Very easy way to test for a radioactive lens. Only costs you a single sheet of film.

Take you lens into your darkroom. If you have no darkroom, use a changing bag or tent. If none of the above, make temporary darkroom - like a closet at night. In you darkoom, take out a single sheet of B&W film. I used HP5, 4x5 for my test. Faster ASA / ISO seems to work a bit better.

Leave the lens, in the dark, or in the changing bag overnight , but better for 24 hours, on top of the sheet of film. If you notice brown or brownish or browner elements on one side of your lens, but that side directly down touching the film.

Next day develop that sheet of film as you would a if you exposed it on a regular basis. A "hot" lens will show all sort sof little streaks, comet like little asterix marks, etc. Kinda cool actually. You'll know it when you see it. It's the radiation fromt eh lens striking the emulsion that does it.

I did this with my Aero - Ektar lens, and it was kinda cool. Today I had a rad detector for such things, but this is an easy way to find out for sure. The only thing I cannot tell you is how "hot' the lens is, but I would assuming sitting down and watching a movie with the lens on your lap is maybe not a good idea.

joe