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BIOTECH--THE BASICS, FINAL PART
Biotechnology corporations want people in the U.S. and around the world to believe that the U.S. government has fully tested genetically engineered crops for ecological and human health hazards. Three federal agencies -- U.S. Food and Drug Administration (FDA), U.S. Department of Agriculture (USDA), and U.S. Environmental Protection Agency (EPA) -- have responsibility for genetically engineered foods, but there is no guarantee that a genetically engineered food sold in the U.S. has been tested for ecological or human health effects. In the rush to promote genetic engineering, safety testing has fallen through the cracks.
Biotechnology corporations also want us to believe that genetically engineered foods have been embraced by the public. In fact, genetically engineered foods are not labeled, so the public has no knowledge -- and no choice -- about purchasing and eating them.
U.S. Food and Drug Administration
The U.S. Food and Drug Administration (FDA) issued its basic policy statement on genetically engineered foods in 1992. Under this policy, FDA considers genetically engineered foods to be "generally recognized as safe" (GRAS), unless in the judgment of the manufacturer there is some reason for concern.[2, pg. 22990] Foods considered GRAS are not subject to pre-market safety testing.
FDA states that the need for safety testing depends on the characteristics of a food, not on the methods used to produce it. In other words, the fact that a food was produced using genetic engineering is not sufficient to trigger safety tests.
FDA's 1992 policy says that a genetically engineered food must be labeled if it "differs from its traditional counterpart such that the common or usual name no longer applies to the new food, or if a safety or usage issue exists to which consumers must be alerted." For example, it says a tomato containing peanut genes might need to be labeled so that people with peanut allergies could avoid it. But FDA allows biotechnology corporations to decide whether a hazard of this sort exists. Under FDA's no-labels policy, we can find out the fat, cholesterol, sodium, potassium, carbohydrate, and protein content of our breakfast cereal but we can't find out whether it contains antibiotic-resistance genes, viral promoters, or proteins normally produced only by bacteria.
In 1998 a coalition of non-governmental organizations, scientists, and others filed a lawsuit against FDA for failing to fulfill its regulatory duties. During the suit, FDA was forced to release internal documents that showed FDA staff scientists had strongly opposed the 1992 policy.
The lawsuit also forced FDA to release details of its safety evaluation of the first genetically engineered food that entered U.S. supermarkets, the Flavr Savr tomato. Calgene, the company that developed the Flavr Savr, submitted three safety tests to FDA in which rats were fed engineered tomatoes. After twenty-eight days of the Flavr Savr tomato diet, researchers examined the rats' stomachs. The three studies produced inconsistent results that Calgene was unable to explain. The first study showed no unusual effects. In the second study, some of the rats fed genetically engineered tomatoes developed gastric erosions (damage to the lining of the stomach). In the third study, gastric erosions appeared in some of the rats fed genetically engineered tomatoes AND in some of the rats fed ordinary tomatoes.
Calgene concluded these stomach problems were unrelated to eating genetically engineered tomatoes, but it had no explanation for why they appeared. An FDA staff scientist who reviewed Calgene's data said there were "doubts as to the validity of any scientific conclusion(s) which may be drawn from the studies' findings," because Calgene could not explain the variations in results among the three tests.[4] In spite of the doubts expressed by its own staff, FDA categorized the Flavr Savr tomato as GRAS and approved it for sale. (The Flavr Savr did not sell well, so it has disappeared from stores.)
In January 2001, the FDA proposed new regulations on genetically engineered food. These proposed regulations still fail to require either pre-market safety testing or labeling of genetically engineered foods.[5] FDA says "there does not appear to be any new scientific information that raises questions about the safety of bioengineered food currently being marketed," and states once again that genetically engineered foods are "generally recognized as safe."
To make this claim, FDA had to ignore scientific information that had been brought to its attention explicitly during the previous year. In March 2000, the Center for Food Safety and partner organizations filed a legal petition asking FDA to start requiring pre-market safety testing, environmental impact assessments, and labeling for all genetically engineered foods. The petition included a thorough review of new scientific evidence on safety concerns associated with genetic engineering.
The main new requirement in FDA's proposed regulations is that producers of genetically engineered foods must notify FDA 120 days before bringing a new genetically engineered food to market. This notification, known as a pre-market biotechnology notice (PBN), would include various information, such as whether the product contains antibiotic-resistance marker genes and whether it is likely to produce allergic reactions. FDA says it will make a list of PBNs available to the public, but the list may not be complete. In some cases, FDA says, the existence of a PBN could be considered "confidential commercial information." As a result, under the proposed regulations a company could market a genetically engineered food without any public notification. FDA's proposed regulations are open for public comment until April 3, 2001.
FDA has also proposed to create non-binding guidance for voluntary labeling. This guidance is clearly not intended for companies using genetically engineered crops, which have nothing to gain by telling consumers what is in their food. Instead, the guidance undermines consumers' right to know what they are buying and threatens to limit the free speech of organic and other food producers, by discouraging the use of labels with phrases such as "biotech free" or "no genetically engineered materials." FDA says these labels will be misleading on most foods, because ordinary food could be contaminated with the products of genetic engineering. In addition, FDA says these phrases could imply that non-engineered food is superior to engineered food, which, FDA says, would be misleading.
U.S. Department of Agriculture
Under the Federal Plant Pest Act, the U.S. Department of Agriculture (USDA) is responsible for regulating "plant pests" -- organisms that could cause harm to a plant. USDA considers genetically engineered plants to be possible plant pests if they contain genetic material from organisms, such as some bacteria, included on an official list of plant pests.[1, pg. 109] Plants engineered without the use of genes from a recognized plant pest may escape USDA regulation entirely. Even when genes from a plant pest are involved, the manufacturer has discretion to decide whether the engineered plant is itself a plant pest. USDA does not tell manufacturers what data to take into account when they make this decision.
Under USDA's rules, genetically engineered crops that are considered plant pests must first be approved for field testing before they are approved for commercial planting. After conducting field tests, the developer of a genetically engineered crop can apply for "nonregulated status," under which the crop can be planted commercially with no further oversight from USDA. USDA leaves it up to the developer to decide what data to submit in support of its application for nonregulated status.[1, pg. 111] According to a recent article in AMERICAN SCIENTIST, many tests that companies submit to USDA are poorly designed, so they are unlikely to reveal any adverse effects that may occur.
U.S. Environmental Protection Agency
As we saw in REHN #716, crops can be engineered to kill certain insects by adding a gene derived from the bacterium BACILLUS THURINGIENSIS (Bt). Under its authority to regulate pesticides, the U.S. Environmental Protection Agency (EPA) is responsible for evaluating the health and environmental consequences of these engineered plants, which are, themselves, pesticidal.
EPA has registered pesticidal crops for five years, but the agency makes these registration decisions on a case-by-case basis; it does not have a standard testing system tailored to the hazards posed by genetically engineered crops.[1, pg. 176] EPA says it is reviewing existing registrations for Bt corn and cotton this year, in order to decide whether it is safe to continue growing them.
When EPA registers a chemical pesticide for use on food crops, it establishes a tolerance level -- an amount of pesticide residue that is allowable on food. However, thus far EPA has exempted all pesticidal crops from this requirement.
Pesticidal crops are likely to promote the development of Bt- resistant pest populations. Despite ample scientific knowledge about this danger, EPA waited until December 1999 to issue requirements for resistance management. Under these requirements, companies selling Bt corn are responsible for making sure that farmers grow "refuges" of ordinary corn alongside their pesticidal crops. The idea is that some pest insects will eat only the ordinary corn, so they will be sheltered from the evolutionary pressure that promotes the development of resistant pest populations.
In the past five years, corporations have introduced a powerful new technology into our food system without understanding the basics of how this technology works. Government agencies have refused to gather crucial data on how this technology can affect ecosystems and human health. Once again, we are flying blind.
BIOTECH: THE BASICS, PART 3
As we saw in REHN #716, genetically engineered crops now planted in the U.S. and worldwide are mostly designed to tolerate herbicides or to kill insects or other pests. A small percentage is designed for other purposes such as resisting infection by certain viruses. Here we will look at some of the threats genetically engineered crops pose to ecosystems.
Pesticidal crops may be toxic to nontarget organisms - organisms they were not designed to kill. For example, BT corn designed to kill the European corn borer can also be toxic to other closely related insects, including butterflies and moths.
Monarch butterfly larvae feed on milkweed, which often grows in or near corn fields. In a laboratory, scientists found that monarch larvae feeding on milkweed dusted with BT corn pollen grew more slowly and died at a higher rate than larvae that were not exposed to the toxic pollen.[1] Another study found these effects were likely to occur outside the laboratory as well. Researchers placed potted milkweed plants in fields of BT corn and measured the number of BT pollen grains that were deposited on the milkweed leaves. Monarch larvae exposed to BT corn pollen at these levels had high death rates compared with larvae exposed to non-engineered corn pollen or placed on milkweed leaves with no pollen.
The U.S. Environmental Protection Agency (EPA) now expresses concern about the effects of BT corn pollen on monarchs and other butterfly species, including the endangered Karner Blue butterfly.[3] EPA has asked companies to submit data on these effects, but this "data call-in" occurred four years AFTER EPA allowed BT corn to be used on U.S. farms.
BT corn may also harm the green lacewing, a beneficial insect that eats agricultural pests. The lacewing may be affected by the toxin in the digestive systems of insects that have eaten BT corn but have not been killed by it.[4] This example shows how non-target effects may interfere with a chain of predator-prey relationships, disrupting the natural balance that keeps pest populations under control.
BT crops may also affect non-target organisms by changing soil chemistry. A 1999 article in NATURE reported that the roots of BT corn plants released BT toxin into soil. The researchers found that 90 to 95% of susceptible insect larvae exposed to the substance released from the roots died after 5 days.
The use of BT crops can also promote the development of BT-resistant pest populations. As we saw in REHN #716, organic farmers use BT sprays occasionally as a natural insecticide to combat severe pest outbreaks. BT crops, in contrast, generally expose insects to BT toxins day after day, whether or not there is a major infestation. These conditions increase the likelihood that BT-resistant insects will evolve. The widespread appearance of BT-resistant insect pests would mean the loss of one of the most valuable tools available to organic farmers for dealing with serious pest outbreaks.
Herbicide-tolerant crops are designed to make it easier for farmers to use certain herbicides. A 1999 study of soybean farming in the U.S. midwest found that farmers planting Roundup Ready soybeans used 2 to 5 times as many pounds of herbicide per acre as farmers using conventional systems, and ten times as much herbicide as farmers using Integrated Weed Management systems, which are intended to reduce the need for chemical herbicides.[7,pg.2] Glyphosate, the active ingredient in Roundup, can sometimes persist in soil over long periods of time[8] and may affect the growth of beneficial soil bacteria, among other environmental effects.[9] A recent, unpublished study conducted at the University of Missouri suggests that applications of Roundup to Roundup Ready crops may be associated with elevated levels of soil fungi that sometimes cause plant diseases.
More hazards may lie ahead as new products of genetic engineering come to market. According to the NEW YORK TIMES, Scotts Company is collaborating with Monsanto to develop Roundup Ready grass for lawns.[11] Studies suggest that Roundup exposures can be harmful to human health. For example, exposure to glyphosate herbicides may be associated with increased occurrence of non-Hodgkins lymphoma, a cancer of white blood cells. And a study published last August in ENVIRONMENTAL HEALTH PERSPECTIVES found that in a laboratory, Roundup exposure interfered with sex hormone production in cells of testicular tumors taken from mice.[13] If the introduction of Roundup Ready grass leads to increased use of Roundup on lawns, children's exposure to the herbicide could rise.
In some cases, genetically engineered crops might become problem weeds, disrupting existing ecosystems. A recent study published in NATURE found that some genetically engineered crops are unlikely to become problem weeds. Researchers planted genetically engineered crops that were available in 1990 and monitored their growth for ten years. Many of the plants simply died out, and those that did survive showed no signs of spreading.[14] But some crop plants, such as canola, survive well on their own without human intervention. In Canada, genetically engineered canola plants designed to resist various herbicides appear to have exchanged genetic material so that some canola plants now can survive exposure to two or three herbicides. These plants with multiple herbicide resistance can be difficult for farmers to control.
Genetically engineered virus-resistant crops are supposed to reduce problems from viral infections, but in some cases they could make those problems worse. Virus-resistant crops are created by adding virus genes to the plant's existing genetic material. If a genetically engineered crop resistant to one virus is infected by another virus, the genetic material from the two viruses may sometimes interact to produce new virus types, which could be more harmful or could infect a wider range of plants than the original.
All the hazards discussed above are compounded by the problem of genetic pollution. Many crop plants disperse genetic material through pollen, which may be carried by the wind or by pollinators such as bees. This means genetically engineered plants may "share" their genetic material with other, non-engineered plants. For example, pollen from genetically engineered corn can blow into a neighboring field and pollinate conventional corn. Because of genetic pollution, some organic farmers whose fields border genetically engineered crops may no longer be able to certify their crops as organic.
In animals, sexual reproduction between different species is usually impossible. In a few cases, reproduction between closely related species can occur but the offspring are generally sterile. For example, a horse and a donkey can mate to produce a mule, but mules cannot reproduce. In contrast, many plants are able to reproduce sexually with related species, and the offspring of these combinations are often fertile. When crop plants grow near wild plants to which they are related, they may reproduce with these plants. This means that genetic material inserted into a crop plant can find its way into wild plant populations.
A recent article in SCIENCE reviews the literature on "ecological risks and benefits" of genetically engineered crops and confirms what advocates of precaution have been saying for years: we lack basic information on how genetically engineered crops may affect ecosystems.[16] Here are a few examples of what scientists do not know about ecological effects of genetically engineered crops:
** No published studies have looked at whether novel genes introduced into crops have become established in populations of wild relatives.
** We know that BT toxin can be released from the roots of BT corn plants, but no published studies have looked at the ecological consequences of adding BT toxin to soil in this way.
** As we have seen, BT toxin in the digestive systems of plant-eating insects may affect the predator insects that eat them. Right now it is impossible to model how an ecosystem might change due to these effects on predators, the authors say
** Scientists are currently unable to estimate the likelihood that planting genetically engineered virus-resistant crops will lead to the development of new types of plant viruses.
A precautionary approach would require that we investigate these questions before, rather than after, permitting large-scale commercial cultivation of genetically engineered crops.
BY: Rachel Massey a consultant to Environmental Research Foundation.
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