Fungi (Mold) Hazards
Fungi (mold) are found everywhere – both indoors and outdoors, all year round. The terms fungi and mold are often used interchangeably, but mold is a type of fungi. There are many thousands of species of mold and most, if not all, of the mold found indoors comes from outdoor sources.
Mold seems likely to grow and become a problem only when there is water damage, high humidity, or dampness. Molds are organized into three groups according to human responses:
We will take a closer look at each of these types of molds in the next section.
Molds Effect on the Body
Molds produce and release millions of spores small enough to be airborne. They can also produce toxic agents known as mycotoxins. Spores and mycotoxins can have negative effects
on human health. The most common route of entry into the body is through inhalation; mold has a characteristic smell – if you smell mold, you could be inhaling mold. Mold is generally visible; however, some of the most toxic mold spores are small enough to be considered
respirable [less than 10 micrometers (10 μm) in diameter].
Allergenic molds do not usually produce life-threatening health effects and are most likely to affect those who are already allergic or asthmatic. The human system responses to allergenic molds tend to be relatively mild, depending on individual sensitivities, typically producing scratchy throats, eye and nose irritations, and rashes.
Pathogenic molds usually produce some type of infection. They can cause serious health effects in persons with suppressed immune systems. Healthy people can usually resist infection by these organisms regardless of dose. In some cases, high exposure may cause hypersensitivity pneumonitis (an acute response to exposure to an organism).
Mycotoxins can cause serious health effects in almost anybody. These agents have toxic effects ranging from short-term irritation to immuno suppression and possibly cancer. Therefore, when toxigenic molds are found, further evaluation is recommended.
Ten Things You Should Know About Mold
- Potential health effects and symptoms associated with mold exposures include allergic reactions, asthma, and other respiratory complaints.
- There is no practical way to eliminate all molds and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.
- If mold is a problem in your workplace, you must clean up the mold and eliminate sources of moisture.
- Fix the source of the water problem or leak to prevent mold growth.
- Reduce indoor humidity (to 30-60%) to decrease mold growth.
- Clean and dry any damp or wet building materials and furnishings to prevent mold growth.
- Clean mold off hard surfaces with water and detergent, and dry completely.
- Absorbent materials, such as ceiling tiles, that are moldy may need to be replaced.
- Prevent condensation on cold surfaces by adding insulation.
- In areas where there is a perpetual moisture problem, do not install carpeting.
Remember, molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present.
There are several things to be aware of while cleaning up mold on a construction site. Here are a few things to remember.
- Non-porous materials (e.g., metal, glass, hard plastics, etc.) can be dried out, fully cleaned and reused. Clean hard and non-porous materials using a detergent. Surfaces can be rinsed with a disinfectant made of ½ cup liquid household bleach mixed into one gallon of water (Caution: DO NOT mix bleach with cleaning products that contain ammonia).
- Semi-porous materials (e.g., wood and concrete) can be cleaned if they are structurally sound.
- Porous materials (e.g., drywall, carpets, insulation, ceiling tile, etc.) are different because mold penetrates into them making it very difficult to fully clean. As a general rule, if a porous material has been wet for over 48 hours it is best to remove and replace.
CAUTION: Do not mix bleach with other cleaning products that contain ammonia. Highly toxic chlorine gas can be produced.
- Avoid breathing mold spores. A N-95 respirator is recommended.
- Avoid touching mold with your bare hands. Long gloves that extend to the middle of the forearm are recommended. Use ordinary household rubber gloves when cleaning surfaces with water, bleach, and a mild detergent. Gloves made from natural rubber, neoprene, nitrile, polyurethane, or PVC are recommended if using a disinfectant, biocide, or strong cleaning solution.
- Avoid getting mold spores in your eyes. Goggles without ventilation holes are recommended.
Respirators protect cleanup workers from inhaling airborne mold, contaminated dust, and other particulates released during the remediation process. Either a half mask or full facepiece air-purifying respirator can be used. A full-facepiece respirator provides both respiratory and eye protection. More protective respirators may have to be selected and used if toxic contaminants such as asbestos or lead are encountered during remediation.
Respiratory protection is effective only if:
- the correct respirator is used
- it’s available when you need it
- you know when and how to put it on and take it off
- you have stored it and kept it in working order in accordance with the manufacturer’s instructions
Respiratory protection for exposure to mold will depend on the size of the particle and its level of toxicity.
- Whenever you smell or see the presence of mold, it is important to take precautions to limit your exposure to mold and mold spores.
- To limit your exposure to airborne mold, you need to wear, at a minimum, an N-95 respirator.
- If oil is present in the air, make sure to use either an R or a P designed filter.