RE: Ancient radiation levels were higher than today's levels

["Heinmiller, Bruce" <heinmillerb@aecl.ca>]

Am I out-of-date on natural radiation dose?  The latest UNSCEAR estimate I
have is two-thirds of the datum quoted here, and even that's rumoured to be
coming down by another 10% or so, largely because of a revision in the dose
coefficient for radon.  I assume the quantity of interest is the
world-population average effective dose from natural sources, including
natural but anthropologically enhanced indoor radon and direct enhanced
exposures from building materials and other minor NORM.  I believe that's
what UNSCEAR considers.

Bruce Heinmiller CHP
heinmillerb@aecl.ca

> > forms.  Presently, humans receive a dose of about 360 millirems per
> > year of radiation from natural sources, plus typically about 63 mrem/yr
> > from anthropogenic sources.  Perhaps surprisingly, a major source
> 
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html