Have an old Victoreen Geiger counter and have seen some interesting things: - Munich: Chernobyl (obvious high background radiation) - Arizona: Fukushima (noticeably higher background radiation)

Also, my wife had a test requiring an injection of a radioisotope and the meter was moving (many counts per second) when placed within several feet of her. So an EDC motive might be to monitor whether a colleague got such an injection and decided to come to the workplace.