Seattle Home Inspector's Blog


Moldy crap Batman---those are some incredible claims!

The other day I read a post here in the rain that would have us believe that mold can cause bleeding lungs, cancer, ameobiasis, cholera and even typhoid fever.

Mold or mold-like fungal growth on a basement wallAs I read through the list I thought, “Holy crap---those are some incredible claims!”

I can be a pretty skeptical person, and if there is anything I have learned over my lifetime, it is that if things don’t smell right they probably don’t taste very good either.  An interesting thing about the word “incredible” is that it easily can be interpreted as “not credible.”

Let’s face it----if these claims are true (or even mostly true) the planet is in a world of hurt and it is actually is not safe to live anywhere.

I decided I would do a little research to see if the claims were true---and to what degree.  I wanted to find out if there is any science behind the claims or is it just hysteria-inducing rhetoric designed to line someone’s pockets.  One of the first things I discovered in doing a Google search for the items on the list brought up the very articles posted on activerain making the claims.  Finding something “authoritative” took a little more digging.

1.      Let’s look at the first claim, that mold can cause bleeding lungs.  According to the Center for Disease Control“In 1994 and 1997, CDC reported clusters of acute pulmonary hemorrhage in infants. Reviews by internal CDC and external expert panels of these investigations identified shortcomings in the conduct of the studies. The panels concluded that the investigations did not prove an association between acute pulmonary hemorrhage in infants and exposure to molds, specifically Stachybotrys chartarum (atra)”.

The CDC decided to undertake studies to follow the possibility further.  Until these studies are published I think it is grossly irresponsible to claim that anecdotal information related to bleeding lungs in infants (and then extrapolated to adults) should be seen as “proof” that mold causes bleeding lungs.

2.      The second claim would have us believe that mold can cause cancer. This claim comes from the fact that there are mycotoxins given off from molds that can cause cancer.  The fact that one is more likely to come in contact with these toxins in the food we eat than in the air we breathe does not stop some people from using the data to suit their needs.  Aflatoxin, found in field corn and peanuts is one such toxin.  Under certain environmental conditions molds can give off toxins that are known to be harmful to humans.  However, according to Wikipedia, “such exposures rarely to never occur in normal exposure scenarios, even in residences with serious mold problems.”  Wikipedia goes on to say that, “the so-called toxic effects are actually the result of chronic activation of the immune system, leading to chronic inflammation.”

In other words your body is telling you there is crud in the air----do something about it---get me out of here.  It is estimated that 25% of the population is genetically pre-disposed to react negatively to mold.  Of that 25 percent---only 2% will react “negatively” to that mold condition.

 98% of the population is unreasonably scared to death of “mold” due to media hysteria and misinformation.

Immunocompromised people (transplant patients, aids patients etc) are always going to be more vulnerable to exposure to molds.  If you are already harboring fungal infections, you increase the chances that you will react badly to the presence of mold.  This says more about us than mold however.

3.      Next let’s look at the claim that mold can cause ameobiasis.  The closest I could get to a connection here is that if you were treated for one of the amoeba caused diseases such as dysentery and all your good intestinal flora was killed off you would certainly be more susceptible to other fungal growths in your body.  Again this would seem to be something pretty remote in relation to indoor air quality. Given the overuse of antibiotics in this country it should be no surprise to anyone that some individuals will be more susceptible to fungal infections.

4.      Cholera?  Rats---I knew this one was going to be hard.  According to the World Health Organization, “Cholera is an acute intestinal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. It…….causes a copious, painless, watery diarrhoea that can quickly lead to severe dehydration and death if treatment is not promptly given. Vomiting also occurs in most patients.”  I suppose if you go to a third world country and come home with dysentery and weaken your immune system to the point that you are vulnerable to fungal infection, mold “might” become a factor.  To include it in a routine list of things that can be caused by mold in the indoor environment seems a bit of a stretch.

5.      So what about the last one on the list, Typhoid Fever?  This one is the coolest find of all---and by far the hardest one to get my brain around.  But the connection between mold and Typhoid Fever was obvious.  It was the first disease to be cured by a mold----Penicillin.  Again, as almost anyone knows that has taken antibiotics, if you kill off all the good bacteria in your bodies you are naturally going to leave yourself more vulnerable to fungal infections---even Athletes Foot and Candida.  Again, how this relates to indoor air quality in the average home I find baffling.


As a way to put this all in perspective we have this quote from Dampness and Mould by the World Health Organization:  There is strong evidence regarding the hazards posed by several biological agents that pollute indoor air; however, the WHO working group convened in October 2006 concluded that the individual species of microbes and other biological agents that are responsible for health effects cannot be identified. This is due to the fact that people are often exposed to multiple agents simultaneously, to complexities in accurately estimating exposure and to the large numbers of symptoms and health outcomes due to exposure. The exceptions include some common allergies, which can be attributed to specific agents, such as house-dust mites and pets.

The presence of many biological agents in the indoor environment is due to dampness and inadequate ventilation. Excess moisture on almost all indoor materials leads to growth of microbes, such as mould, fungi and bacteria, which subsequently emit spores, cells, fragments and volatile organic compounds into indoor air. Moreover, dampness initiates chemical or biological degradation of materials, which also pollutes indoor air. Dampness has therefore been suggested to be a strong, consistent indicator of risk of asthma and respiratory symptoms (e.g. cough and wheeze). The health risks of biological contaminants of indoor air could thus be addressed by considering dampness as the risk indicator.

The underlining is mine and to repeat:  Dampness as the risk indicator.


Charles Buell, Seattle Home Inspector


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Comment balloon 43 commentsCharles Buell • February 25 2011 01:03PM
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