Originally Posted by
Yamagata ken
I used to wear my father's WWII issue watch to school. In one physics demonstration, the teacher used tweezers to remove a radioactive sample from its protective box and pass a geiger counter over it. It gave a reading. He asked for volunteers and I handed over father's watch for testing. The geiger counter went off-scale. Oops.
Similar experience in 1975, a friend's watch produced an impressive response from the geiger counter. He stopped wearing it after that!
The hazard described here is not so much direct radiation at the wrist as radon released into the air indoors.