I have heard that if you have serve as cabin crew for over three years that you can no longer donate your organs to medical science due to internal damage. (from a friend of a friend who works on an airline). The airline apparently informs staff of this ‘fact’ when they begin work.
Is this correct in either:
There are warnings from airlines about this potential hazard, or
There is a possibility for internal organ damamge due to constant and sustained flying.
Either? Neither?
Thanks.
Well… I do around 800 hours of flying per year and no one has ever informed me that I can’t donate my organs.
Sets my BS meter off frankly.
Mine too, that’s why I’m asking. 
Anyone else heard this from any other sources?
Is there any medical condition that prolonged time in a pressurised cabin could theoretically cause, that may have begun this ‘rumour’?
I haven’t heard of such a rule. It’s well known, though, that a long time spent in airplanes at high altitude will expose you to an additional radiation dose that’s small but not negligible compared to normal background exposure. See e.g. this Straight Dope column
I don’t see why this would militate against donating your organs to medical science, though. I’d have thought the organs would be the more interesting for it…
The only thing other than above mentioned radiation increase, that frequent flyers experience is slightly low ambient air pressure. However, the normal cabin altitude of a commercial airliner is around 8,000’. This is hardly abnormal stuff, a lot of people live at higher altitudes than that. In addition to this, there is the frequent change in air pressure, this generally has little effect other than making you fart and your head explode if you have blocked sinuses 
There is also the possibility of blood clots forming in the legs, but this is due to inactivity and cabin crew themselves are generally fairly active.
I am unsure of where this type of rumour (if that is what it is) would have come from.