Few Federal Checks Exist on the Growing of Crops Whose Genes Are Altered
By Carol Kaesuk Yoon
For most of the 30 years Bernie Thiel has been growing squash, he has battled an invisible but potent adversary: viruses that can turn his neat rows of sunny-yellow vegetables into a mottled, sickly green harvest.
"When you see a virus in your fields, it makes you sick," said Thiel, showing a visitor a patch of ruined squash in his fields in Idalou, Tex., outside Lubbock. "There is no cure for it. You're done."
This year, however, Thiel fought back, trying out a yellow crookneck that genetic engineers had armed with resistance to two devastating viruses. In doing so, he joined hundreds of other American farmers embarking on what some scientists say is an uncontrolled ecological experiment carrying unknown risks: the planting of millions of acres of genetically engineered crops on American land.
The United States Agriculture Department, the primary agency responsible for assuring the ecological safety of such plants, has not rejected a single application for a genetically engineered crop. Scientists who studied the approvals say the department has frequently relied on unsupported claims and shoddy studies by the seed companies. Department officials defend their decisions but acknowledge that their system for weighing applications is evolving.
Since 1992, dozens of biotechnology crops have been approved for sale to American farmers and hundreds more are in the pipeline, with genes borrowed from every form of life: bacterial, viral, insect, even animal. Farmers like Thiel, seeking greater yields and profits, have enthusiastically adopted the new plants, using biotech seeds for 20 to 45 percent of the country's corn, soybean and cotton last year. Most Americans have probably eaten some food made with genetically modified soy or corn. But Thiel's squash, produced by Asgrow Vegetable Seeds, was the first approved bioengineered crop with the potential to spread its doctored genes into the larger environment.
While fears that such crops are unsafe to eat have raised public alarm in Europe, and to a lesser extent in the United States, some biologists say the more immediate concern is this: that genetically modified plants could interact with the environment in hazardous ways, and that regulators are not demanding the proper studies to assess the risks.
A close look at how the Asgrow squash made its way from laboratory to the dusty fields of West Texas, based on documents and interviews, shows that the virus-resistant strain was approved without rigorous study, setting what critics say is a lax standard for assessing environmental risk.
>From the start, scientists were worried about the possibility that the
squash could breed with wild squash, creating a "superweed" that would
proliferate in the wild or farmers' fields, comparable to relentless
invaders like the kudzu vine of the South and the zebra mussels of the Great
Lakes.
The critical question was whether viruses kept the population of wild squash, which produces inedible gourds, in check. Asgrow determined that they did not, by conducting a survey in which they did laboratory tests on 14 plants from 9 sites. None had the virus.
Experts in environmental risk say the study proved nothing.
"What if we asked if the most important disease controlling human population sizes, malaria, was in fact an important disease?" said Dr. Norman C. Ellstrand, an evolutionary biologist at the University of California at Riverside. "If you took 14 random individuals from around the world, the chances of picking one that has malaria would be relatively low, making the chance of getting a misleading result really high."
Even scientists at Asgrow said that they could have done a more thorough job of providing information to the Agriculture Department on the plant's ecological safety.
"This was a learning process for all of us," said David Tricoli, managing research scientist at Seminis Seeds, which now owns Asgrow Vegetable Seeds. "I'm a molecular biologist. I'm not an ecologist." He said he believed the squash posed no risks.
The Agriculture Department officials involved in approving the squash stand by their decision and note that there are no signs of environmental damage. But the department in effect acknowledged a lack of safety data this summer when another U.S.D.A. agency financed a study to determine whether the genetically engineered squash could create superweeds.
"We feel like we're making the best decisions that can be made on the basis of the information that we have," said Keith Pitts, an adviser to the agriculture secretary. The agency announced Sept. 29 that the National Academy of Sciences would be conducting a review of the agency's regulatory process. Pitts added, "We don't claim to have this system totally worked out."
A growing number of studies suggest that the genetically engineered crops could lead to rapid evolution of pesticide-resistant insects, creation of new plant diseases and harm to insects that benefit mankind. A recent laboratory study, for example, showed that corn pollen engineered to carry a toxin against the European corn borer can kill monarch butterflies.
"Eventually we are going to have some problems," said Dr. Allison A. Snow, a plant ecologist at Ohio State University. "I don't think the risks are being taken seriously or addressed seriously by the system we have now."
Supporters of genetically engineered crops say such fears are overblown and are creating roadblocks for a technology that could feed the world and offer a host of other benefits. For example, Dr. Charles J. Arntzen, president and chief executive of the Boyce Thompson Institute for Plant Research, is developing bananas that grow medicines and could act as child-friendly vaccine delivery systems. Dr. Arntzen compared the risk posed by genetically engineered crops with the risk of getting hit by an asteroid while sitting in his New York office: "The real risk is the hysteria."
The Creation: A Plan to Build the Perfect Squash
For centuries, plant breeders have mated the plants bearing the biggest fruits to produce plants with even bigger fruit, and the hardiest plants to produce hardier ones. But emboldened by the biotechnology revolution, researchers envision giving the world crops that can do much more: fend off pests, thrive in hostile environments and bear fruit offering better nutrition and disease-fighting compounds. Soon, they say, genetically modified plants will serve as biofactories growing plastics and other products; one plant in development would grow cotton with polyester built right into it.
One of the first companies to exploit the new technology was Asgrow Seed Company in Kalamazoo, Mich. In 1986 an Asgrow scientist, Dr. Hector Quemada, teamed up with Dr. Dennis Gonsalves, a biologist at Cornell University, to create a squash resistant to viruses, the bane of farmers. Four years later they were taking genes from two viruses devastating to squash and inserting them into the DNA of normal squash.
The genes produce coat proteins, which encase a virus's genetic material. For reasons not fully understood, coat protein genes provide powerful resistance to the viruses from which they come.
The result was the creation of a squash nearly invulnerable to the two diseases associated with those viruses.
But before Asgrow could begin selling its new squash, it had to get the plant out from under Government supervision. Regulations for genetically modified crops required Asgrow to get federal permission each time the squash was planted in the field and to abide by a number of safety procedures.
If deregulated, the squash could be freely sold or planted anywhere in the United States.
So in 1992, Dr. Quemada and Tricoli petitioned the Agriculture Department, the main government body overseeing genetically modified plants, requesting that the squash be deregulated. (The Environmental Protection Agency regulates plants engineered to produce pesticides; the Food and Drug Administration does not require engineered products to go through an approval process, but is available for consultations.)
In its petition, Asgrow, then part of the Upjohn Company, stated that the plant presented no risk to the environment.
Industry officials and environmental groups watched the case closely. The squash was the second plant to be considered for deregulation, after the Flavr Savr tomato, and the first to raise the possibility of significant ecological threats.
"It was a test case," said Dr. Margaret Mellon, director of the agriculture and biotechnology program at the Union of Concerned Scientists, a watchdog group. "We were all testing the waters."
Scientists were concerned that the squash might turn its relatives into virus-resistant weeds by interbreeding with them. The squash also posed the risk that its virus genes or the coat proteins they produced might interact with other viruses to produce new diseases. And, as with any genetically engineered crop, the squash posed the risk that its new genes might cause it to spread and become difficult to control.
Still, after two months the Agriculture Department issued a proposed ruling approving the squash. Environmental groups and some state agriculture departments protested, prompting the federal agency to commission a report by Dr. Hugh Wilson, a squash expert at Texas A&M University.
But instead of backing up Asgrow and the Agriculture Department, Dr. Wilson agreed with critics. In his report in July 1993, Dr. Wilson found there was insufficient scientific information to draw conclusions about safety and that studies "point toward the clear presence of risk."
Dr. Wilson's report revealed that Asgrow's petition contained crucial errors and omitted information that pointed toward risk. For example, Asgrow claimed that wild squash was unlikely to interbreed with genetically engineered squash, despite much scientific evidence to the contrary. Dr. Wilson's report also noted that the wild relatives of the new squash were already problematic weeds in parts of the country, suggesting it might take little to push them into the category of superweed, another fact omitted by Asgrow.
Despite these findings, in the spring of 1994 the Agriculture Department again proposed approving the new squash and issued draft documents dismissing ecological risks.
The Superweed Threat: Assessing the Risk of a Gourd Gone Wild
The most contentious of Agriculture Department's conclusions in the draft documents was the dismissal of the superweed risk.
The department acknowledged that the new squash would interbreed with wild relatives and pass along its foreign genes. But the virus resistance could only create a superweed problem if viruses were preventing the spread of wild squash in nature. Asgrow had already shown that the wild plants were highly susceptible to viral disease in field experiments. In order to determine how important viruses were in nature, the department in 1993 asked Asgrow to conduct a survey of wild plants.
Researchers did visual scans of an unknown number of plants in nine areas scattered over three states and saw no signs of disease. In addition, they collected 14 plants: one vine from each of eight areas surveyed, and six from a ninth area. Dr. Gonsalves tested the plants for viruses in the laboratory -- the only definitive way to test for viral infection -- and found no signs of disease.
The survey, the Agriculture Department contended, proved that wild populations of the squash were not attacked by viruses. Therefore, the department concluded, the new genes would not be enough to turn wild relatives into superweeds. Therefore, the squash could be deregulated.
But ecologists vigorously objected. They said it was impossible to draw such a conclusion from such a small number of plants over just one summer.
Dr. Peter Kareiva, senior ecologist for cumulative risk assessment at the National Oceanic and Atmospheric Administration, called the study "amazingly small" and noted that if disease was truly a devastating problem, scientists might never find a plant with disease because the virus would have quickly wiped out any plants it encountered.
Even Dr. Gonsalves, a co-creator of the squash, called the survey "preliminary data." Dr. Gonsalves said the Agriculture Department's decision "could be open for criticism. The sample is very small."
But Dr. James White, senior operations manager with the Animal and Plant Health Inspection Service, the Agriculture Department agency that regulates genetically modified crops, defended the approval and the survey.
"There's no evidence that the gourds were ever infected with the virus," Dr. White said, "and there's been no evidence since 1994." He added that there were no known cases in any crop of a new gene resistant to viruses or other anything else making the crop or its wild relatives any weedier.
Despite scathing criticisms of its conclusions, in December 1994, the Agriculture Department again dismissed ecological risks and gave final approval to the squash.
In 1996, a second Asgrow squash with resistance to three viruses was approved by the Agriculture Department. A third Asgrow squash with resistance to all four major viruses is being tested in field experiments.
Since then Dr. Quemada, in a surprising turn, has succeeded in persuading the Agriculture Department to support further analysis of the possible risks of the squash.
After years of arguing on behalf of Asgrow that the squash posed no environmental risk, this summer, Dr. Quemada, now an independent regulatory consultant, received a $253,000 grant from the Agriculture Department to study whether the new squash posed a superweed risk and whether viruses infected wild populations.
Dr. White declined to comment, saying he had not seen the grant. Dr. Quemada said he saw no conflict between his previous work and his receipt of the grant.
The grant was paid for by the Biotechnology Risk Assessment Research Grants Program, a branch of the Agriculture Department independent of the Animal and Plant Health Inspection Service.
The Regulators: A Safeguard, or a Rubber Stamp?
Ecologists say that more worrisome than any threat from the squash is the quality of science and the regulatory process that was used to deregulate the plant, a process meant to be the nation's safeguard against ecological disaster.
In a 1995 study of Agriculture Department petitions, Dr. Joy Bergelson, an ecological geneticist at the University of Chicago, and Dr. Colin B. Purrington, an evolutionary biologist at Swarthmore College, examined the seven petitions approved at that time and reported that much of the data was from critically flawed experiments. They also reported a "remarkable reliance" in the petitions on unsupported claims.
Four years later, Dr. Bergelson said: "It still is the case. A lot of the key experiments don't seem to be being done."
Part of the problem, scientists say, is that the Agriculture Department has set no scientific standards for proving the environmental safety of a plant. Government agencies regulating new products often demand specific experiments and data to establish safety. In contrast, the Agriculture Department asks only that petitioners explain why the new plant is unlikely or likely to pose a number of broadly defined risks.
Most of the tests that companies do use to argue for a crop's safety, researchers say, are inadequate for risk assessment because they are designed specifically to avoid ecological risk. For example, in field trials flowers are often covered to avoid interbreeding with wild plants. In addition, field tests typically run for one or two years, too short a time, ecologists say, to assess a plant's potential weediness.
Dr. Arnold Foudin, assistant director of scientific services at the Animal and Plant Health Inspection Service, defended the regulatory process. The requirements are not vague, he said, but rather are "necessarily generic -- it gives us the flexibility, and the applicant, to supply the necessary information." He added that he believed longer field tests were impractical.
Many scientists, particularly those who genetically engineer plants, applauded the approval of the squash and said environmental risks were overblown. Supporters of genetically engineered plants say critics ask the impossible: technology without risks and a promise of unconditional safety.
"In an ideal world you'd know all the risks and all the benefits before you use something," said Dr. Herb S. Aldwinckle, plant pathologist at Cornell University, "but we'd be very slow to progress if we had to know all that."
Ultimately, risks posed by these crops must be weighed against the benefits they offer farmers, consumers and the environment. But even as the first large-scale studies of benefits of genetically modified plants appear, more questions than answers remain. Even for Asgrow's squash, the plant that Tricoli called "the most highly regulated and reviewed squash product ever produced," the costs and benefits to farmers and the environment remain unclear.
In Idalou, Thiel, who has been planting and picking squash all his life, was philosophical. "We've got a long way to go before we know whether it's good or bad," he said. "The way I see it, whenever you get something, you lose something else. We just don't know what we'll lose yet."
[Sidebar] Studies Note Risks of Genetically Modified Plants
Since genetically engineered crops came on the American agricultural scene in 1992, farmers have enthusiastically adopted these plants, last year harvesting genetically altered corn, soybeans and cotton from 50 million acres -- an area one and a half times the size of New York State. Meanwhile, several studies have been published pointing toward ecological risks from genetically modified plants.
A major concern is that foreign genes from these plants could escape into wild plants by interbreeding. The fear is that wild plants endowed with new genes and potent new abilities, for example, to produce insecticide or withstand herbicide, might spread quickly, becoming difficult or costly to remove.
Previously researchers talked about the movement of foreign genes into wild plants as unlikely, but the picture emerging today is that with many crops it will be inevitable. Recent studies of radishes, grain sorghum, canola and sunflowers found that genes, in one case foreign genes, moved quickly and easily from crops to wild relatives.
Corn, soybeans and cotton pose no such risks in this country, as there are no plants with which they can interbreed. But other genetically engineered crops in development do have wild relatives in the United States with which they can interbreed including rice, beets, canola, sunflowers, cranberries and strawberries.
There have also been a number of recent reports suggesting that the popular crops that produce the insecticidal toxin known as Bt may pose previously unsuspected risks. Bt corn, cotton and potatoes are already on the market but many more Bt crops are in development.
Normally Bt is sprayed on plants to kill pests and is thought to remain active for a matter of days. But in sharp contrast to industry studies, Dr. Guenther Stotzky, soil microbiologist at New York University, has found that Bt toxin in the soil, as it might be found after a crop is plowed under, can remain active for at least eight months.
"We were surprised," Dr. Stotzky said. "I'm sure it hangs around longer. We just terminated the experiment after eight months."
In addition, recent studies of insect genes and insect development suggest that resistance to Bt may evolve more quickly than expected and that current resistance-management schemes for these plants may be ineffective.
Other new studies suggest that Bt crops may have adverse effects on non-pest species. A study published earlier this year showed that, in the laboratory, monarch butterfly caterpillars can be killed by eating Bt corn pollen. Again in contrast to industry studies, Swiss researchers have published evidence that beneficial, predatory insects get sick when they eat Bt or eat pests that have eaten Bt corn.
Ultimately, as with any new technology, risks must be weighed against benefits. So far researchers have found that some crops can provide striking financial and environmental benefits, but only under some conditions.
The Department of Agriculture released a report in July showing that many farmers planting Bt cotton enjoy increased yields and decreased insecticide use, but many also do not.
"Proponents of the technology would like it to be all things to all people," said Ralph Heimlich, deputy director for staff analysis at Economic Research Service, which put out the new study. Opponents prefer to claim it does nothing. The messy truth, however, lies somewhere in between.
"It really is a mixed bag," Heimlich said.
[end]
Carl
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