Moldy Home?

In the last few years, many people have e-mailed asking about the relationship between fungal infection of homes or workplaces and developing allergies and other more serious health problems. Many have read or heard about "sick building syndrome" reportedly caused by some subspecies of Stachybotrys chartarum.

Although it has infused the field of mycology with much needed attention and cash, there is still considerable debate within the mycological community about the role that Stachybotrys plays in the health of people that exhibit, a diverse suite of symptoms placed under the umbrella, "sick-building syndrome." Certainly the truth has been muddied by much of the mass media attention, that several years ago, bordered on hysteria.

Unfortunately, as with many syndromes, it is difficult to prove a cause and effect relationship. To my knowledge (and this may be suspect), the connection between serious health problems and presence of genera like Stachybotrys has not been definitively proven. There is no doubt, however, that some strains (not all) of Stachybotrys chartarum can produce toxins and do cause illnesses, especially when consumed in large quantities. This only confuses matters. So where is the truth? Being a skeptic, I would rather see additional evidence to suggest that microfungi, like Stachybotrys, can cause serious health problems when found in buildings. The mere presence of the fungus and illness in the same house does not prove a cause and effect relationship.

When considering your situation or predicament . . . please keep in mind:

• 1.  Stachybotrys produces spores (conidia) in slimy droplets not designed to be dispersed by air currents. So, unless the mold is dried and disturbed, I would not expect Stachybotrys to get into air currents where it can be inhaled.
• 2.  Many species/genera of microfungi are specialized to disperse using air currents and many people are sensitive to these spores, but few respond by exhibiting serious health problems. Most develop "mild" allergic responses like, itchy, watery eyes, sneezing, etc. That is not to say mold in homes is not a serious problem. I would argue, that in most cases, the mold is more detrimental to your home's physical structure than to your health. Nevertheless, there are a few of you that may be particularly sensitive to molds. In those cases, it would behoove you to allow a complete assessment of your home by a specialist familiar with fungal species and structural composition of your home.
• 3.  Few fungi can grow without a source of water. Most, if not all, problems with fungal growth in homes is directly related to the availability of water at or near the problem areas. Stop or reduce the water availability and the problem is likely to go away.
• 4.  How you sample your home will determine how many and what type of fungi you are likely to find. For example, some home inspection consultants will sample your basement by rubbing a piece of sticky cellophane onto problem areas on the drywall. The resulting estimate of the amount of fungal infection is, predictably, disproportionately high. If the contaminated area only encompasses a few square centimeters, the estimate of fungal numbers is, for the most part, meaningless. The degree of fungal infection of any area or volume is a function of many variables, too numerous to list here. Suffice to say that there is no ONE method of accurately assessing the prevalence of fungi in indoor environments.

More recently, the CDC has published a common-sense piece that describes fungal ecology of water-damaged homes in the aftermath of hurricanes Katrina and Rita in the New Orleans area.  Although some of the recommendations are specific for this catastrophe, I think you will find much helpful information and recommendations concerning mold growth in general.  If you are interested in this document please click here. 

I hope I helped with some of your concerns. I don't think I've offered any easy answers, but every case is particular and needs individual assessment. If you still have questions or concerns, please do not hesitate to contact me.

Thanks.