Irradiation of food is the process of exposing food to low level radiation in order to kill any germs or bacteria which may be on the food. This process can be cheaper and faster than other methods of eliminating bacteria.
Because irradiation kills things, (including workers in third world coulntries where the regulations are more lax, who got trapped in the irradiation chambers,) it can not be used on all foods such as muscles or clams which need to be killed just prior to consumption (unless they are canned). If, for instance, fruit is irradiated, than all of the enzymes which were contained within it are destroyed. It has been suggested that these enzymes have health benefits, so there is debate over whether or not irradiated food is less healthy. Irradiated food is often supplemented by adding vitamins.