the wood can eventually warp and an exhaust fan while cooking or taking Indoor moisture problems occur in all cause walls to crack or become a shower). climates throughout the United States structurally weak. and Canada. Common symptoms are Moisture can also be a problem during mold, mildew and condensation. This How Does Mold Become A warm weather. Cold spots can be fact sheet provides information to Problem In My Home? created when running air conditioning people who have experienced moisture Many molds flourish in common systems. When humid air comes into problems in their home and presents building materials at temperatures contact with the cold spot, condensation the health concerns related to mold humans find comfortable. Therefore, and mold growth may result. exposure. It also provides general mold can thrive and multiply indoors if guidelines on mold detection, cleanup, there is moisture available. The Important Note: and removal of mold contaminated following are sources of indoor moisture Moisture is a by-product of combustion. materials. that may cause problems: If you see moisture condensation on ¥ flooding windows or walls, you may have a Mold: What Is It? ¥ backed-up sewer combustion problem in your home. It is Molds (also known as mildew or fungi) ¥ leaky roof important to have sufficient air available are simple, microscopic organisms, ¥ cooking, bathing and other interior for fuel-burning appliances (such as the found virtually everywhere, indoors and moisture (humidity) sources such furnace, water heater, stove/range, outdoors. as watering plants or wet clothes dryer and fireplace). A shortage of air For mold to grow, it needs: hung on indoor drying lines for these appliances can result in back ¥ a location with a suitable ¥ humidifiers drafting of dangerous gasses (such as temperature range ¥ mud or ice dams carbon monoxide) and moisture into ¥ a source of moisture ¥ damp basement or crawl space the home. Contact your local utility ¥ a food source - such as leaves, ¥ constant plumbing leaks company or a professional heating wood, paper and other building ¥ moisture not exhausted from contractor to inspect your fuel-burning materials. combustion appliances. appliances.
Mold reproduction may occur through How Do High Indoor Humidity Or Health Effects Of Mold dispersal of mold spores which are very Moisture Levels Encourage Mold tiny and lightweight, allowing them to Growth? How Am I Exposed To Indoor travel through the air. Mold growths Liquid water can be squeezed Molds? can often be seen in the form of (condensed) out of air when the air Mold is found everywhere, indoors and discoloration, ranging in color from comes near a cool surface (just like the outdoors. It is common to find mold white to orange and from green to water droplets that form on a glass of spores in the air of homes. Mold brown to black. ice water on a humid summer day). spores primarily cause health problems This is most likely to happen when the when they enter the air and are inhaled Should I Be Concerned About air is humid (higher relative humidity) or in large numbers. People can also be Mold In My Home? when the surface is cold. Condensation exposed to mold through skin contact Yes, mold becomes a concern when may be the most common cause of and eating. the contamination is extensive. When moisture problems in buildings. airborne mold particles and spores are How Much Mold Does It Take To present in large numbers and inhaled, When it is cold outside, condensation Make Me Sick? they can cause allergic reactions, can form on cool indoor surfaces such It depends. For some people a asthma episodes, infections, and other as exterior walls and concrete floors relatively small number of mold spores respiratory problems. Also, exposure to (even under carpeting) causing can cause health problems. For other high spore levels can cause the unwanted mold growth. Moisture people, it may take many more. The development of an allergy to the mold problems and mold growth can be basic rule is, "if you can see it or smell leading to allergic reactions. prevented by keeping interior surfaces it" take steps to eliminate the excess Mold can also cause structural damage from becoming cold (by increasing moisture and cleanup and remove the to your home by weakening the wood insulation) or by lowering indoor mold. frame. In addition, when wood goes humidity levels by controlling ventilation through periods of wetting then drying, and moisture sources (such as running Who Is At Greater Risk When even after the molds are killed with outdoor air sample becomes the Exposed To Mold? cleaning solutions. Mycotoxins have reference by which the indoor air Exposure to mold is not healthy for been found in agricultural settings, in samples are measured against. anyone inside buildings. It is important food, and indoor spaces of homes and to quickly identify and correct any office buildings. Health effects moisture sources before health observed in humans vary with the specific toxin, the amount of exposure, problems develop. The following Solving Moisture Problems individuals appear to be at higher risk and the route of exposure. for adverse health effects of molds: And Reoccurrence Of Mold ¥ infants and children Detection Of Mold ¥ elderly Unless the source of moisture is removed and the contaminated area is ¥ immune compromised patients How Can I Tell If I Have Mold In (people with HIV infection, cancer properly cleaned, mold growth will My House? reoccur. chemotherapy, liver disease) If you can see mold or if there is an ¥ pregnant women earthy or musty odor, you can assume ¥ Identify and correct the moisture ¥ individuals with existing respiratory that you have a mold problem. Allergic conditions or sensitivities such as source individuals may have the symptoms ¥ Clean, and thoroughly dry the allergies, multiple chemical listed above. Look for previous water sensitivity, and asthma. moldy area (sanitize only if damage, especially on porous necessary) materials. Visible mold growth often is ¥ Bag and dispose of any material People with these special concerns found underneath materials where should consult a physician if they are that has moldy residues, such as water has damaged surfaces or behind rags, paper, leaves, or debris. having health problems. walls. Look for discoloration and leaching from plaster. What Symptoms Are Common? Allergic reactions may be the most Should I Test My Home For Mold? common health problem of mold It is not recommended to perform exposure. Typical symptoms (alone or testing as the first step to determine if in combination) reported by people you have a mold problem. Mold exposed to mold include: sampling can be expensive. If you can ¥ respiratory problems see or smell mold, you have a moisture ¥ nasal and sinus congestion and mold problem. Cleanup and ¥ dry, hacking cough removal procedures are discussed ¥ wheezing, and difficulty in breathing below. ¥ sore throat ¥ shortness of breath Airborne mold assessment requires ¥ eyes - burning, watery, reddened, sampling equipment not available to the blurry vision, light sensitivity general public. Standard assessment ¥ skin irritation methods will vary depending on the ¥ central nervous system problems type of material sampled. If sampling is (constant headaches, memory done, normally a combination of source problems, mood changes). samples (carpet dust, discolored sheetrock) and airborne samples is Are Some Molds More Hazardous recommended. Currently, there are no Than Others? air standards for levels of mold indoors. Yes. Allergic individuals vary in their An outdoor air reference sample must sensitivities to mold, both in amount always be taken at the same time that and type needed to cause reactions. In indoor air samples are taken. This addition, certain molds produce toxins, called mycotoxins, that the mold uses to inhibit or prevent the growth of other organisms. Exposure to mycotoxins may present a greater hazard to occupants than that of allergenic or irritative molds. Mycotoxins and allergens are found in both living and dead molds and spores. Therefore, moldy materials need to be removed, ¥ Cold surfaces: A modest How Do I Clean And Sanitize increase in indoor temperatures Mold In My Home? can reduce condensation on cold surfaces. Turning up Clean surfaces: thermostats, opening doors to ¥ You must first clean the closets on exterior walls, contaminated area to remove opening heating grilles in existing mold. Identify And Correct Moisture unused rooms and adding ¥ Use a non-ammonia soap/ Problems insulation in walls and ceilings detergent or a commercial Identify and remove the source of can help raise surface cleaner in hot water. moisture. After the moisture source has temperatures during cold ¥ Thoroughly scrub all been corrected, begin the cleanup and weather. Re-directing cold air contaminated surfaces (use a drying out process. from air conditioning units away stiff brush to clean block walls from walls and other objects and other semi-porous You can usually control a moisture during warm, humid weather surfaces) with the problem by correcting water leaks (such can also help reduce soap/detergent. It is best to a plumbing or roofing problems), condensation. use an excessive amount of reducing indoor air moisture levels or ¥ Flooding: Wait for water to cleaning solution for this step. increasing indoor surface temperatures recede, then begin cleanup and ¥ Rinse clean with water. You (to limit condensation problems). drying out process. can use a wet-dry vacuum to collect excess water. Correcting common problems: Cleanup And Removal ¥ Water leaks: Repair constant Of Mold Never mix bleach with ammonia -- the plumbing leaks no matter how fumes are toxic. small. Exterior soil, walkways What Can I Save? What Can I Wear eye protection & rubber gloves. and driveways should be Ventilate the working area well graded away from the house to Toss? prevent water from running into In this situation, use your best Sanitize surfaces: Consider the use of or puddling near the house judgement. If the material absorbs a biocide or sanitizing solution only if foundation. Roof leaks should water, it is considered porous. Porous cleaning did not completely remove the be repaired immediately. Also, materials should be thrown out if mold and mold spores, and removal of cleaning gutters and canales in exposed to long periods of dampness. the material was not possible. the fall after leaves have fallen Semi-porous material (such as wood ¥ After cleaning, apply sanitizing can help prevent mud and ice framing, trim, and furniture) may be solution of 3/4-cup household dams from forming. salvaged if mold contamination has not bleach per gallon of water to ¥ High indoor humidity: Source penetrated the material too deeply or the surface. If the mold has control is often the most affected its structural integrity. Semi- already started to grow back, effective method of reducing porous and non-porous materials (such try a stronger solution - 1-1/2 indoor humidity and moisture. as hard plastic, glass, and metal) can cup of bleach per gallon of Common source control be cleaned and, if necessary, sanitized water. Using bleach straight methods include: venting with a dilute biocide solution. from the bottle will not be more bathrooms, kitchen stoves, effective. Bleach solution can clothes dryers, space heaters Removal Of Moldy Materials be applied to large areas with a to the outdoors; removing Using precautions to avoid mold handheld garden sprayer. In unvented kerosene or gas exposure, remove and throw out porous case of flooding, be sure to space heaters; maintaining dry materials (example: ceiling tiles, thoroughly wet the studs, wall basements and crawlspaces; sheetrock, plaster, wood products, cavities, and floors. Avoid and storing firewood outdoors. carpet/carpet pad) and begin drying out excessive run off. Use wet-dry Exhaust fans can be used to the area within 24 to 48 hours. Bag and vacuum to collect extra bleach remove moisture from cooking, discard moldy materials. If flooding solution. Allow the bleach bathing, or laundering. Dilution occurred, remove and replace all solution to dry naturally for a of moist indoor air is also a sheetrock and insulation damaged by 6 to 8 hour period. The useful method of moisture water up to at least 12 inches above bleach solution should not be control. If outside air is more the high water mark. You will need to removed or dried quickly, humid than indoor air or if visually inspect to see if you need to extended contact time is increased ventilation is not an remove more than the 12 inches above important. option, consider using the high water mark. refrigerated air conditioning or a stand-alone dehumidifier. NOTE: Bleach can irritate your eyes, your home's air duct system has had Can Ozone Air Cleaners Help nose and throat. Ventilate the water damage, first identify the type of Remove Indoor Mold? working area well. air duct construction that you have. Some air cleaners are designed to Bare sheet metal systems or sheet produce ozone. Ozone is a strong Dry Surfaces: metal with exterior fibrous glass oxidizing agent used as a sanitizer and ¥ If flooding occurred, thoroughly insulation can be cleaned and sanitized. to eliminate odors. However, ozone is dry out the affected area using a known lung irritant. Symptoms fans and dehumidifiers. Be If your system has sheet metal with an associated with exposure include patient -- allow six weeks or internal fibrous glass liner or is made cough, chest pain, and eye, nose, and more for the drying process entirely of fibrous glass, the ductwork throat irritation. Although there are no before installing new building normally will need to be discarded. air standards for ozone production from materials (carpet, paint, sheet- Underground air ductwork systems may air cleaners, some ozone generators rock). Also, allow inside of need to be abandoned. If you have have been shown to generate indoor walls to dry thoroughly. other questions, contact an air duct ozone levels above standards set for cleaning professional. other purposes. A recent study by the Can Cleaning Up Mold Be U.S. Environmental Protection Agency Hazardous To My Health? After I've Cleaned Everything As (EPA) demonstrated that ozone is not Yes. Exposure to mold can occur Thoroughly As Possible, Can I effective for killing airborne molds and during the cleaning stage. Mold counts Still Have Odors? fungi even at high concentrations (6 to in the air are typically 10 to 1,000 times Yes. It is very possible that odors will 9 parts per million).* Health experts higher than background levels during persist. Continue to dry out the area caution against introducing a lung the cleaning of mold-damaged and search for any hidden sources of irritant directly into an indoor materials. Take steps to protect your mold. Do not assume that if you've environment. For these reasons, you health during cleanup. Consider cleaned the front side of a moldy are strongly discouraged from using using an N95 particulate respirator surface that the backside is not moldy. ozone air cleaners in any occupied (sometimes referred to as the TC-21C Mold often grows under cabinets, inside residential space. particulate respirator), approved by the walls (insulation), in carpet padding, National Institute for Occupational and under vinyl wall coverings. You will *U.S. Environmental Protection Agency. Safety and Health, and wear clothing have to be on "Mold Alert". Be Ozone generators in indoor air settings. that can be laundered or discarded particularly careful about moisture U.S. EPA Report, EPA-600/R-95-154 afterward. Wear rubber gloves and eye which could trigger mold growth. If the (NTIS PB96-100201), October 1995. protection. Respirators can be area continues to smell musty, you may purchased at safety supply stores or have to clean the area again (follow the Questions? some hardware and building supply cleaning steps given in this fact sheet). Contact your local or state health stores may carry them. Ask family Continue to dry and ventilate the area. department or local American Lung members, especially children and the Don't replace flooring or begin Association office. elderly to leave areas being cleaned. rebuilding until the area has dried Consider cleaning a small test patch of completely. This fact sheet has been created for the mold first. If you feel that this is H.E.L.P. for Kids Project. adversely affecting your health, you What Kinds Of Moisture Clues may wish to pay a licensed contractor Could Appear In My Home This Portions of this document have been or professional to carry out the work. Winter That May Lead to Further reprinted with permission from "Mold in My Home: Is Mold a Health Concern?" Moisture Damage? Never use a gasoline engine, created by the Minnesota Department ¥ window condensation powered pressure washer, of Health Indoor Air Program. For an ¥ plasterboard cracking generator, or space heater indoors -- excellent article on moisture problems ¥ drywall tape loosening and you could be exposing yourself and in homes see "Fundamentals of boards and wood warping your family to carbon monoxide. Moisture in Houses" by Joseph ¥ musty odor Lstiburek and John Carmody, Home If you see any of the above, seek out Energy, Vol. 12, No. 6. Can Air Duct Systems Become and take steps to eliminate sources of Contaminated With Mold? moisture as quickly as possible. Keep Yes. Air duct systems can become surfaces dry and the relative humidity contaminated with mold. Air duct between 20 and 40 percent in the systems can be constructed of bare winter season and less than 60 percent sheet metal, sheet metal with an the rest of the year. Look for exterior fibrous glass insulation, sheet appearance of mold on surfaces. metal with an internal fibrous glass liner or made of entirely fibrous glass. If