Much of the uranium country in western Colorado and eastern Utah is naturally "hot." By the way, red brick often has enough radiation to register on a Geiger counter. The red clay often contains Thorium and the firing process will concentrate it in the brick. Radon gas is so common in the soils of many areas of the Rocky Mountain West (the heavily populated Front Range of Colorado being one) that many basements and crawl spaces now are required to have exhaust fans to change out the air in them Some jurisdictions require radon testing before a home can be sold.
Years ago, the old mill site at Vanadium was "hot" enough that it would register on a Geiger counter while you drove by it. And, of course, there was the many millions of dollars spent to remove mill tailings that had been used for fill all over Grand Junction, Colorado in the 1950's. Oh, and don't forget the uranium mill at the old smelter site in Durango. From the 1940's until the early 1980's, when the tailings were removed and buried (again, at huge taxpayer expense), every time the wind would blow from the south or west, the Durango railroad yard and most of the downtown would get covered with radioactive dust. I would bet that if someone ran a Geiger counter around any of the remaining narrow gauge freight equipment, is might show a "blip" from the times that it sat in Durango. Of course, some of the old narrow gauge boxcars still around might have been ones that carried the ore for the first A-bombs.
Edited 1 time(s). Last edit at 01/17/2016 08:17AM by Wade Hall.