The human response to most long-term mold exposures is to develop an allergy--inappropriate or exaggerated reactions of the immune system, trying to protect itself. Allergens are the substances that provoke these reactions; for most people, mold is an allergen.
So what can we do to prevent mold allergies?
You really can not prevent an allergy. The only thing you can do is to try to prevent exposure to allergens so the body does not have to defend itself with an allergic reaction. That is one of the reasons it is crucial to clean up mold before it becomes seriously entrenched.
How can you prevent mold? Some simple rules:
Remove existing mold.
Eliminate water leaks.
Use Hepa filtration and electrostatic filtration to reduce spore count.