the federal government years ago," Sun believes. Twenty
countries now permit some use of the process, developed during the
1950s; several international agencies, including the World Health Or-
ganization, have certified the safety of medium-energy irradiation. But
in this country, the U.S. Food and Drug Administration (FDA) has
barred all but a few uses. Food prepared for U.S. astronauts in space
and for people suffering from immune system deficiencies, for example,
is sterilized irradiation....