What Is "Sick Building Syndrome"?

In the early 1970’s “sick building syndrome” (SBS) was coined to describe “unexplained” illness among occupants of certain new office buildings. Occupants complained of inflamed mucous membranes, respiratory problems, fatigue, headaches, and neurocognitive changes. Basically, when they went to work in these newly constructed office buildings their noses began to run, their throats got sore, they felt tired, headachy, had difficulty breathing, and sometimes even lost concentration and attentiveness. However, whenever they left the building their symptoms started improving. Something in the building was making these people feel “sick.” This illness came to be called “building related illness (BRI).

The “Indoor Environmental Quality (IEQ)” as the name implies refers to the quality of the air inside a building. In the early days Indoor Environmental Professionals mostly concentrated their efforts on chemical emissions or Volatile Organic Compound (VOC) emissions from paints, adhesives, carpeting and other flooring materials, and other assorted building materials. However, even when these items were addressed or their “offgassing” of VOC emissions had subsided, the BRI remained. It was obvious that something else was factoring in to cause Sick Building Syndrome.


The American Industrial Hygiene Association (AIHA) has concluded this about the relationship between BRI/SBS and moisture and mold contamination:

Although biological contaminants have been given little attention until relatively recently, substantial proportion of building-related illness (BRI) and sick building syndrome (SBS)…is the result of exposure to such contaminants… There is abundant evidence from investigations in several countries that symptoms of eye, nose, and throat irritation as well as cough and tiredness and fatigue are present in excess among persons or populations in certain buildings. Although several agents have been suggested as causative, the most extensive evidence is found for dampness and mold.
– AIHA 1996 “Field Guide for the Determination of Biological Contaminants in Environmental Samples”

Basement flooding resulting in
extensive mold growth

So what does this all mean? If you have moisture in your building/home you have reason for serious concern. Basically, moisture is vital to the growth of mold.

“Moisture must be continually present for a mold colony to grow. Dampness, which is noted only by minor moisture/condensate, is adequate for some mold, including species of Aspergillus and Penicillium, molds that are thought to be a problem to the health of some building occupants.” – University of Connecticut Health Center (September 30, 2004)

If you have/had a roof leak, pipe leaking, flooding, HVAC troubles or otherwise high indoor humidity (above 50%) you have conditions, which can promote mold growth. These sources of moisture must be found and fixed. The materials they have affected must be moisture measured, inspected, and if moldy, remediated.


Musty, “mildewy”, moldy, funky … there are many words to describe it, but it all means the same thing, you have mold. These are technically called MVOC-s (microbial volatile organic compounds). It’s the odor given off by active mold growth. We say growth because you are actually smel-ling the “gas” given off by microbial digestion. Yes, we all do it and mold is no different. Some will try to say that these secondary metabolites are toxic to humans. However, this has not been proven.

The notion that indoor mold growth can lead to significant toxicity in occupants of “moldy buildings” has been very controversial in the scientific literature and likely will remain so for the foreseeable future. – University of Connecticut Health Center (September 30, 2004)

What we do know is that too much of anything is not good. If you smell mold it means it is there and it is growing, and it should be taken care of.


Some mold is obvious and easy to clean. For example, mold growing on the surface of your shower area. This can be easily and safely cleaned as part of your normal housekeeping. However:

”In some cases, indoor mold growth may not be obvious. It is possible that mold may be growing on hidden surfaces, such as the back of dry wall, wallpaper, or paneling, the top of ceiling tiles, the underside of carpets and pads, etc. Possible locations of hidden mold can include pipe chases and utility tunnels (with leaking or condensing pipes), walls behind furniture (where condensation forms), condensate pans inside air handling units, porous thermal or acoustic liners inside ductwork, or roof materials above ceiling tiles (due to roof leaks or insufficient insulation). Some building materials such as dry wall with vinyl wallpaper over it or wood paneling, may act as vapor barriers, trapping moisture underneath their surfaces and thereby providing a moist environment where mold can grow. You may suspect hidden mold if a building smells moldy, but you cannot see the source, or if you know there has been water damage and building occupants are reporting health problems. Investigating hidden mold problems may be difficult and will require caution when the investigation involves disturbing potential sites of mold growth – make sure to use PPE. For example, removal of wallpaper can lead to massive release of spores from mold growing on the underside of the paper. If you believe that you may have a hidden mold problem, you may want to consider hiring an experienced professional.” – Mold Remediation in Schools and Commercial Buildings, EPA (Environmental Protection Agency) 3/2001

Mold hidden
behind wallpaper

So what defines an “experienced professional.”? Fortunately, the Institute of Inspection Cleaning and Inspection (IICRC), in the only “mold standard” yet published, has defined this person as an Indoor Environmental Professional (or IEP):

An individual that is qualified by knowledge, skill, education, training and /or experience to perform an assessment of the fungal ecology of property, systems and contents at a job site, create a sampling strategy, sample the indoor environ-ment, interpret laboratory data and determine Condition 1, 2 and 3 status for the purpose of establishing a scope of work and verifying the return of the fungal ecology to a Condition 1 status. – IICRC S520 Standard and Reference Guide for Professional Mold Remediation

The IICRC further advises how this Indoor Environmental Profes-sional is to be used:

When a preliminary determination indicates that mold contamination (as defined in S520) exists or is likely to exist, it is highly recommended that an assessment (as defined in S520) be performed prior to starting remediation. It is highly recommended that an independent IEP with no business affiliation to the remediator be used for this purpose.

It is important that you have an unbiased and knowledgeable person(s) assessing the condition of your home/building. Mold must be handled carefully and under a very specific protocol of procedures and engineering controls to protect the health of occupants and prevent the spread of contamination to previously unaffected areas.


At Oasis Indoor Environmental we are dedicated to serving you as the occupant of the home/building. We are mold and moisture specialists. We are Indoor Environmental Professionals. We understand mold, how it grows, how it gets into the air, and how to clean it up.

We will use occupant interviews, visual/olfactory inspection, moisture readings (ambient and building materials), and site-specific sampling strategies to assess if and to what extent mold, allergens, or other environmental stressors are compromising your environment. We perform a comprehensive assessment, assume nothing, and personally care about you and your health. In the end you will receive a report explaining not only results of our assessment and interpretation of any applicable lab evidence, but also a written protocol outlining how to mitigate or remediate the problem. We will work with your mold remediation contractor to monitor the job and provide the 3rd party clearance that it was done right and to completion. Most of all, we are there for you. If you have any questions or concerns we are happy to talk with you. If you need us to explain your building’s condition to other concerned parties we are qualified and happy to do so.

I hope that this article has helped answer some of your questions and provided you some direction in how to handle your indoor environmental quality issues. Please call us with any questions you may have. We look forward to serving you and serving to improve the health of your building.

– Spencer Hampy CIE, CMC
– President Oasis Indoor Environmental Inc.

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