How to interpret mold results?

November 13, 2010 11:23 AM

Help! New home may have mold - technical details enclosed.

We are looking at a bank-owned property in Charleston, SC. It has been sitting unoccupied for 2 years with no HVAC running. Naturally there is some mold.

We are wondering if the results are worth making a big deal about. the home is significantly less than comps in the area.

Can anyone help determine what the health or other effects of these results are?


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posted by toastchee to home & garden (4 answers total)

Word on the street is that certain kinds of mold, namely "black mold" can cause serious health problems if it becomes airborne and is inhaled. I have had some luck personally with bleach spray in mitigating the effects of the mold, at least on visible surfaces, but I highly recommend you speak to a professional, because it can be dangerous. When I signed the lease for the last apartment I rented, I had to sign a waiver specifically related to mold. So it is serious.
posted by Astragalus at 11:56 AM on November 13, 2010

Unfortunately, this mold report sucks, because it doesn't tell you what molds are of potential concern and whether or not you should worry about the quantities found, which means you'll have to do some detective work.

Let's see. The best way to read this mold report is to look up the mold species it finds and see what it says about them. For example:

Cladosporium spp: Very common, does not produce toxins, but can be an allergen.
Ascospores: Spores from ascomycota species. This is a big group, so without more specificity it's hard to say much about them.
Aspergillum/penicillum: A mostly harmless group with a few toxic members that cause disease. It's hard to say which are in the house -- this could be no issue at all or a major issue.

Feel free to look up the rest on wikipedia.

Ideally, you would want to repeat this test outside your home for a baseline comparison. If you have more or less the same variety of species indoors as outdoors, it really shouldn't be an issue, but I'm going to go ahead and guess that the levels inside really are worse than outside.

I think you need to talk to an expert here. I would call a mold removal company in your area and ask them about the mold species found and their levels to see if anything is of concern. Since, of course, they are selling their services, you might try calling a few to see if you can get a consensus opinion.

If they say there's a problem, I would listen to their advice. If it's a relatively mild issue that they feel confident they can eradicate, ok. If levels are well above what they should be, I would walk.
posted by zug at 12:58 PM on November 13, 2010

I will summarize a report I got from a mold company. I'm not an expert and don't know what these concentrations indicate.

Generally, mold's impacts vary based on a person's immune system. Babies, people with low immune systems, pregnant women, and the elderly have greater risk. There are three kinds of health impacts: allergic reactions, toxic or carcinogenic effects, and infection (e.g., the mold growing in your sinuses, rare in healthy individuals). Without water, molds don't grow, so this may be telling you something about the water tightness of the house.

- Ascospores: a broad category. The bad ones are usually counted separately, so "ascospores" seems to mean "spores with a sac-like structure that were too unimportant to be identified individually."

- Aspergillus: primarily an allergen. There are approximately 200 species, and it can't generally be discerned from Pencillium, also an allergen though also occasionally with toxin or infectious properties. Different species have different health effects. Many are allergenic; some produce toxins. Aspergillus is one of the most infectious of molds (but again, this rarely affects the healthy).

- Basidiospores: a general class of spore formed on a structure known as a basidium (from rusts, smuts and mushrooms). Common in outdoor air samples, might indicate dry rot, water damage, or just high humidity. Many are allergenic.

- Bipolaris: found in the soil. It is allergenic and the most common agent for allergic fungal sinusitis. It can also uncommonly cause infections of the eye, nose, lungs and skin.

- Cladosporum: the most common mold in outdoor air by far. Indoor concentrations are usually not as high. It is an important allergen and commonly gives symptoms of hay fever, asthma, and other allergies. Extremely chronic exposure may lead to emphysema.

- Curvularia: my report doesn't have much info on this. Allergenic, can cause infections in immunocompromised individuals.

- Pithomyces: associated with decaying plants, leaves, and grasses. Sounds fairly harmless to my non-expert self. Not allergenic or infectious, though some species produce a toxin that give sheep facial eczema. (So keep your sheep from touching it, okay?) Not commonly found indoors. But it is important because, to some extent, it indicates the presence of conditions that would also support some of the more unhealthy molds.

- Smut / Myxomycete: another general category for common types that are not really health concerns, though some are mildly allergenic. Associated with living and decaying plants as well as decaying wood.

- Ulocladium: a major allergen, requires more water than some other molds.

- I don't have info on the others (Nigro~, Pesta~, and Poly~).

I'll leave it to you to cross-reference this with the reports you received, but the upstairs right bedroom stands out to me. You don't have many molds I had, which were associated with standing water, and you don't have the "toxic black mold" (Stachybotrys chartarum). You do have two species that indicate conditions might be approaching what it takes to grow, however (Pithomyces and Ulocladium).

Unrequested Advice Alert: In your shoes, I'd try to understand what this means not just for ongoing health effects but also for short-term repair costs. Mold needs water to grow, and so the more you solve water intrusion problems, the less mold you'll have. Is there visible mold? If not, is it within the walls? If so, is there ongoing water intrusion? If so, what will it take to stop it? Is there a known source that can easily be fixed, or will it take a lengthy investigation to figure out what pipe is leaking? If the intrusion happened in a one-time event, is this nevertheless enough to require opening up the walls to eliminate the mold?
posted by slidell at 12:58 PM on November 13, 2010

and by "same variety of species indoors as outdoors", I of course mean not only the species but the *relative quantities* of those species, as that will indicate if they are growing out of control inside the home.
posted by zug at 12:59 PM on November 13, 2010