My fiancee has been wheezing bad l and short of breath, i told my landord i see black mold, could this be causing it because he never felt like this.

If allergic: Everybody blames mold like it's legionaire's disease. Unless he has an immune deficiency, the odds of a fungal lung infection are low. However if he's allergic to mold, it can cause irritation of the airway that can aggravate asthma. Sometimes the mold can cause a mild irritation without having an allergy, but having a sensitivity already causes a worse reaction.