You might be confused between mould and black mould. Black mould is also a kind of mould resulting more dangerous effects to the nature and mankind. Skin infection,asthma,lungs disease etc. are few diseases affected by this. So it is better to remove it with the help of some specialists in your location. Here I found some additional information about Black mould removal, http://www.healthyenvironmental.ca/services/black-mould-removal.
Hope it helps