ANSWER: It depends on the situation and the person. This question is difficult to answer in the same way it’s hard to say how much sun causes a sunburn: the amount varies from person to person. What one person can tolerate with little or no effect may cause symptoms in another individual.
The long-term presence of indoor mold may eventually become unhealthy for anyone. Those with special health concerns should consult a medical doctor if they feel their health is affected by indoor mold. The following types of people may be affected sooner and more severely than others:
- Babies and children
- Elderly persons
- Individuals with chronic respiratory conditions or allergies or asthma
- Persons having weakened immune systems (for example, people with HIV or AIDS, chemotherapy patients, or organ transplant recipients)
ANSWER: Indoor mold growth can usually be seen or smelled. In most cases, if visible mold growth is present, sampling is not needed. There are no health or exposure-based standards that you can use to evaluate a mold sampling result. The Florida Department of Health does not recommend mold testing or sampling to see if you have a mold problem, or to see what kind of mold might be growing. Sampling for mold in the air can be expensive and, if done, should only be done by experienced professionals. Investigate a mold problem; don’t test.
- Look for visible mold growth (it may look cottony, velvety, rough, or leathery and have different colors like white, gray, brown, black, yellow, or green). Mold often appears as a staining or fuzzy growth on furniture or building materials (walls, ceilings, or anything made of wood or paper). Look for signs of moisture or water damage (water leaks, standing water, water stains, condensation, etc.).
- Check around air handling units (air conditioners, furnaces) for standing water. Routinely inspect the evaporator coils, liner surfaces, drain pans and drain lines.
- Search areas where you notice mold odors. If you can smell an earthy or musty odor, you may have a mold problem.
- If mold-allergic people have some of the symptoms listed above when in your home, you may have a mold problem.
ANSWER: Some types of molds can produce chemicals called “mycotoxins”. These molds are common, and are sometimes referred to as “toxic mold”. There are very few reports that “toxic molds” inside homes can cause unique or rare health conditions. If you think you have a mold problem in your home, you do not need to find out what type of mold you may have. All molds should be treated the same when it comes to health risks and removal. All indoor mold growth should be removed promptly, no matter what type(s) of mold is present, or whether or not it can produce mycotoxins.
Stachybotrys chartarum (also known as Stachybotrys atra) is a greenish-black mold that can grow on materials such as drywall or sheetrock, ceiling tiles and wood when they become moist or water-damaged. Not all greenish-black molds are Stachybotrys chartarum. Some strains of Stachybotrys chartarum may produce mycotoxins. Whether a mold produces mycotoxins depends on what the mold is growing on and conditions such as temperature, pH, humidity or other factors. When mycotoxins are present, they occur in both living and dead mold spores, and may be present in materials that have become contaminated with molds. While Stachybotrys is growing, a wet slime layer covers its spores, preventing them from becoming airborne. When the mold dies and dries up, air currents or physical handling can cause spores to become airborne.
Currently, there is no test to determine whether Stachybotrys growth found in buildings is producing toxins. There is also no blood or urine test that can tell if an individual has been exposed to Stachybotrys chartarum spores or its toxins.
Typically, indoor air levels of Stachybotrys are low. As with other types of mold, at higher levels adverse health effects may occur. These include cold-like symptoms, rashes, sinus inflammation, eye irritation and aggravation of asthma. Some symptoms are more general – such as inability to concentrate or fatigue. Usually, symptoms disappear after the mold is removed.
Many molds are black but are not Stachybotrys. For example, the black mold often found between bathroom tiles is not Stachybotrys. Stachybotrys can be identified only by specially trained professionals through a microscopic exam or by cultures. The Florida Department of Health does not recommend that people sample mold growth in their home. All indoor mold growth should be removed, regardless of type.
Water is the key. Without it, mold growth cannot start, much less multiply and spread. The easiest way to prevent the mold from gaining a foothold is to control dampness. Keep your home clean and dry. When water stands for even 24 hours, common molds can take hold. Keeping humidity levels below 60% and venting moisture from showering and cooking to the outside are several ways to prevent the conditions that can lead to mold growth. Other ways include:
- Clean and dry up spills within 24 hours
- Dry out wet building materials and carpets within 24 hours
- Use an air conditioner or a dehumidifier to reduce the indoor humidity levels below 60%. If you have a central air conditioning system and need a dehumidifier to reduce relative humidity below 60%, you should have the air conditioning system examined for problems
- Do not carpet bathrooms or basements
Note: While most experts suggest a relative humidity of less than 60%, below 50% is best for controlling both mold growth and dust mites. Dust mites are microscopic animals related to spiders, ticks and other mites. Dust mites eat mold and dead human or animal skin scales (flakes) and leave allergenic proteins. Dust mites reduce allergen production at these lower humidity levels.
Mold should be cleaned as soon as it appears. Persons who clean the mold should be free of symptoms and allergies. Small areas of mold should be cleaned using a detergent/soapy water or a commercial mildew or mold cleaner. Gloves and goggles should be worn during cleaning. The cleaned area should then be thoroughly dried. Throw away any sponges or rags used to clean mold.
If the mold returns quickly or spreads, it may mean you have an underlying problem, such as a water leak. Any water leaks must first be fixed when solving mold problems. If there is a lot of mold growth, consult the U.S. Environmental Protection Agency’s booklet: “Mold Remediation in Schools and Commercial Buildings”. If the moldy material is not easily cleanable, such as drywall, carpet padding and insulation, then removal and replacement may be necessary.
Using bleach or other chemicals to kill indoor mold growth is not needed in most cases. The goal should be to remove mold growth by cleaning or removing moldy materials. Dead mold can still pose health risks if you are exposed. Using bleach or other disinfectants on surfaces after mold removal may be needed where people are thought to be susceptible to fungal infections (such as a person with immune system problems). Should you decide to use bleach or another chemical, please read and carefully follow the label directions and hazard statements (caution, warning, danger). Do not mix bleach with ammonia cleaners or acids, because a dangerous chlorine gas may be formed.
Mold is virtually everywhere, floating in the air and on all surfaces. People are exposed to molds 24 hours a day, seven days a week, and 365 days a year. Exposures increase when indoor moldy materials becomes dried, damaged or disturbed, causing spores and other mold cells to be released into the air and then inhaled. Elevated exposure can also occur if people directly handle moldy materials or accidentally eat mold.
No. Ozone irritates lungs, and is not likely to be effective at addressing an indoor mold problem. No one should expose themselves or others to ozone on purpose. Address the cause of the mold (usually moisture) and then remove the mold by cleaning surfaces or removing moldy materials.
The Florida Department of Health Indoor Air program helps with mold issues through the following activities:
- Providing technical assistance and advice to the public, County Health Departments, School Districts and others
- Distributing current information and other resources on mold and moisture control
The composite materials that are used today have adhesives that can be digested by fungi we call molds. Mold will also digest sugars and starches in wood fiber, if the cell walls have been crushed or broken. Solid lumber has intact cell walls that cannot be enetrated by molds. Molds will grow on the surface, but the wood will retain its structural strength. Particle board, oriented-strand board (OSB a.k.a. waferboard), and medium-density fiberboard, as well as paper-covered gypsum board, are full of adhesives, which make them good “mold chow.” Adhesives are used throughout these materials to give them form and to hold together the crushed, pulverized, or torn wood fragments or particles that make up the board. Mold digests the adhesives, and mold hyphae penetrate the resulting cracks and holes between wood particles. Structural integrity is eaten away, and so is the wall.
Mold consists of filamentous, microscopic cells called hyphae (collectively called mycelia), and asexually produced spores, which give mold colonies their powdery look. Enzymes released from the fungal cells and absorbed by the fungus as nutrients digest the organic materials in which hyphae grow. This process is what we know as decay, an essential ecological process, causing the deterioration of foods, textiles, and structural materials. For fungi, the largest part of the organisms usually remains hidden from the naked eye. The living body of the fungus is a web of tiny filaments called hyphae. This web, or mycelium, is usually hidden in the soil, wood, or whatever food source the fungus has connected itself to. These webs live unseen until they develop fruiting bodies, such as mushrooms, puffballs, truffles, brackets, or cups. If the mycelium produces microscopic fruiting bodies, people may never notice the fungus. Like all living organisms, fungi must digest their food before it can pass through the cell wall into the hyphae. However, fungi do not have stomachs. So, they digest the food outside their bodies by releasing enzymes into the surrounding environment. This breaks down the organic matter into a form it can then absorb. To reproduce, fungi release spores from the fruiting body. The fruiting body, called a sporocarp, releases spores into the air, and the wind carries the spores off to start the next generation.