How's the air quality on the ISS? I think I remember seeing something about it smelling pretty bad, and I know I've seen terrible reports about the waste contai

How's the air quality on the ISS? I think I remember seeing something about it smelling pretty bad, and I know I've seen terrible reports about the waste containment systems that were used on the shuttle. Stuff like that isn't quite as sexy as a big volume, but I would think it is at least as important to solve, if not quite a lot more important.