By Rachel Carson, author of Silent Spring
The Ithaca Journal via Checkbiotech.org

"As crude a weapon as a cave man's club, the chemical barrage has been hurled against the fabric of life."

Debates over genetically modified crops are reminiscent of the controversy surrounding the introduction of Pasteurization in the early 20th century. Pasteurization was seen as an unnatural process, which it is. Yet its routine use probably has spared millions of people from serious illness or death.

Genetically modified organisms, or GMOs, are being used to reduce the use of synthetic or natural pesticides in both industrialized and developing countries. Many critics question the safety and effectiveness of such genetic engineering, just as people in the past worried about Pasteurization.

A recent issue of The Economist cited a report by the International Service for the Acquisition of Agri-biotech Applications, an Ithaca-based non-profit firm that noted fully 9 percent of the world's maize crop is destroyed by insects at a cost of $5.7 billion while $550 million is spent on insecticides. In trials of genetically modified maize crops, yields increased by 23 percent in China, 24 percent in Brazil and up to 41 percent in the Philippines, according to The Economist.

Rachel Carson's "Silent Spring," published in 1962, outlined how the extensive use of chemical pesticides was endangering a wide range of organisms, including humans. It inspired agricultural practices, legislation and research to identify methods of controlling pests without using synthetic pesticides.

One alternative to such pesticides comes from a common bacterium, Bacillus thuringiensis, which is commonly called "Bt." This bacterium has been used for more than 50 years as an insecticide by organic and conventional growers with limited use. However, when scientists identified the Bt genes and were able to engineer them into plants, this bacterium's proteins became a major insecticide that is now widely used throughout the world to control troublesome insects.

When the Bt genes are engineered into a corn crop, for example, those plants express certain proteins that control pests such as the European corn borer. Thus, the need for synthetic pesticides can be reduced or eliminated and yields can increase. In fact, the trials cited in The Economist used Bt-modified maize.

Despite such potential, fears remain about genetically modified crops. For example, in a preliminary laboratory study which was criticized by many scientists, pollen from corn that was modified with Bt was fed to monarch butterflies with lethal consequences. Since that work was confined to a laboratory, it would be "inappropriate to draw any conclusions about the risk to Monarch populations in the field based on these initial results," according to Congressional testimony by Anthony M. Shelton, a professor of entomology at the Cornell University agricultural experiment station in Geneva.

"I'm a child of the 1960s and I read Silent Spring. Rachel Carson talked about Bt and how it could be helpful in containing insect populations in a sustainable fashion," Shelton said. "As an entomologist, when I look at what Bt can do, there are some very positive things."

One example is sweet corn. If you buy sweet corn in New York during the spring months, it generally comes from Georgia or Florida where there are tremendous pest problems and they have to treat their plants with numerous pesticides.

"However, if one is to use sweet corn that is expressing the proteins from Bt, essentially the corn does not have to be treated at all by any broad-spectrum insecticides and certainly it would be my choice to eat that," Shelton said.

Any new technology -- or a continuation of older technologies -- will have potential risks that should be thoroughly researched. To date, the risks of Bt-engineered corn and other genetically modified crops have not turned up any proven, significant health effects. It would be a mistake to make GMOs the subject of a witch hunt that would mislead the public and deter further research into this emerging technology.

Copyright © 2004 The Ithaca Journal