An effort has been made to show what is being done by the AEC, the PHS, and other Federal and local agencies to measure the amount of radioactivity contributed from a multiplicity of sources and relate their data to potential public health implications. There is a need for more data of this nature, particularly in terms of the specific radionuclides present in food materials grown all over the nation and the world. With such information on hand, we shall be able to define with a greater degree of accuracy the public health implications of such radiation levels and to provide a better basis for developing more realistic maximum permissible concentration levels in a greater variety of environmental media. (Author)