February 1, 2001 -- The biotechnology debate is full of "hype" on both sides, said Dr. Rebecca Goldburg, senior scientist at the New York headquarters of Environmental Defense (formerly known
as the Environmental Defense Fund). As a result, legitimate, science-based concerns about genetically modified crops receive little attention.Dr. Goldburg works on public policy issues concerning food production for Environmental Defense and has been a member of the U.S. Department of Agriculture's (USDA)
Advisory Committee on Agricultural Biotechnology, the U.S. State Department's US-EU Consultative Forum on Biotechnology, and USDA's National Organic Standards
Board.She recently served on the National Research Council's Committee on Genetically Modified Pest-Protected Crops chaired by Dr. Perry Adkisson, a pioneer in the field of
integrated pest management (IPM) and 1997 World Food Prize Laureate (see AgProfile. She received a
doctorate in ecology and behavioral biology from the University of Minnesota. Dr. Goldburg returned to the Minnesota campus February 1, 2001, to address a conference on
genetically modified crops.
One example of exaggerated claims on the pro-biotech side is statements made about "golden rice," genetically engineered to contain beta-carotene or Vitamin A, according
to Dr. Goldburg. It's often said that "golden rice" will provide a cure for Vitamin A deficiency, a leading cause of blindness and other health problems among children in
developing countries. However, Vitamin A is a fat-soluble vitamin and cannot be absorbed through the human intestinal wall without a certain amount of fat present - and the
people that golden rice is supposed to help often have diets lacking in fat as well as Vitamin A.
"Golden rice, the 'poster child' of biotechnology's benefits to developing countries is not a magic answer to the problem of malnutrition," Dr. Goldburg said.
On the other hand, anti-biotech activists often make much of the risk of antibiotic resistance being passed from genetically modified crops to humans because genes for
antibiotic resistance are frequently used as "marker" genes in the process of inserting new genes into crops. Marker genes are used to identify cells that will accept new DNA.
When antibiotic-resistant genes are used, only cells that accept the new genetic material survive in the presence of the antibiotic.
The gene most often used for this purpose is for resistance to kanamycin, an antibiotic not widely used in human medicine, Dr. Goldburg said. And the potential threat to
human health could be easily eliminated by finding alternative
genetic markers.
Bt corn breezes by regulators. More problematic, from Environmental Defense's point of view, was the process by which Bt corn received approval from the U.S.
Environmental Protection Agency (EPA). An examination of EPA records by Environmental Defense showed no documents evaluating the impact of Bt corn on butterflies and
moths. Along with European corn borer, these species are members of the Lepidoptera family of insects, which is susceptible to the toxin produce by Bt corn. Although
EPA officials assured Environmental Defense that studies on butterflies and moths had been done, there was no evidence that the EPA's assessment of Bt corn was based
on anything but previous studies of sprayable Bacillus thuringiensis products which have been used by organic and conventional farmers for years - and which are not
present in the plant all the time, Dr. Goldburg said.
Federal registration of Bt corn was followed by the widely publicized Cornell University study that showed monarch butterfly caterpillars dying from eating milkweed dusted with
Bt corn pollen. Although the biotech industry has downplayed the potential impact of Bt corn pollen on monarch populations in the field, Dr. Goldburg said subsequent
research has uncovered the following facts:
- Some Bt corn hybrids produce pollen that is more toxic to monarch butterflies than others.
- Although Bt corn pollen is found in concentrations toxic to butterflies near corn fields, milkweed plants - monarch's main food - does grow within corn fields and monarchs
do feed on them there.
Trojan genes in fish. Dr. Goldburg also expressed concern about genetic modification of farm-raised fish. Transfer of genes into fish is easy because fish eggs can
be microinjected with new genetic material. But because farm-raised fish are relatively undomesticated species, the chances of genetically modified specimens escaping to
survive and reproduce in the wild are much more likely.
In fact, conventional farm-raised fish escaping from fish farms are already causing environmental problems, whether tilapia escaping from farms in Florida's Everglades or
Atlantic salmon escaping into Pacific waters.
In November 1999, two Purdue University researchers revealed the possibility of a "Trojan gene effect," Dr. Goldburg said. Female fish prefer to mate with larger male fish. So,
if males genetically engineered to grow faster than conventional fish escaped into the wild, they would have a competitive advantage in mating. However, their offspring might
have less chance of survival, resulting in a threat to the perpetuation of wild fish populations.
AF Protein, a Massachussetts-based company that is developing salmon genetically modified for faster growth, maintains that all of its salmon will be sterile females and that,
in any event, the genetically modified salmon are no larger at sexual maturity than conventional salmon, Dr. Goldburg noted.
The fact remains, however, that "no federal agency has a broad mandate to regulate genetic modification of fish," Dr. Goldburg said. In this vacuum, the U.S. Food and Drug
Administration (FDA) has "stepped up to the plate" and announced it will regulate the introduction of new genetic material into fish as an "animal drug." But Environmental
Defense questions the FDA's expertise in dealing with environmental issues.
"It would be as if the (U.S.) Fish and Wildlife Service announced it was taking charge of food safety issues," Dr. Goldburg said. Even more disturbingly, under U.S. drug law, the
FDA cannot disclose information about products submitted for review unless the company making the submission has already done so.
For AgJournal background on the monarch butterfly controversy, see Goodbye, Bt?.
For more information on AF Protein's transgenic salmon, see Transgenic fish gain as fast as hogs.
For more information on Environmental Defense, see the Environmental Defense Web site.
