The corporations that are introducing genetically modified crops into the global ecosystem want you to think of genetic engineering as a well-understood science similar to laparascopic surgery. Indeed, the phrase "genetic engineering" gives the impression that moving genes from one organism to another is as straightforward as designing a rocket or a TV set. This is not the case.
Basically, a plant's genome (all of its genes, taken together) is a black box. Genetic engineering takes a gene from one black box and forces it into a second (the recipient plant), hoping that the new gene will "take". Once in a few thousand tries, the foreign gene embeds itself in the recipient plant's genome, and the newly modified plant gains the desired trait.
That is all the technicians know. They have no idea where in the receiving plant's genome the new gene has found a home. This fundamental ignorance, combined with the speed and scale at which modified organisms are being released, raises a host of questions of safety for agriculture, for the environment and for human health.
- A gene may control several different traits in a plant. Without careful study, plants with undesirable characteristics may be released into the global ecosystem. And biotechnology is not like a chemical spill that can be mopped up — once you release a new gene sequence into nature, there's no taking it back.
- The same gene can have different effects, depending on the environment in which the new plant is growing. What appears predictable and safe after a few years in a small test plot may turn out to have quite different consequences when introduced into millions of acres of crop lands where conditions vary widely.
- Does the new gene destabilise the entire plant genome in some unforeseen way, leading one day to problems in that crop? Only time will tell.
- Genes can travel to nearby related plants on their own. This is called gene flow. In 1996 gene flow was discovered to be much more common that previously thought.
According to Science magazine, many ecologists say it is only a matter of time before an engineered gene makes the leap to a weedy species, thus creating a new weed or invigorating an old one.
"It will probably happen in far less than 1% of the products", warns ecological geneticist Norm Ellstrand of the University of California at Riverside, "but within 10 years we will have a moderate-to-large scale ecological or economic catastrophe, because there will be so many [genetically modified] products being released".
The Congressional Office of Technology Assessment recommended that all genetically modified plants should be considered non-indigenous exotic species, with the power to disrupt ecosystems.
- A public health disaster was narrowly averted in 1996 when a group of researchers tried to give soybeans a gene from the Brazil nut. The goal was to improve the nutritional value of soybeans by forcing them to produce more methionine, an essential amino acid.
After the gene from the Brazil nut had been transferred to soybeans, but before the soybeans were sold commercially, independent researchers tested the soybeans to see if they would cause allergic reactions in people. Many people are allergic to Brazil nuts. In some people, the reaction to Brazil nuts is swift and fatal.
Laboratory tests confirmed that the genetically modified soybeans did provoke Brazil-nut allergy in humans. In discussing their findings in the New England Journal of Medicine, the researchers pointed out that tests on laboratory animals will not necessarily discover allergic reactions to genetically modified organisms. Only tests on humans will suffice.
US Food and Drug Administration (FDA) requires testing for allergic reactions only if a gene is being taken from a source that is already known to cause allergic reactions in humans. Many genes are being taken now from bacteria and other life-forms whose allergenicity is entirely unknown, so federal regulations require no allergy testing.
- Crops are being genetically modified chiefly as a way to sell more pesticides. In some cases, the modified crops change the pesticides themselves, giving them new toxicity. The herbicide bromoxynil falls into this category.
Bromoxynil is recognised by the US EPA (Environmental Protection Agency) as a possible carcinogen and as a teratogen (causing birth defects). Calgene (now owned by Monsanto) developed a strain of cotton plants (called BXN cotton) that can withstand direct spraying with bromoxynil. Unfortunately, the bromoxynil-resistant gene modifies the bromoxynil, turning it into a chemical by-product called DBHA, which is at least as toxic as bromoxynil itself.
Although humans do not eat cotton, traditional silage for cattle contains up to 50% cotton slash, gin mill leavings and cotton debris. Both bromoxynil and DBHA can accumulate in the fat of animals. Therefore, it is likely that DBHA will make its way into the human food chain through meat.
Furthermore, cottonseed oil is widely used as a human food and as a cooking additive. In licensing bromoxynil for use on Monsanto's genetically modified BXN cotton, EPA conducted a risk assessment that assumed bromoxynil and DBHA had no way to enter the human food chain.
Thus genetic engineering — which is being promoted as a technology that will reduce the perils of pesticides — will in some instances increase them.
In rats and in rabbits, bromoxynil causes serious birth defects, including changes in the bones of the spine and skull, and hydrocephaly. These defects appear in offspring at doses that are not toxic to the mother. Despite these findings, EPA in 1997 declined to require a special safety factor to protect children from bromoxynil.
Lastly, when EPA added up the cancer-causing potential of bromoxynil, it found it to be 2.7 per million, and promptly declared this to be "well within" the one-in-a-million regulatory limit!
- Because genetically engineered soybeans will be doused with increased quantities of herbicides, soybeans and soy products will carry increased chemical residues. Infants who must be raised on soy milk, because they cannot tolerate lactose in regular milk, will be at special hazard.
- Crops that are genetically modified to resist herbicides detoxify the herbicides by producing proteins, which will be incorporated into our food with unknown results.
- The "life sciences" companies have big plans for turning agricultural crops into "factories" for producing pharmaceuticals and specialty chemicals. They plan to manufacture vaccines, drugs, detergents, enzymes and other chemicals by putting the right genes into the right plants.
The net effect will be to expose soil insects and micro-organisms, foraging and burrowing animals, seed-eating birds and a myriad of other non-target organisms to these chemicals and to the gene products that make them. The Union of Concerned Scientists says, "Herbivores will consume the chemicals as they feed on plants. Soil microbes, insects, and worms will be exposed as they degrade plant debris. Aquatic organisms will confront the drugs and chemicals washed into streams, lakes, and rivers from fields."
- Genetically engineered crops substitute human wisdom for nature. As genetically engineered crops are planted on tens of millions of hectares, the diversity of agricultural systems is being further diminished. Do we know enough to select the "right" combination of genes to assure the stable, long-term yield of our agricultural systems?
Experiences with PCBs, CFCs, DDT, Agent Orange and global warming should give us pause. Genetic engineering is by far the most powerful technology humans have ever discovered, and it is being deployed by the same corporations that, historically, have produced one large-scale calamity after another. Is there any good reason to think things will be different this time?
[From Rachel's Environment & Health Weekly. Like Green Left Weekly, Rachel's is a non-profit publication which distributes information without charge on the internet and depends on the generosity of readers to survive. If you are able to help keep this valuable resource in existence, send your contribution to Environmental Research Foundation, PO Box 5036, Annapolis, Maryland 21403-7036, USA. In the United States, donations to ERF are tax deductible.]