Here in the States you can get some company to test for mold in your house. It costs about $500. I know, not cheap but if I continue to have a problem in this house, I just might do it. Anthony is right: mold is everywhere but black mold is the really dangerous stuff. It can lead to lung damage and so I hear, lots of other terrible illnesses. If the mold level in your house is way higher than advisable limits, then I'd suggest getting some professional to assess ways to eliminate it. Air cleaners might help. In the long run it's cheaper than selling your house and moving (not that we can do that!) and anyway, no one wants to suffer like this until the day we kick the bucket! Sigh... :( (Remember me? I'm the one going through what you went through 2 years ago with your plumbing leak.)