Freaquently Asked Questions

5. Do all molds affect everyone in the same manner?
The simple answer is "No. Molds affect people differently." For a more detailed answer it is helpful to examine three ways in which fungi can adversely affect a person's health. (Note that some aspects of some fungi have very beneficial effects for us. The drug Penicillin comes from a species of Penicillium, for example). Please note that the three effects outlined below are those for which we have some scientific evidence. There is anecdotal and epidemiological evidence for other types of health effects from things like MVOC

A) Allergic effects
Allergic effects, things like asthma, runny noses, and itchy eyes, effect a subset of the population. Probably 35% of the population is capable of developing an allergic response in general and 10% of the population to mold, in particular. It is important to recognize that the fungi do not have to be alive to cause an allergic response in sensitized individuals.

B) Toxic effects
A toxic effect is something that would affect everyone. It may be helpful to think of a toxic effect as coming from a poison. A poisonous mushroom will have a negative effect on essentially any person who would eat it. Toxic effects are much more controversial. Most of the information published in scientific journals deal with toxic effects due to ingestion. Most IAQ investigations assess fungal exposure due to inhalation. Various models, based upon conservative assumptions, do not support the claims that are made in the popular media. These models, in fact, support a conclusion that there is very little, if any, toxic effect in non-agricultural environments due to inhalation.

C) Opportunistic infections
An opportunistic infection means that the fungi are living off of the host. Ringworm and athletes foot are fungal infections. This is the only adverse health effect, from these three, that requires the fungi to be alive. For the majority of the population, fungal infections are not a serious concern. For those who are severely immune compromised, for example AIDS patients, people on immune suppressing drugs, and some of the elderly population, opportunistic infections can be a big deal. If somebody is doing an investigation that involves people who are severely immune compromised, in a hospital bone marrow transplant ward, for example, they should contact us, or another knowledgeable organization, to get advice because these types of fungal infections can be very serious, even fatal.

6. We get clients that call us and tell us they have "toxic mold" in their building. Is it possible to identify mold without a laboratory analysis?
If by "identify" you mean place into a genus, then the answer is "not really," unfortunately. I think that in some cases it is not necessary to have the fungi identified. If you have moldy bread, you know to throw it out without having to send it to a lab to be identified. Similarly, if it is known that the wall is covered in mold growth, the highly probably recommendation will involve remediation, regardless of the type of mold. For air samples, or when it is necessary to identify whether a black mark on a wall is a stain or fungal growth, it really is the best to have a laboratory take a look at it. Fungi come in a wide range of colors and types. They also may change their color based upon the conditions they are growing in. They may be bright yellow in one condition and dark green in another, for example. Consequently, if somebody says "I have a black mold on my wall. What is it?" You really do need an experienced mycologist to take a look at it.

7. Are there any persons or groups of persons more susceptible to mold allergens?
People must be genetically disposed to develop an allergy. So, that means that some people just will not ever have an allergic response to fungal exposure. We've had samples sent in from wine cellars with outrageously high airborne levels of fungal spores and none of the workers were complaining of adverse effects (and presumably it wasn't because they were drinking the wine). That profession conceivably self-selects for people who are not capable of developing an allergic response to fungi.

If people are capable of developing an allergic response, such as myself - I have an allergic response to certain fungi, they still must be exposed to the allergen in high enough concentrations and with enough exposures to develop the response. People are not just "born allergic" to fungi. They must both be genetically disposed and then exposed to fungi. Roughly 10% of the population is capable of developing an allergic response to fungi. That is why it is important to eliminate fungal growth within occupied buildings and prevent people from being exposed to higher levels of fungi than they would normally be exposed to. We do not want to cause them to develop an allergy that would have a negative impact upon their lives.

8. Do some molds produce highly toxic byproducts?
Yes. Some fungi produce very potent toxins. Aspergillus flavus, for example, produces aflatoxin, which is the most potent, naturally occurring toxin known to man. A. flavus grows on peanuts, and the level of aflatoxin that is permitted is federally regulated. Many mycologists actually won't eat peanuts because of this. We had a client who's peanuts had been rejected by the government because of the levels of aflatoxin exceeded the federal limit. He sent in soil samples from his farm and it turned out that the soil was just loaded with A. flavus. It was very unfortunate. Ironically, this means that the peanut butter you get in a health food store, may actually be worse for you than some plain old peanut butter from the regular store. Note that the exposure route described here is ingestion, not inhalation.