The process damages their genetic material, so the organisms can no longer survive or multiply. Irradiation does not make food radioactive and, therefore, does not increase human exposure to radiation. The specified exposure times and energy levels of radiation sources approved for foods are inadequate to induce radioactivity in the products, according to FDA's Laura Tarantino, Ph.D., an expert on food irradiation. The process involves exposing food to a source of radiation, such as to the gamma rays from radioactive cobalt or cesium or to x-rays. However, no radioactive material is ever added to the product.
Manufacturers use the same technique to sterilize many disposable medical devices.
Tarantino notes that in testing the safety of the process, scientists used much higher levels of radiation than those approved for use in poultry. But even at these elevated levels, researchers found no toxic or cancer-causing effects in animals consuming irradiated poultry. Beyond the Gamma Alarm Market tests show that once consumers learn about irradiation, they will buy irradiated food. For example, Christine Bruhn, Ph.D., of the University of California's Center for Consumer Research in Davis, Calif., reports that irradiated papayas outsold the nonirradiated product by more than 10 to 1 when in-store information was available. And, Danny Terry, Ph.D., a consumer researcher at Central Missouri State University in Warrensburg, Mo., says that a recent market test he conducted with irradiated strawberries showed that consumers who received written information about irradiation along with the fruit were slightly more interested in buying irradiated products in the future.