paleo-health physics

["Karam, Andrew" <Andrew_Karam@URMC.Rochester.edu>]

So then the statement, "presently, humans receive...", actually means,
"presently, biota in contact with geologic and biologic materials
receive..."?

Bruce Heinmiller
heinmillerb@aecl.ca
----------------------
The writer, when he contacted me, asked for total background exposure levels
and for anthropogenic contributions.  I cited the NCRP value of 360 mrem/yr
from all sources and a total of 63 (x-ray, medical, consumer products) for
artificial.  Unfortunately, I think I was not clear about the fact that the
63 was included in the background figure of 360 mrem/yr.  So, in the Physics
News Update blurb, the statement refers to average exposure to humans from
all sources and our exposure to background beta-gamma radiation would be
about 160 (since 200 mrem/yr were assigned to radon).  Of this, about 100
mrem/yr is from natural sources, including geologic materials, internal
emitters, cosmic and cosmogenic dose.

Another way to look at it is that we have calculated historical doses from
only two of the many source terms that exist.  We're working on the others!

Andy

Andrew Karam, CHP              (716) 275-1473 (voice)
Radiation Safety Officer          (716) 275-3781 (office)
University of Rochester           (716) 256-0365 (fax)
601 Elmwood Ave. Box HPH   Rochester, NY  14642

Andrew_Karam@URMC.Rochester.edu
http://Intranet.urmc.rochester.edu/RadiationSafety

We cannot prove that those are in error who tell us that society has
reached a turning point, that we have seen our best days.  But so said
all before us, and with just as much apparent reason.  On what principle
is it that, when we see nothing but improvement behind us, we are to
expect nothing but deterioration before us?    Lord Thomas B. Macaulay,
1830

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