In the US, all gauges built with radium paint have to be refurbished with modern, non-radium paint prior to being certified for flight as a primary flight instrument. This has some to do with the radioactive issue (an I've run a Geiger over some un-refurbished instruments and it's amazing the count, although not harmful in normal exposure, in an enclosed stale atmosphere, I can see how it might build up to something worrisome). Most gauges made up through the 1970s used Radium instead of the much safer Tritum.
As has been said before, the problem isn't the undisturbed instruments as much as the degredation of the paint that holds the tritium and thus much of the radiation in. We have to remember that when this was a "normal" thing to do, radiation and its effects on humans (much less animals) was very poorly understood, so these things were done in ignorance. One can only imagine how they would have reacted had they known how dangerous it was to use it, much less MAKE the paint.
The difference is staggering. A pocketwatch with a "typical" amount of radium paint gave a dose of 60 mrem per year (although concentrated to the lower body). A pocketwatch with the same amount of tritium paint only gave a dose of ~0.6 mrem per year. An aircraft instrument used about double the amount of paint as a pocketwatch to meet U.K Admiralty luminescence regulations, so that's at least 120 mrem per year (the pocket watch is based on a 16 hour per-day exposure, but consider there's more than 1 radium painted instrument). That's just under half of what a smoker increases his/her exposure per year (280 mrem), and almost a third of the total exposure per year (380 mrem). So, your exposure, while not "life threatening" can make your risk for various radiation-related health issues elevated.
Personally, I would rather be safe than sorry on that issue.
Soucres:
http://www.orau.org/ptp/collection/radi ... ntinfo.htm
http://web.princeton.edu/sites/ehs/osra ... ground.htm
