This may be a lost cause, but I figure it can't hurt asking.

I just moved into an apartment in an oldish building- from the 1940s I believe. The bathroom is has no external walls, and judging from the black mold I've found, pretty significant dampness problems. As far as I can tell, there's no ventilation in place. I was wondering If anyone had some brilliant thoughts on how to vent the room. I'm sure I can't make any penetrations in the exterior walls, so this might be a lost cause.

I'll be replacing the floor, since the mold is well entrenched in the grout, but it would be nice to treat the cause of the problem and not just the symptom, if at all possible.

Thanks in advance for any input!