Re: variations in background

["Richard L. Hess" <lists@richardhess.com>]

Mike,



I'm just a hobbiest in this, but at my office on the 10th floor in 

Glendale, California I measured approx 75mR/y. At my home (also in 

Glendale, CA), the worst I've seen is about 125mR/y. I live very near (cut 

into, actually) decomposed granite.



I've measured 125µR/h at cruise altitude between New York and Chicago.



I know this is not what you're looking for, but I thought a spot 

measurement somewhat lower than your average might be of use.



I've also logged (using 15-minute averages) a long driving trip up I-15 

through Glacier National Park to Winnipeg, down through Yellowstone and 

back and, on average, almost no 15 minute periods exceeded 12µR/h. These 

were better shielded in the center console of my Suburban, however.



I did note 24µR/h on the lip of the Berkeley Pit in Butte, MT.



The Canadian Prairies were uniformly measuring 9µR/h.



A recent trip to Cambria, California had similar results.



A colleague of mine started me on this quest when I showed him the route I 

was driving up through MT and ID and he said, "I wouldn't drive this route 

without a Geiger counter". Well, I did drive it with a Geiger counter and 

now feel much better about the "scare" stories out there.



Cheers,



Richard