LATE IN THE SUMMER OF 2002, USDA inspectors examined a field just miles from Curt Carlson's Nebraska farm, where another farmer grew a small test plot of ProdiGene corn that was engineered to make a vaccine for fighting a diarrhea-
causing virus in pigs. He'd grown the ProdiGene corn the year before, then switched his field to soybeans, which he grew for veggie burgers and infant formula. During its inspection, the USDA found a few small diarrhea-vaccine corn plants, so-called volunteer plants that had sprouted in the midst of the soybeans without being planted. The USDA, concerned that drug corn might get into the food supply, immediately told the farmer and ProdiGene to destroy the plants. For some reason, that didn't happen -- and in early October, the farmer harvested his soybeans and delivered them to the Aurora Co-op, a local grain elevator, where they were to be stored before shipping. By the time the USDA inspectors returned to the soybean field and found the remains of the volunteer corn plants mixed with soybean stubble, a few leaves and stalks from the pharm corn had contaminated 500,000 bushels of soybeans from dozens of farms -- enough soybeans to fill more than 550 tractor trailers. Before the co-op started shipping them to makers of vegetable oil, soy milk and other foods, the USDA quarantined the contaminated Aurora soybeans. The news broke worldwide, and critics were outraged, blasting ProdiGene for carelessness and the USDA for lax oversight.
In December, I stood with the Aurora Co-op's manager, Harlan Schafer, in a gravel yard as he pointed at a weathered white concrete silo as high as a 16-story building -- one of several the co-op uses to store crops before shipping them. Schafer, a square-jawed 43-year-old with thinning hair and a lopsided grin, pointed to a steel ladder on the silo. "This is the elevator you saw all over the world," he told me. On November 19, 2002, two protestors from Greenpeace climbed 100 feet up that steel ladder and hung a huge banner from a railing. The next day, newspapers worldwide carried images of the banner, which showed a giant red syringe injecting a black-and-white corncob, emblazoned with a stark message: "This is your food on drugs."
THE GM FOODS WE EAT TODAY are usually engineered with special genes from plants or bacteria, and they're specifically designed and tested for human consumption. Pharm crops, on the other hand, are made by inserting human and animal genes into crops. They've never been tested to see whether they're safe for human consumption, because humans were never supposed to eat them. And yet, as the Aurora soybean snafu demonstrated (and as Greenpeace pointed out with its usual flair), the potential benefits of pharming come with the risk that these drug crops may someday end up in our food supply.
Especially when the crop is corn. Soybeans and other crops reproduce by themselves, pollinating their own flowers to form seeds. But corn plants use each other to reproduce, and their pollen can travel long distances to "interbreed." That interbreeding makes corn "one of the worst crops you could possibly pick" for pharming, says Allison Snow, a plant ecologist at Ohio State University. "You cannot get 100 percent containment in corn," Snow says. "It's just not possible." Even if pollen could be contained, she says, corn seed, or kernels, can sprout where they're not wanted, as they did for Curt Carlson's neighbor in Nebraska. Birds, deer, rivers and high wind can move corn kernels; farmers can track them into fields on their shoes. Crops like soybeans that don't interbreed would eliminate much of that risk, as would using nonfood crops like tobacco -- as Large Scale Biology does for its lymphoma vaccine. But corn continues to be the most common pharm crop, largely because it's cheap and easy to cultivate, and it produces much more protein than alternative plants.