According to the Energy Star website, mold and mildew can cause a strong, musty odor in a building or home. Mold and mildew are often formed in places with high humidity or water leaks.
Information from the University of Georgia's Department of Housing and Consumer Electronics explains that the musty odor of mold and mildew is one of the main symptoms of the problem. Mold and mildew can form on a variety of surfaces, even paper, wood and leather.
Mold and mildew forms in areas with poor ventilation; therefore, increased ventilation often removes the damp, musty odor. The University of Georgia explains that increasing heat levels in the problem area can also help remove mold smells.
The University of Georgia reports that certain chemicals can help destroy mold and mildew smells, such as chlorinated lime spread on infected areas and left until the odor disappears. On hard surfaces, such as cement and tile, chlorine bleach can be used to clean moldy areas. Read the instructions carefully before applying bleach or chemicals to any surface.