10 Things you need to know about mold


by Arnold Mann

1. Where mold grows.

Molds grow everywhere, from the surface of Antarctic rocks to the inside windows of Soviet spacecraft. Molds are a part of nature. We are exposed to them every day. For most people molds only become a problem when they start growing indoors and the air inside a building becomes concentrated with allergenic spores and mycotoxins, the chemical toxins that some molds produce.

2. What happens when molds come indoors.

Airborne mold spores coming from outside are not generally a problem, at least not until they find a damp indoor haven ( a roof or plumbing leak, or high indoor humidity) in which to start setting up colonies and reproducing. The resulting high concentration of spores and mycotoxins is recirculated throughout the building by the HVAC system and can be a serious health problem, particularly to sensitive or allergic individuals. The elderly, infants and people who are immune compromized (people on chemotherapy, AIDS patients,etc.) are particularly at risk for mold-related health problems.

Most important is that molds need water to grow. Once a cellulose product like wood, ceiling tile, wallpaper or wallboard becomes wet, it becomes a mold food source. Without water, mold cannot survive.

3. What molds can do to your body

Molds can cause many health problems, including allergic and toxic reactions. Allergic reactions are much more common, occurring predominantly among people with a family history of allergies. Allergic reactions include: asthma attacks, chronic sinusitis and various other respiratory problems. Recent studies have also suggested that certain mycotoxin-producing molds may cause pulmonary hemorrhaging in infants and memory impairment in older children and adults. The mycotoxins appear to have toxic effects on the lungs and nervous system, though doctors are not certain exactly how the damage occurs.

Allergists tests for specific molds are not as useful as those for pollens, stinging insects, mites and pets because many molds cross-react with one another, so it is difficult for doctors to tell which mold is causing the problem. However, finding which mold you are allergic to is not as important, experts say, as getting rid of the mold, which will go a long way in helping solve the problem.

4. How to find out if mold is living in your home or office

There are numerous ways to test for mold, and no single way works all the time. If you can see mold, or if there is an earthy or musty odor, you can assume you have a mold problem. The first step is to identify the moisture source and correct it. 

Mold can grow in vast quantities behind walls, and it may not show up in air sampling, because spores may not be airborne at the time of sampling. Or some samplers cannot detect dead spores, which can also be a health threat. But, if there is mold growth in a building, a knowledgeable investigator using a good lab can usually detect it.

Before hiring a building investigator, ask about their training in indoor air, particularly in mold sampling. Ask whether they use an accredited lab, and check their references. What special training and experience have they acquired for investigating mold in buildings? How will they determine if sampling is appropriate? How many types of samples do they have experience taking? Do they use a laboratory accredited for environmental microbiology?

Test results should say whether there is evidence of mold growth in a building and what kinds of mold have been found rather than providing mold counts, which alone are useless

5. Dead mold is still dangerous

Dead molds are just as undesirable as live molds; they can still make you sick. Removing molds (dead and alive) is more important than killing them.

6. Some molds are more hazardous than others

Molds that produce mycotoxins, such as Stachybotrys and Trichoderma, present a greater hazard than common allergenic molds like Cladosporium and Alternaria. Health effects will vary with the specific toxin, the concentration in the air and the age and general health of the patient.

7. You can keep mold out

Mold growth and the illnesses associated with it can be prevented by keeping buildings and the air in them dry — ideally, indoor relative humidity should be kept below 60 percent. A dehumidifier will keep the humidity in the air low, but if it is not cleaned frequently, it can become a source of mold contamination itself. Any significant areas of mold growth found inside a building should be removed, not just killed, by trained individuals wearing proper protective clothing and equipment. The larger the area, the more caution is required.

8. Molds are useful organisms.

Together with bacteria, they are responsible for breaking down organic matter. They are among the principal micro-organisms involved in biodeterioration, which gives us compost and many other useful things.

9. Molds make up 25 percent of the biomass of the earth.

10. Molds have been causing humans grief since time began.