Here's how it does work: At a special irradiation plant—there are just a handful in the United States—workers zap food with a machine similar to the kind that administers radiation to cancer patients. Most facilities use electron beams, but some irradiate with X-rays or gamma rays. While the dose of radiation is high, it doesn't stay with the food, and workers are protected from it with safety gear and massive concrete walls. The result, says Michael Osterholm, a University of Minnesota expert on food-borne illness who has studied irradiation extensively, is that it kills as many bacteria as cooking at high temperatures, but without any loss of taste. "Food irradiation shows absolutely no detrimental impact on the food," he says.
Yet some food advocacy groups have campaigned vociferously against the technique. Food and Water Watch, for example, argues it might induce manufacturers to zap food instead of maintaining a clean plant. "This could be a gateway to faster line speeds at meat facilities and sloppier handling practices," says Patty Lovera, the organization's assistant director. But Rick Holley, a food microbiologist and irradiation expert at the University of Manitoba, sees the technique as an extra tool, rather than a crutch; irradiation, he points out, doesn't get rid of all bacteria, just most. "You can't make bad food good using irradiation," he says. "If your plant is dirty and not inspected and overtaxed, the food is going to be bad in a way that irradiation can't fix."
To be sure, the technology isn't cheap—but that, says Harlan Clemmons, who runs an irradiation facility in Sioux City, Iowa, is mostly because it costs a lot of money to ship all that meat to the special plants. Although the equipment is expensive (about $18 million up front), Clemmons calculates that if meat processors did irradiation in-house, over time they could bring the cost down "to next to nothing."
But that's unlikely to happen anytime soon unless consumers start embracing the technique, which might require more public attention. In a 2005 study, 484 shoppers at grocery stores in four Texas towns were asked about their opinion of irradiated foods. Then they read material about how an electron beam works and watched a short video on the topic. Initially, about 18 percent of the shoppers described themselves as "doubters" or "rejecters" of irradiation. But after the statements and video, that number dwindled to just 3.8 percent. Osterholm likens the public mistrust of irradiation to the anti-vaccine movement. "We know we could eliminate many food safety problems with this technique," he says. "And yet people are still fighting it."