Molds in the Environment

What is mold?

A mold is a microscopic fungus that grows and lives on plant or animal matter or on nonorganic objects. Most molds are made up of filaments and reproduce through the production of spores. Spores spread by air, water, or insects. There are many thousands of species of fungi. Common indoor molds include:

• Alternaria

• Aspergillus

• Cladosporium

• Mucor

• Penicillium

• Stachybotrys chartarum 

Molds are found everywhere in the environment, both indoors and outdoors, and throughout the year.

What are common reactions to mold?

Molds cause allergic symptoms in many people. Common reactions to molds include nasal stuffiness, eye irritation, or wheezing when breathing.

More severe reactions may happen among workers, such as farmers, who are exposed to large amounts of molds in occupational settings. These reactions include fever or shortness of breath. Mold infections may happen in the lungs of people with obstructive lung disease. People with weakened immune systems would be especially susceptible to infections from many different types of mold or fungi. 

How can mold exposure be decreased?

• Consider reducing your mold exposure inside:

  • Keep humidity levels between 40% and 60%

  • Ventilate showers and cooking areas with exhaust fans

  • Use an air conditioner or a dehumidifier during humid months

  • Don't use carpet in susceptible areas, such as bathrooms or basements

  • Dispose of, or thoroughly dry and clean, objects that accidentally get wet, such as carpets or upholstery

  • Fix leaks in roofs, walls, or plumbing to get rid of moisture

  • Add a mold inhibitor to paint when painting

  • Use mold-killing products to clean bathrooms

• Other sources of mold are:

  • Compost piles

  • Cut grass

  • Damp, mossy areas

  • Greenhouses

  • Saunas

According to the Federal Emergency Management Agency (FEMA), mold is one of the most serious results of water damage from a hurricane or severe floods. Mold can grow within 24 to 48 hours after water damage. It can keep growing until the correct measures are applied to stop it. The CDC states molds can be recognized by sight, such as wall or ceiling discoloration, and a bad odor or musty smell.

FEMA and CDC warn that returning to water-damaged homes after a disaster may pose serious health threats. This is especially true for people who already have preexisting respiratory conditions, pregnant women, children, older adults, and people with diseases that compromise the immune system. Always wear rubber gloves, goggles, and boots when cleaning areas with mold. 

FEMA and CDC have developed specific guidelines for cleanup of water-related disasters. Please talk with your healthcare provider with any questions or concerns you may have about this condition.