[ RadSafe ] Ancient background radiation

[Kulp, Jeffrey B]

Hello Radsafers,

I once read that background radiation from terrestrial sources was estimated to be approximately an order of magnitude greater than its current level; due to relatively short lived transuranics that decayed to U and Th. I have tried to find references to this; I have been unsuccessful. Has anyone else heard or read this, and can you point me in the direction of documents or a website that contains the information?

Thanks,

Jeff Kulp
Washington State University
Radiation Safety Office
Pullman, WA 99164-1302
(509) 335-8175