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How do I know if my place is safe?

(and who’s faster, Garfield or a tiger?)

Hazardous indoor mold has been around for a long time.  And so has the question of whether your place is safe. In fact, the first Mold Inspection and remediation protocol that I’m aware of is from about 3300 years ago in the Book of Leviticus.  More recently I’ve never heard of a priest taking on that job.  It seems to fall to mold inspectors and remediators now.  Like anyone else they can look everywhere with a flash light and ask “Do I see or smell mold?”  Similarly they know that mold comes from water damage and so they look everywhere for evidence of water intrusion. Water damage doesn’t guarantee mold but if it’s not cleaned up within 48 hours the odd of mold are quite high. In fact nearly 50% of all buildings have a history of water damage. (1,2, 3)

But wouldn’t it be nice to have a more objective test?

Welcome mold spore trapping.  The idea behind mold spore trapping is that while we may not be able to see the individual mold spore particles in the air we could trap them in cassettes and measure them that way.  The way it works is that tiny plastic traps allow the air to pass through them but in the middle is a slide with adhesive on it. The mold spores fall onto the adhesive and stick. Then you take the slide out of the spore trap and look at the spores under the microscope and try to figure out what they are and how many.

To date there have never been any specific  standards for how many spores are safe for our health,  but the idea is that you can compare the outside to the inside and if inside is a lot more that’s not a good sign,,  Further you can compare room to room and that might help the remediator do his job. . Mold inspectors use this all the time and I don’t begrudge them their right to do but is it always the best test for someone who’s really sensitive to mold to know the place is safe?

First of all, spore counts can vary from day to day depending on activity in the room and how much dust is kicked up by traffic.  Experts in the field estimate that you’d have to test anywhere from 3-9 times per room to get a more accurate estimate of the spores in the air (4)

Further, some particles more easily get kicked up into the air and other don’t.  Stachybotrys the notorious black mold could be thought of as “Sicky-botys” because it inherently clings to surfaces more tightly so it might get missed on a spore trap count when it’s there but it could still become airborne anytime and cause big problems.

Similarly concerning is that fact that under the microscope you might be able to tell what genus the mold is but you can’t tell the species.  In some cases species of similar sized mold like Aspergillus and Penicillium are actually lumped together in the report as they can be hard to distinguish under the microscope.

It turns out through that different species of molds are associated with different levels of mycotoxins that impact people’s health.  So to get a better estimate of safety for the health of the most sensitive we want to know down the species level. If you were challenged to a running match with a cat it might make difference if it were Garfield or a Jaguar.  If you had a play day with your kids and a cat it might make difference it where a Tiger or Persian Kitten.  For someone knowing the species can matter.

How can we do that?  With the same testing that dramatically changed the forensic world: DNA. In 2006 the EPA introduced the Environmental Relative Moldiness Index (ERMI) which is a quantitative test of the DNA of various Mold species. Shoemaker used that and found it correlated well with what type of dwelling was safe for people with biotoxin mold illness a.k.a Chronic Inflammatory Response Syndrome (CIRS).  He then created a subset of that data called the Health Effects Roster of Type Specific (Formers) of Mycotoxins and Inflammagens, Version 2 (HERTSMI 2).  Air spore trap results have never been correlated with health outcomes in anyone.  Both of these DNA test have now been validated to health outcomes (5). No test is perfect, but these tests are where we start.

Home kits can be purchased from either or In most instances we get the HERTSMI 2 as it’s cheaper.  There are two collection methods , the vacuum method and the Swiffer cloth method. Usually the Swiffer cloth method is preferred unless you have wall to wall carpeting, and no pets.  Further, we like a great IEP in the Midwest, Larry Schwartz of Safe Start, who has some further instructions on collecting a good sample. (6)

Do you even need to do this test?  If you’re suspicious that you’re particularly sensitive to mold and that your home may have it, it seems reasonable.  You could also get the Visual Contrast Test online at You’ll take a symptom survey and do a test that often picks up the effects of neurotoxins on the brain.  And, of course, you could come see us and discuss the situation.

All that glitters is not gold and all that hurts you is not mold, but if mold is hurting you, and if your place isn’t safe, you want to know.