March 13, 2003
AMES, Iowa — No one knows with scientific certainty the likelihood or extent of risks from genetically modified plants not grown for food or feed, such as biopharmaceuticals.
Iowa State University researchers are leading an effort to help find the answer within a year.
They will develop a risk assessment tool based on science that can be used to make public policy decisions about growing biopharmaceutical-producing crops.
The tool will be designed to identify potential containment risks in the steps of growing a biopharmaceutical crop, from seed to end-use. It also will indicate points for intervention where scientific safeguards are needed.
The researchers also will use the tool to assess the risk of safely containing the production of two selected proteins that could be used to produce biopharmaceuticals in corn.
Iowa and other corn-producing states are actively pursuing the pharmaceutical crop industry, which holds significant economic potential. Critics, however, say the crops should not be grown in food-producing states because of possible contamination of the food supply.
There is a third option, says project leader Manjit Misra, professor of agricultural and biosystems engineering and director of the Seed Science Center at Iowa State.
"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," Misra said.
"We want to develop a scientific framework to assess the safe production of biopharmaceutical crops in food-producing states," he said.
The Iowa State researchers—along with scientists from the University of Iowa, Iowa City, and Montana State University, Bozeman—will follow the National Research Council's established risk analysis procedures to develop the model.
About 35 to 40 plant-made pharmaceuticals and industrial products are nearing commercialization, Misra said.
Guidelines proposed by the Federal Drug Administration and the U.S. Department of Agriculture for raising genetically modified crops for pharmaceuticals are based on a zero tolerance for the inadvertent introduction of these products into food or feed supplies.
"Our project 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," Misra said. "The tolerance standard should be based on the risk as established through scientific methods."
Misra said risk assessment is a function of hazard and exposure. "It's a function of how hazardous or harmful an agent is and how often we get exposed to it," he said.
The ISU-led team of agronomists, geneticists, economists, statisticians and public health specialists will begin their project by classifying each protein as harmful, less harmful or benign, based on the analysis of published scientific information.
Next, they will develop a systematic flow diagram of each step in the process, from the insertion of the protein in the plant to the consumption of the crop.
"We'll lay out each of the hundreds of operations and sub-operations where the genetically modified crop could possibly contaminate the food supply," Misra said.
A panel of faculty who are authorities in their fields (such as plant transformation, seed production, pollen flow, grain harvest and distribution, food quality and risk calculation) will quantify the probability of contamination at each step, Misra said.
"For some operations, such as grain harvesting, we will assign different probabilities based on different management practices—for example, the equipment and procedure used for harvesting and handling of grain," Misra said.
The researchers will then statistically calculate an overall risk for each of the production management pathways the genetically modified corn could follow through the entire process.
The final product will be a template that sets forth the process by which plant-made pharmaceuticals can be evaluated in a scientifically sound manner.
It will be made available to state and federal agencies and discussed in scientific and public forums, Misra said.
Safety should be the defining issue, not geography, Misra said. "The main issue should be the adoption of effective, science-based methods that ensure that pharmaceutical crops can be produced in a safe, responsible, well-managed and environmentally friendly manner that safeguards valuable agricultural resources."
A university-funded program on risks and benefits of genetically modified agricultural products, involving the Plant Sciences Institute, the College of Agriculture, the College of Veterinary Medicine, the Office of Biotechnology and ISU Extension, coordinates the research.