RE: [many times over] radiation is radiation

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

Note that (and contrary to countless glossy pamphlets) the cosmic-ray dose
delivered to the human population is almost exclusively from sources other
than the sun.  Indeed, aside from the infrequent and brief occurrence of a
very large solar flare, periods of maximum solar activity (such as the one
we're coming into this year or next) are associated with minimum cosmic-ray
dose rates, because of interaction of the solar-wind magnetic fields with
the galactic cosmic rays entering the solar system.  Some of the galactic
cosmic rays are deflected away from the solar system by this interaction.

Solar cosmic rays generally are too low in energy to penetrate very far into
the atmosphere.  Galactic and extra-galactic cosmic rays, on the other hand,
have an energy spectrum whose upper end is so high in energy that a single
one of these primaries can create a cascading shower of a billion
high-energy secondaries, many easily reaching sea level.

Bruce Heinmiller CHP
heinmillerb@aecl.ca

> ----------
> From: 	Vernig, Peter G.[SMTP:Peter.Vernig@med.va.gov]
> Reply To: 	radsafe@romulus.ehs.uiuc.edu
> Sent: 	Wednesday, May 10, 2000 5:41 PM
> To: 	Multiple recipients of list
> Subject: 	RE: [many times over] radiation is radiation
> 
> 
> It should be noted that NCRP lists 5 components to background; cosmic,
> cosmogenic, terrestrial, inhaled, and in the body.  Cosmic from the sun's
> fusion; cosmogenic from reactions of cosmic rays with atmosphere producing
> C-14 [carbon dating]; & H-3 and others; terrestrial, natural uranium and
> thorium decay sequences + K-40 & Rb-87; inhaled = decay products of radon
> [in turn a decay product of radium part of the natural uranium decay
> chains].  The in tissue component is complicated as it includes isotopes
> that are formed cosmogenically, from terrestrial sources and Po-210 from
> cigarette smoke and fallout.
> 
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