Molds grow throughout the natural and built environment. Tiny particles of mold are present in indoor and outdoor air. In nature, molds help break down dead materials and can be found growing on soil, foods, plant matter, and other organic matter. Molds produce microscopic cells called “spores” which are very tiny and spread easily through the air. Live spores act like seeds, forming new mold growths (colonies) when they find the right conditions. Mold only needs a few simple things to grow; moisture, nutrients, and a suitable place to grow. Of these, controlling excess moisture is the key to preventing and stopping indoor mold growth.

Mold should not be permitted to grow indoors. When this happens, health problems can occur and building materials, goods and furnishings may be damaged.

The type and severity of health effects that mold may produce can vary greatly from one location to another, over time, and from person to person. People that may be affected more severely and sooner than others are usually: Infants and children Elderly people, individuals with respiratory conditions or sensitivities such as allergies and asthma, persons having weakened immune systems (for example, people with HIV infection, chemotherapy patients, organ transplant recipients).

Although other and more serious problems can occur, people exposed to mold commonly report problems such as:
- Nasal and sinus congestion
- Cough
- Wheezing/Breathing difficulties
- Sore throat
- Skin and eye irratation
- Upper respiratory infections

For frequently asked questions about mold, click here.