Make your own free website on Tripod.com
ngin - Norfolk Genetic Information Network

7 July 2002

DRUG GENES COULD ENTER FOOD CHAIN - NEW SCIENTIST/PURDUE UNIVERSITY

The New Scientist piece below (item 1) points to the inadequacy of planned safeguards for the growing of powerful pharmaceuticals in food plants. As the Purdue University fact sheet (item 2) makes clear, this is not a food safety issue of the future. Open air production of pharmaceutically related products in corn is already underway on hundreds of acres in the US's western Corn Belt, including Iowa, one of the states worst affected by the Starlink debacle. In that case a corn not approved for human consumption, which was being grown on relatively few acres, caused widescale contamination of the food chain. As ABC NEWS reported at the time, "In Iowa, StarLink corn represented 1 percent of the total crop, only 1 percent. It has tainted 50 percent of the harvest." (ABC NEWS, November 28, 2000)
 
1. Drug genes could enter food chain
2. CONCERNS OVER PHARMACEUTICAL TRAITS IN GRAINS AND OILSEEDS

***

1. Drug genes could enter food chain

BY Philip Cohen; San Francisco
New Scientist, July 6, 2002

Loopholes in US regulations raise fears that food crops will be contaminated with pharmaceuticals

THE rules the US government is proposing for field tests of crops that have been genetically modified to produce pharmaceutical products are not strict enough to prevent the contamination of food crops, experts have told New Scientist.

They say the proposed rules are based on flawed science, that there are loopholes allowing them to be bypassed, and that companies do not even have to disclose what genes have been added. And they warn of severe environmental consequences if a drug-laced plant were to breed with other crops or wild relatives.

Biotech companies plan to produce a vast range of products, from drugs to vaccines, in plants. "These plants have the potential for more benefit than any other agribiotech product," says Jane Rissler of the Union of Concerned Scientists in Washington DC. "But to realise those benefits we have to be very careful about the risks." The US Department of Agriculture's (USDA) plans don't come close, she says. What scares Rissler and others is that there could be a rerun of the Starlink debacle, in which GM corn strictly not intended for human consumption ended up on grocery shelves. If any contamination involved a crop producing a potent drug, the consequences could be far more serious, she says.

The proposed rules require the "pharmed" plants to be separated from other crops in time as well as space. For example, pharmed maize must be grown at least 400 metres away from other maize. It must also be planted two weeks before or after nearby crops, so that it isn't fertile at the same time. Similar regulations have been outlined for other plants that have been engineered to make drugs, including barley, corn, rice and sugar cane. But when it comes to keeping harvested products separate, the rules are vague, talking only of "adequate identification, packaging and segregation".

Companies that violate these procedures can be fined dollars 250,000, and individuals could face jail sentences of up to five years. James White, the USDA's branch chief for biotech evaluations, is confident the rules will do their job:"The chance of gene flow is essentially zero."

"These rules are more stringent than prior recommendations, and I applaud that," says Norman Ellstrand of the University of California, Riverside, who sat on a National Academy of Sciences committee that reviewed the regulations for GM crops. "But there are big holes in the system."

The NAS report points out that some of the USDA's rules have no clear scientific rationale. For instance, the isolation distance for corn is simply double the 200 metres it recommends for the production of GM seeds. The assumption is that this spacing will reduce contamination to 0.1 per cent, but there is no evidence that the contamination risk drops off with this increase in distance. Only last week, Australian researchers reported that pollen from oilseed rape had contaminated fields up to 3 kilometres away, and that there was no obvious drop-off with distance (Science, vol 296, p 2386).

Another serious concern is that the USDA focuses on the intended use of a crop product and ignores its other possible impacts. For instance, the Texas-based company Prodigene applied to grow maize that produces a chicken-egg protein called avidin, which is known to kill or harm 26 species of insects. But because avidin is not classed as a drug, the crop doesn't come under the pharming regulations. Nor did the USDA look at the maize's environmental impact because the crop wasn't being grown in order to kill insects. "If they had used the same protein as an insecticide, they would have called in the Environmental Protection Agency to regulate it," says Ellstrand.

While avidin's properties are well known, that is not the case with every drug that might end up being grown in crops. Ellstrand and his colleagues were disturbed to discover that the publicly available descriptions of genes spliced into some plants are incredibly vague.

White says the USDA will start posting fact sheets on genes in transgenic plants later this month. When a company wants to keep the identity of a gene secret, it will give it a code name and a general description, such as "Gene S is a hormone in humans. It is harmless to invertebrates," and so on.

He also says the only drugs so far being grown in crops are proteins that would simply be digested if accidentally eaten by humans or animals. "The risks are minimal," White says. "No one is making Viagra in a field." But there's nothing to stop companies producing a Viagra crop if they want to. "It's a disaster waiting to happen," says Doreen Stabinsky, a science adviser for Greenpeace. "Grow this stuff in a greenhouse or a cave, not in an open field where animals can grab the seeds."

Ellstrand agrees that stricter containment is needed. Pharmed plants could be genetically engineered to prevent gene flow using methods such as the infamous Terminator technique, which makes seeds sterile, or a newly proposed one dubbed the Exorcist (see "Begone! evil genes"). And to be absolutely certain the food supply is safe, he argues that only plants that aren't grown for food should be used to make drugs.

White points out that when the long-awaited regulations are finally published, the public will have 120 days to respond. "I wouldn't be surprised if we got thousands of letters telling us: not in food."

***

2. Concerns over Pharmaceutical Traits in Grains and Oilseeds Grain

Quality Task Force
Purdue University
Fact Sheet #47 * July 2, 2002

Dirk E. Maier, Agricultural & Biological Engineering
The complete document is available at:
http://www.agcom.purdue.edu/AgCom/Pubs/GQ/GQ-47.pdf

An April 10 Reuters press release (www.reuters.com) indicates that a biotechnology company, ProdiGene ® , College Station, TX (www.prodigene.com), through a grant from the National Institutes of Health (NIH), has produced a transgenic corn variety that contains a protein found on the surface of HIV, the virus that causes AIDS.  The company's intent is to utilize such corn in the future as an oral delivery system for an AIDS vaccine, through corn-based products such as breakfast cereals. This transgenic corn variety apparently has been grown on enough acres already to produce sufficient quantities of grain to begin animal studies during the summer of 2002, to determine whether ingestion of this corn elicits an immune response.

Five other transgenic corn hybrids from Prodigene ® have been released commercially via Stauffer Seeds ® , Omaha, NE (www.StaufferSeeds .com), and have been grown by a select group of farmers on a few hundred acres primarily in the western Corn Belt, much of it in western Iowa and on irrigated acres in Nebraska. These hybrids contain:
Aprotinin - a protease inhibitor that is used in medical applications to control blood loss during surgery and in non-medical applications as a cellculture reagent.
Avidin - a protein that binds with biotin to make useful products for the medical and biochemical diagnostics industry and has application in protein purification.
Laccase - an industrial enzyme used for adhesives in the manufacturing of medium density fiberboard (MDF) as well as in the detergent industry as an environmentally friendly bio-bleach
Brazzein - a low calorie, intense natural sweetener 2000 times sweeter than sucrose.
Trypsin - a protease enzyme that has many uses including as an intermediate in pharmaceutical manufacturing and in the leather tanning and detergent industries.

Additional protein-based drugs and industrial compounds produced from genetically modified (GM) field crops are currently under development by several companies and are expected to be ready for commercial release approval within a few years.

Examples include:

A topically-applied antibody from Epicyte Pharmaceutical Inc., San Diego, CA (www.epicyte .com), that prevents the transmission of herpes simplex virus (HSV) 1 and 2, topical contraceptive microbicides and preventives for pulmonary infection due to Respiratory Syncytial Virus (RSV) and Clostridium difficile-associated diarrhea.

Antibodies for therapeutic blood products from Monsanto1s Integrated Protein Technologies, St.  Louis, MO (www.iptbio.com).

Prodigene's oral vaccine products including hepatitis-B vaccine, Lt-B vaccine to treat E. coli in humans, TGEV vaccine to treat the transmissible gastroenteritis virus that kills thousands of piglets every year, and additional confidential animal vaccines and human health products under development with such partners as Eli Lilly and Avant Immunotherapeutics.

Various seed companies that are partnering with biotechnology firms are already recruiting farmers, and in some instances crop acres have been acquired by foreign biotechnolgy companies such as Meristem Therapeutics Inc., Clermont-Ferrand, France (www.meristem-therapeutics.com), for experimental testing on private farmland throughout the midwestern Corn Belt.

[EXCERPTS FROM THE REST OF THE FACT SHEET]

Contamination Concern

...the fact that transgenic grains and oilseeds for use as pharmaceutical drug carriers and industrial chemicals may be making their way into a field near your farm, grain elevator, feed mill or processing plant should be a concern, especially in light of the grain industry‚s most recent contamination experiences with Aventis‚ StarLink· corn, which contains a protein approved for feed but not food consumption, and Monstanto‚s GT200- containing canola seed, which contains a protein not approved for any end use. Both of these crops were grown on relatively few acres, yet containment protocols to channel or identity-preserve (IP) them at the seed plant, on the farm, and/or at the elevator failed to prevent trace amounts above detectable limits in commercial feed and food bulk grain samples taken from domestic and export market channels. Experience and science-based research tell us that no identity preservation system will ever be able to contain 100% of every seed kernel, plant pollen and grain kernel generated from crops grown in agricultural fields. The very definition of a quality-management- system approach to segregated and traceable production, harvesting, handling and transport of IP grains and oilseeds is based on defining, meeting and monitoring statistically-based threshold limits that are reasonable and practically achievable with respect to containment, purity and contamination.

Concern over Lack of Federally Regulated Tolerance Levels

Successful identity preservation has been the backbone of the seed industry for years. Most of us would consider seed producers among the most educated, dedicated and best equipped with respect to maintaining the identity of a crop and preventing that crop from contaminating or being contaminated by another crop during planting, growing, harvesting, post-harvest handling and transporting.

Yet the seed industry cannot achieve 100% pure IP seed during production, handling, cleaning and bagging. Instead, a contamination level of 1% is the strictest limit the industry states can be achieved reasonably and practically, with respect to seed purity (www.amseed.com/intl_network.asp ). The principle challenge for IP systems is that whenever new genetic material is introduced into the agricultural crop mix, trace contamination of non-target crops is unavoidable. This fact is common knowledge in the seed industry. Trace amounts, above detectable limits, of a newly commercialized genetic event are often detected whenever stored seed samples of three- to five-year old pre-commercialization varieties are tested, following the release of a new test kit. Thus, if containment of undesired or unapproved genetic events is not 100% effective, for the purpose of seed purity, it will also not be effective for the purpose of crop purity, especially as more GM traits for pharmaceutical and industrial compounds in grains and oilseeds are commercialized.

Therefore, federally-regulated tolerance levels based on detectable thresholds similar to the Environmental Protection Agency‚s (EPA) pesticide residue limits and the Food and Drug Administrations‚ (FDA) mycotoxin limits are urgently needed to define the allowable residue limits of pharmaceutical and industrial compounds in grains and oilseeds for food and feed use. Additionally, availability of reliable and inexpensive testing technology such as strip test kits for grain elevator use must become mandatory with the commercial release of every new genetic event in order to give the U.S. grain production, handling, exporting and processing industry the competitive advantage to meet customer demands with respect to the presence of approved but undesired GM-crop traits below established tolerance levels.

...It cannot be assumed that trace contamination of non-target crops is avoidable and the possibility cannot be ignored that an active ingredient could be expressed so highly concentrated that a single kernel might exceed food safe exposure limits. Therefore, the major world food and feed staple crops should not be used for transgenic modifications for the purpose of expressing pharmaceutical ingredients and industrial chemicals, unless they can meet food safety requirements.

If the federal government does not intervene with threshold limits and stricter regulation and oversight soon, it will be just a matter of time before trace amounts of unapproved and non-food/feed-safe pharmaceutical and industrial proteins will be detected in our domestic and export food and feed market channels.

This potential scenario will likely cause a far greater public outcry than did the StarLink discovery in taco shells. The future use of the world's major food and feed staple crops for the development of edible vaccines and other protein-based drugs and industrial chemicals on a few thousand acres far outweigh the risk of jeopardizing the United States‚ domestic and export markets due to contamination of grains and oilseeds produced on millions of acres for the purpose of satisfying the world's food and feed demand.

Grain Quality Fact Sheets can be accessed on-line through the World Wide Web at: http://www.agcom.purdue.edu/AgCom/Pubs/grain.htm (select) Grain Quality or http://www.GrainQuality.org
 


ngin bulletin archive

INDEX