Health Questions Answered
- What are molds?
Molds are fungi that can be found both indoors and outdoors. No
one knows how many species of fungi exist but estimates range from tens
of thousands to perhaps three hundred thousand or more. Molds grow best
in warm, damp, and humid conditions, and spread and reproduce by making
spores. Mold spores can survive harsh environmental conditions, such as
dry conditions, that do not support normal mold growth.
- What are some of the common indoor molds?
Cladosporium
Penicillium
Alternaria
Aspergillus
- How do molds affect people?
Some people are sensitive to molds. For these people, exposure to
molds can cause symptoms such as nasal stuffiness, eye irritation,
wheezing, or skin irritation. Some people, such as those with serious
allergies to molds, may have more severe reactions. Severe reactions
may occur among workers exposed to large amounts of molds in
occupational settings, such as farmers working around moldy hay. Severe
reactions may include fever and shortness of breath. Some people with
chronic lung illnesses, such as obstructive lung disease, may develop
mold infections in their lungs.
- Where are molds found?
Molds are found in virtually every environment and can be
detected, both indoors and outdoors, year round. Mold growth is
encouraged by warm and humid conditions. Outdoors they can be found in
shady, damp areas or places where leaves or other vegetation is
decomposing. Indoors they can be found where humidity levels are high,
such as basements or showers.
- How can people decrease mold exposure?
Sensitive individuals should avoid areas that are likely to have
mold, such as compost piles, cut grass, and wooded areas. Inside homes,
mold growth can be slowed by keeping humidity levels between 40% and
60%, and ventilating showers and cooking areas. If there is mold growth
in your home, you should clean up the mold and fix the water problem.
Mold growth can be removed from hard surfaces with commercial products,
soap and water, or a bleach solution of 1 cup of bleach in 1 gallon of
water.
- If you choose to use bleach to clean up mold:
- Never mix bleach with ammonia. Mixing bleach and ammonia can produce dangerous, toxic fumes.
- Open windows and doors to provide fresh air.
- Wear non-porous gloves and protective eye wear.
- If the area to be cleaned is more than 10 square feet, consult the U.S. Environmental Protection Agency (EPA) guide titled Mold Remediation in Schools and Commercial Buildings. Although focused on schools and commercial buildings, this document also applies to other building types. You can get it free by calling the EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318, or by going to the EPA web site at www.epa.gov/mold/mold_remediation.html.
- Always follow the manufacturer’s instructions when using bleach or any other cleaning product.
- Specific Recommendations:
- Keep the humidity level in the house between 40% and 60%.
- Use an air conditioner or a dehumidifier during humid months.
- Be sure the home has adequate ventilation, including exhaust fans.
- Add mold inhibitors to paints before application.
- Clean bathrooms with mold killing products.
- Do not carpet bathrooms and basements.
- Remove or replace previously soaked carpets and upholstery.
- I found mold growing in my home, how do I test the mold?
Generally, it is not necessary to identify the species of mold
growing in a residence, and CDC does not recommend routine sampling for
molds. Current evidence indicates that allergies are the type of
diseases most often associated with molds. Since the susceptibility of
individuals can vary greatly either because of the amount or type of
mold, sampling and culturing are not reliable in determining your
health risk. If you are susceptible to mold and mold is seen or
smelled, there is a potential health risk; therefore, no matter what
type of mold is present, you should arrange for its removal.
Furthermore, 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.
- Mold in My Home: What Do I Do?
READ
- See our Health Resources for Everyone
- The California Department of Health Services Indoor Air Quality Info Sheet.(PDF)
- U.S. Environmental Protection Agency Indoor Air Mold/Moisture (PDF)
- U.S. Environmental Protection Agency Mold Moisture and Your Home (PDF)
- A qualified environmental lab took samples of the mold in my home and gave me the results. Can CDC interpret these results?
Standards for judging what is an acceptable, tolerable, or normal
quantity of mold have not been established. If you do decide to pay for
environmental sampling for molds, before the work starts, you should
ask the consultants who will do the work to establish criteria for
interpreting the test results. They should tell you in advance what
they will do or what recommendations they will make based on the
sampling results. The results of samples taken in your unique situation
cannot be interpreted without physical inspection of the contaminated
area or without considering the building’s characteristics and the
factors that led to the present condition.
- 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. CDC is not a
clinical facility. CDC does not see patients, diagnose illness, provide
treatment, prescribe medication, or provide referrals to health care
providers.
- 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. CDC does not have enforcement power in such matters, nor
can we provide you with advice. You can contact your county or state
health department about mold issues in your area to learn about what
mold assessment and remediation services they may offer. You can find
information on your state’s Indoor Air Quality program at www.cdc.gov/nceh/airpollution/indoor_air.htm.
- I’m sure that mold in my workplace is making me sick.
If you believe you are ill because of exposure to mold in the
building where you work, you should first consult your health care
provider to determine the appropriate action to take to protect your
health. Notify your employer and, if applicable, your union
representative about your concern so that your employer can take action
to clean up and prevent mold growth. To find out more about mold,
remediation of mold, or workplace safety and health guidelines and
regulations, you may also want to contact your local (city, county, or
state) health department.
You should also read the U.S. Environmental Protection Agency (EPA) Guidelines, Mold Remediation in Schools and Commercial Buildings, at www.epa.gov/iaq/molds/mold_remediation.html.
- I am very concerned about mold in my children’s school and how it affects their health. If you believe your children are ill because of exposure to mold in their school, first consult their health care provider to determine the appropriate medical action to take. Contact the school’s administration to express your concern and to ask that they remove the mold and prevent future mold growth. If needed, you could also contact the local school board.
Questions about the Health Effects of Household Mold?
The U.S. Centers for Disease Control (CDC) has answers. For more, contact us with questions about how the law protects you.
A Dry House Equals a Healthy House
When moving isn’t an option, the quickest solution is to rid your house of moisture.
The U.S. EPA recommends action:
- If mold is a problem in your home, you need to clean up the mold and eliminate sources of moisture.
- Wash mold off hard surfaces and dry completely. Absorbent materials, such as ceiling tiles, drywall and carpet, may have to be replaced if they are contaminated with mold.
- Fix leaky plumbing or other sources of water.
- Keep drip pans in your air conditioner, refrigerator and dehumidifier clean and dry.
- Use exhaust fans or open windows in kitchens and bathrooms when showering, cooking or using the dishwasher.
- Vent clothes dryers to the outside.
- Maintain low indoor humidity, ideally between 30-50% relative humidity. Humidity levels can be measured by hygrometers, which are available at local hardware stores.
Banish Mold Step-By-Step
The DiY Network’s "Combating Household Mold" explains how to banish toxic mold: