a product of genetic engineering. In the manufacturing of cheese, you need a particular enzyme that will help form the cheese. What people used to do was take this enzyme out of the gut of an animal. This technique had its health risks, such as spreading viruses. But now, this enzyme is produced through genetic engineering and added to milk for the production of cheese.
Nothing is 100% safe -- everything has risks and benefits. What you try to do with any technology is weigh the risks and benefits. You have to look at each product separately. The scientific body of evidence indicates that, for the products on the market right now, the benefits far outweigh any
potential risks.Q: And what's the impact of genetic engineering on nature?
A: I came into entomology because I was a child of the '60s, and I have a strong environmental background. I think that the products out there -- for fighting insects, weeds, and for disease management -- are very healthful to the environment compared to the way that these pests would have to be managed without genetic engineering.
Q: Is cross-species genetic engineering more dangerous?
A: You just really have to look at the particular product that comes out of that. Let me give you an example: To try making tomatoes frost-resistant, scientists thought about taking a gene from a flounder -- it's a cold-water fish -- and putting it into a tomato. Some people might say, "Well, that's crazy idea. I don't want fish genes in my tomatoes!" But it's actually an interesting case.
The gene from the flounder that caused the tomato to be cold-hardy is probably the same gene as from an alpine plant growing in Switzerland, which allows that plant to be tolerant to cold weather. Would it be more acceptable to take the gene from a plant rather than the flounder, even though molecularly, it's the same gene?
Q: What are the cost benefits of genetic engineering?
A: Genetic engineering can reduce the costs and environmental hazards of managing pests, which can be very high. Much of the sweet corn that's grown during the winter months and the early spring comes from Florida. A particular pest down there is very difficult to control, the fall army worm. Growers may spray anywhere from 15 to 30 times with foliar insecticides to control this particular caterpillar. But with sweet corn that has been genetically engineered, they only have to spray it once.
With spraying, you destroy beneficial insects in the field. You expose workers to higher levels of toxicants. You have potential for ground-water pollution. But with genetically engineered sweet corn, you don's have these problems. I'd certainly rather eat sweet corn that has been genetically engineered for insect control than the corn that has been treated fairly heavily for insect control.
Q: What's the outlook for genetically engineered foods in the U.S. and other countries? Europe has been especially resistant.
A: In 1996, when genetically engineered crops first came onto the market, they were grown on 4.3 million acres. Now, they're grown on 145 million acres worldwide. That's tremendous growth, and each year, the acreage continues to go up. There are 16 countries now growing such crops, and the adoption will continue to grow.
Once the Europeans have done more testing, they'll adopt it also. In the early 1900s, when pasteurization first was used to reduce microbial contamination in milk, it was very controversial -- despite the fact that it tremendously reduced the rate of infant mortality. When frozen food was first being produced, some states tried to ban it based on the belief it was unhealthy. Nowadays we take pasteurization and frozen food for granted. I think the same will happen with biotechnology.