Yup, M-O-L-D : the new dirty word (unless, of course, you’re talking about a great Stilton cheese).
Remember R-A-D-O-N? Well, there are still areas of the country that DO, in fact, have real issues with radon. I can’t exactly tell you what they are – this post is about mold.

More and more people are discovering how much of a role mold (or the lack of it) plays in one’s health. More and more home inspectors are including mold testing in the home inspection services. So read up on it a little. Along with underground oil tanks, it can be a deal breaker.

Caution: also be careful whom you hire for mold remediation. It’s become a “get rich quick” scheme for some – the same guys that were installing thousand-dollar water filters in homes in the late 1980’s. Not all are evil, but deal with someone who’s recommended to you. md

There’s quite a bit of information here:
NAR info Centers Field Guide to Mold and Health Issues