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Health Agency | Public Health

County of San Luis Obispo

Mold Clean-Up and Prevention

What is Mold?

Molds release tiny spores and even smaller particles that travel through the air. Everyone inhales some mold every day without apparent harm; however, molds can cause allergy, irritation or inflammation, or rarely, infection.

Health Impacts of Mold

Allergic reactions are the most well-recognized responses to inhaling mold spores, and some people are more sensitive to the effects of dampness mold.  If you can see mold, water damage, or moisture, or smell mold, there is at least some increased health risk. The more extensive or severe the dampness and mold, the greater the risk of health effects. These can include:

  • Causation of new asthma

  • Asthma attacks in those who already have asthma

  • Allergic rhinitis (sneezing, congested nose, or runny nose)

  • Upper respiratory symptoms, such as stuffy or congested nose or sinuses, sore throat, or irritated nose or throat

  • Lower respiratory symptoms, such as wheezing, difficulty breathing, shortness of breath, or cough

  • Respiratory infections such as acute bronchitis

  • Eye irritation (burning, watery, or reddened eyes)

  • Eczema and skin rashes or irritation

Causes of Mold

Since mold requires water to grow, it is important to prevent moisture problems in buildings. Moisture problems may include:

  • Roof leaks

  • Inadequate ventilation

  • Landscaping or gutters that direct water into or under the building

  • Unvented appliances

  • Delayed or insufficient maintenance

Frequently Asked Questions

How do I clean up mold?

Surface molds grow in just about any damp location, such as the grout lines of a ceramic tiled shower. They're easy to scrub away with a mixture of 1/2 cup bleach, 1 qt. water and a little detergent.  Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy. Mold can grow on or fill in the empty spaces and crevices of porous materials, so the mold may be difficult or impossible to remove completely. For tips on mold cleanup, visit the EPA's website.

I found mold growing in my home. How do I test the mold?

Reliable sampling for mold can be expensive, and standards for judging what is and what is not an acceptable or tolerable quantity of mold have not been established.  Additionally, reactions can be based as much on individual susceptibility as it can on the amount or type of mold, therefore it is generally not necessary to identify the species of mold growing in a residence.  No matter what type of mold is present, energy should be spent on its removal and less on its identification. 

My landlord or builder will not take any responsibility for cleaning up the mold in my home. Where can I go for help?

If you feel your property owner, landlord, or builder has not been responsive to concerns you’ve expressed regarding mold exposure, you can contact your local board of health or housing authority. Applicable codes, insurance, inspection, legal, and similar issues about mold generally fall under state and local (not federal) jurisdiction. You could also review your lease or building contract and contact local or state government authorities, your insurance company, or an attorney to learn more about local codes and regulations and your legal rights.

What type of doctor should I see concerning mold exposure?

You should first consult a family or general health care provider who will decide whether you need referral to a specialist. Such specialists might include an allergist who treats patients with mold allergies or an infectious disease physician who treats mold infections. If an infection is in the lungs, a pulmonary physician might be recommended. Patients who have been exposed to molds in their workplace may be referred to an occupational physician.

Where can I find additional resources?