RUMINATIONS OF A RADICAL VETERINARIAN
by Michael W Fox, D. VM.
To regard genetically engineered (GE) crops and food as being infected or adulterated
and therefore posing potential risks to human and other consumers (including insects,
birds, and wild and domesticated mammals) and to the environment is not unreasonable
considering the following scientifically documented findings:
- 1. There is evidence that foreign DNA can enter the body via the gastrointestinal
tract and cross the placenta.
- 2. Genetically modified organisms can produce unanticipated toxins or allergens.
- 3. Gene transfer can occur between transgenic plants and bacteria, the ecological
consequences of which could be catastrophic.
- 4. Milk Tom cows injected with rBGH, which is not analogous to normal BGH, has
elevated insulin like growth factor that is implicated as a risk factor in human
- 5. Considering the documented evidence that horizontal gene transfer between
species is a natural phenomenon, the precautionary principle must be applied in creating
transgenic organisms that could transfer novel genes and viral vectors to other species.
The ecological, evolutionary, and public health consequences of such transfers we
will only know after the fact. Horizontal gene transfer is even likely to take place
in the digestive systems of protozoa, nematodes, insect larvae, and other soil macroorganisms.
- 6. That genes, like viruses, can infect the body, should serve as a warning to
us all of the potential risks of transgenic organisms serving as a reservoir for
new diseases, and as a medium for the evolution of new pathogens because of their
altered physiology and biochemistry. Viral "promoters" and "enhancers"
that boost expression of transgenes could result in the production of high levels
of Bt toxin and other chemicals in transgenic crops.
- 7. Unanticipated multiple side effects of gene insertion (called pleotropic effects)
have been well documented. Genetic alterations in crops like soybeans to make them
resistant to herbicides may result in unpredictable, unnatural genetic recombinations
and change the biochemistry and nutritive value. Higher levels of phyto estrogens
are produced in beans grown in the presence of the herbicide glyphosate which may
be of particular risk to children.
- 8. Some 99 percent of commercial transgenic crops incorporate virus genes, either
as promoters or to control virus infections. These virus genes can recombine with
other viruses and may result in new diseases and more invasive pathogens. With the
inclusion of antibiotic resistance markers, transgenic crops could therefore increase
the probability of new viral and bacterial pathogens and the spread of antibiotic
and drug resistance genes. DNA released from living and dead cells can persist in
the environment and be transferred to other organisms. An organism may be dead, but
its "naked" DNA released from decaying cells may remain biologically active
for potentially thousands of years, especially in certain soils and marine sediments.
Naked DNA (nucleic acids) ingested by mice can be transferred to offspring and be
voided and spread in the feces of animals.
- 9. The instability of transgenic crops is a major concern. "nere is, in
fact, no data documenting the stability of any transgenic line in gene expression,
or in structure and location of the insert in the genome. Such data must include
the level of gene expression, as well as a genetic map and DNA base sequence of the
insert and its site of insertion in the host genome in each successive generation.
No such information has ever been provided by industry, nor requested by regulatory
authorities" (Mae Wan Ho, "Dangerous Liason Deadly Gamble in Agricultural
Biotechnology and Environmental Quality: Gene Escape and Pest Resistance" Biotechnology
Council Report #10, ;999).
- 10. One must consider not only the "fate" of transgenic organisms but
also the genes and viruses or parts thereof that have been inserted into them. Such
"naked DNA," in the form of recombinant and ;;odified nucleic acids, has
been found capable of surviving and remaining functional longer after death than
was assumed previously. Furthermore, xenobiotics, especially dioxins and various
agrichemicals, can act as mutagens, altering the structure and sequence of DNA and
also increasing the permeability of cells and the incorporation of foreign DNA into
Contan driation of the "life stream" by naked recombinant DNA, by transgenic
viral vectors and antibiotic resistant genes, is already taking place. Since a recall
is impossible, our best hope, if it is not already too late, to control genetic pollution,
is a five year worldwide moratorium on the creation and release of all genetically
engineered living entities and products, from new vaccines to transgenic crops, so
that science based risk assessments can be properly completed.
Michael W Fox is senior scholar, bioethics, The Humane Society of the United States,
2100 L Street ATW, Washington, D.C. 20037.
Dr Fox's latest book, Eating With Conscience: The Bioethics of Food, is available
frvm Acres U.S.A. for $15. 00, plus $1.50 shiipping and handling, $3.00 international
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