Is there anything more recent and authoritative for summarizing average annual radiation exposure in U.S. than NCRP-93 (published in 1987)? Are any of the figures given there changed by later info? Bernard L. Cohen Physics Dept. University of Pittsburgh Pittsburgh, PA 15260 Tel: (412)624-9245 Fax: (412)624-9163 e-mail: blc+@pitt.edu