Scientists scrutinize biopharming

Researchers in US breadbasket states are developing an assessment model to identify potential safety risks in growing biopharmaceutical crops. The team from Iowa State University, University of Iowa and Montana State University hopes that finding a reliable way to predict the risk of food-crop contamination will help to resolve controversy over whether biopharming can safely take place near the nation's food supply."Instead of saying we should or shouldn't grow the pharmaceutical crops in food-producing areas, we're using science to determine which ones are safe to grow in food-producing areas, which ones should be grown in other states, and which ones should not be grown in an open environment at all," said Manjit Misra, lead researcher on the project and director of the Seed Science Center at Iowa State.Concerns about cross contamination surged following the StarLink corn incident in 2000, when genetically modified corn approved only for animal feed found its way into the human food supply. More recently, biopharmaceutical crops—plants engineered to produce proteins for use in vaccines, drugs or as industrial chemicals—have come under fire from consumer and environmental groups as well as increased scrutiny by the US Department of Agriculture (USDA). Last fall, USDA investigated and punished the Texas biotech ProdiGene for two incidents involving potential contamination of a food-crop field and a storage facility by the company's pharmaceutical crops. So far, no biopharm crops have been approved for commercial use, although nearly 40 plant-made pharmaceuticals and industrial products are nearing commercialization. This month, the USDA announced tighter restrictions on biopharmaceutical test fields including a one-mile buffer zone around the crops and at least five USDA inspections during each growing season. The proposed new risk-assessment model will involve a systematic flow diagram of each step from insertion of the protein into the plant to the harvesting of the crop. According to Misra, various experts will determine risk at each of the hundreds of operations and sub-operations where the genetically modified crop could possibly contaminate the food supply.Although the goal set forth by the USDA is zero percent contamination, the risk assessment model, Misra said, "will take the approach that tolerance levels should be defined for each pharmaceutical or industrial product and relate to any potential health or environmental hazard the product might pose."However, Jan Rissler, a plant pathologist and deputy director of the Food and Environment Program at the Union of Concerned Scientists describes the researchers' model as "well-meaning but naïve.""It's understandable that [researchers from farming states] would try to develop something like this," Rissler told The Scientist. "Iowa has invested millions in this technology, and they see it as a way for their farmers to succeed with a valuable crop." But she stressed that what the food industry and consumer groups want is "zero percent contamination of the food supply with these chemicals, period."This sort of approach is fraught with all sorts of problems," Rissler continued. "Once you set an acceptable level, how do you know the level is not being exceeded? It would require a very stringent risk assessment for each product."According to Rissler, zero percent contamination is achievable, but would require strict measures. One of which might be to not use food crops such as corn for biopharming at all. A non-ingested plant such as kenaf, used to make paper, might be a more viable alternative, she said.Gregory N. Mandel, assistant professor at Albany Law School in New York and a specialist in the regulation of genetically engineered products said, "the idea of this model sounds like a step in the right direction." While he agrees in principle with the idea of zero percent contamination, Mandel said there's no way to say that the USDA guidelines will guarantee it. "Pollen flow and gene transfer are very poorly understood," he said, adding that buffer zones widths set by the USDA appear to be "arbitrarily set.""We might need to get away from the idea of zero percent contamination," Mandel noted. "Any level of pharmaceutical production carries risk, and the risk may be worth it, but this idea has yet to be fully analyzed."

Scientists scrutinize biopharming

US team developing risk-analysis tool to assess dangers to food supply.

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