Re: Cosmic ray background in Denver

[Wes Van Pelt <VanPeltW@IDT.NET>]

John Moulder wrote:
> 
> Not a trivia contest, but I urgently need to know what the cosmic ray
> background is in Denver.
> 
> Im looking at a statement that comic background averages 20 mrem/yr in the US,
> but is 50 mrem/yr in Denver.  I know that the 20 mrem/yr average is a bit low,
> 30 mrem/yr would be closer, but what about the Denver figure?
> 
> Please reply by e-mail, as I get radsafe by digest, which is handy but delays
> replies.
> 
> John Moulder (jmoulder@its.mcw.edu)

Hi John,

I pulled out NCRP Report No. 94, "Exposure of the Population in the US
and Canada from Natural Background Radiation", 1987.  Reading from the
graph on page 15, the cosmic radiation dose rate is :

At sea level:
30 mrem/y  tissue dose equivalent rate
28 mrad/y  absorbed dose rate in air

At 1.6 km above sea level:
51 mrem/y  tissue dose equivalent rate
47 mrad/y  absorbed dose rate in air

Hope this helps,  Wes

-- 
Wesley R. Van Pelt, Ph.D., CIH, CHP                KF2LG
President, Van Pelt Associates, Inc.     
Consulting in radiological health and safety.
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