Heh - Granite
My nearly 150 year old home's basement is made from gigantic granite blocks. ZOMG The tra-gee-dee !!!11!! And here I am, alive and amazingly cancer free..
And Denver Colorado -- Might as well evacuate the entire city !!!11!!!! as well as the entire state of New Hampshire..
Here is a clue, primitives. SOME forms of radiation are dangerous, but as a species, we evolved surrounded by it. Small amounts of exposure aren't going to kill you, nor will it give you cancer, make you sterile, or all of the other crap the anti-nuke gang have been chirping about since Hiroshima & Nagasaki.
What radiation flies over will be both degraded, and spread out over a wide area - your exposure will be negligible at best. 'Heavy Hydrogen' is the only stuff that will make it over without degrading, but its radiation is so weak it cant penetrate skin. The nitrogen will be fully degraded, as its half-life is 7 seconds, and the iodine will be mostly degraded, as its half-life is 8 days. There is no report of any massive release of anything more deadly.
*Yes, I know that the granite post was in jest - but I also know that some chicken-little DUmmy idiots are gonna panic over granite.