More than 100 years have passed since heat-pasteurized milk was first introduced to the public, and few people today would argue against its benefits. The situation was very different, however, when the idea of sterilizing milk by heating it was first proposed. Critics questioned the need for pasteurization and expressed concerns about its safety.
A similar situation is now brewing over the irradiation of foods, a procedure designed to destroy potentially harmful organisms and improve the safety of the food supply. With this process, high-energy, invisible light waves are passed through food to kill bacteria and other dangerous organisms or to prevent them from reproducing. Since the high-energy waves affect only cells that are alive and growing (like bacteria), the food itself--which is "dead"--remains essentially undisturbed.
*
The health benefits of irradiation are most obvious for raw food products, such as poultry and meat, that are often contaminated with bacteria known to cause disease. Poultry, for example, often harbors salmonella and campylobacter; ground beef may harbor E. coli O157:H7. Irradiation also offers an extra margin of safety for raw fruits and vegetables that can acquire dangerous organisms from the soil or from post-harvest handling.
Irradiation may reduce the need for other types of pest controls such as pesticides and fumigants, lowering the amount of chemical residues on and in these foods. In certain fruits and vegetables, irradiation inhibits sprouting and delays ripening. This reduces spoilage and extends shelf-life (for example, irradiated strawberries remain unspoiled for up to three weeks, compared with three to five days for untreated berries).
In spite of these benefits, there is significant opposition to irradiation, much of it based on fears that irradiation will leave food "radioactive" and, therefore, potentially dangerous. This concern is unwarranted. Scientific studies prove that irradiation leaves no signs of radioactivity in food. Although the gamma rays, X-rays or electron beams used to treat food are created by radioactive sources, the food never comes into direct contact with the radiation source.
Some chemical changes do occur during irradiation, but these changes are similar to the ones that occur with other food preservation methods, such as cooking and canning. The chemical byproducts of irradiation have been closely studied and found to be safe.
