Sick Buildings and Houses


We have previous covered the harm that fungi can cause as pathogens, i.e. fungi that can literally "grow" on you, and fungi that exude metabolites into our food, i.e. mycotoxins, thereby poisoning our food. However, another means by which molds can cause direct harm to us is our inhalation of their spores. In the examples we will be discussing, today, the fungi do not have to be inhaled followed by growth in our bodies as was the case in human mycopathogens. The molds that we will discuss today, cause harm through allergies or by the mycotoxins that are present on the spore surface. In recent years the latter has become a very important and controversial issue. Why is this the case? Much of it is hysteria, in my opinion, and appears to be media driven. Each time a mold infestation story, e.g. Hilton, Kalia Tower,  hits the front page, or the "overly-dramatized" news magazines such as 20/20 or Nightline, the number of email messages and phone calls concerning molds dramatically increases for a week or two. All of a sudden there is great concern about the molds that are seen growing in homes. Yet, in most instances, these molds have probably always been there and there was previously no concern about them. The media then has probably fueled this mass hysteria concerning the danger of molds. People have been advised to move out of their homes following identification of mold infestations. Some have invested their life savings to save their homes and to relieve them of the various afflictions that have come about as a result of the mold infestation, and sometimes to no avail, and finally trying to attain compensation from their insurance companies, previous owners or contractors who they believed were responsible for the mold infestation. However, litigation has proven to be a long and drawn out process since it is often difficult to scientifically demonstrate that an individual's illness has come about as a result of mold infestation.  Increase in litigation has also led to more insurance companies refusing to cover physical mold damages and any illness that may be claimed as a result of the molds. Nevertheless,  the number of lawsuits involving mold infestation in the home and workplace has continued to multiply. Some have compared health and physical damage caused by mold infestation to previous environmental crises such as asbestos and lead paint. 

Health related problems due to mold infestation will be divided into two categories: Those in the work place and those in the home. When occurring in the work place, it is often referred to as "Sick Building Syndrome". We will cover this category first.

Sick Building Syndrome

How many of you have had the following experience? You are employed in a large high rise or even just entered a high rise once, on business, that has central air conditioning, and one or more of the following symptoms occur:

After leaving the building the above symptoms would generally go away, but in some cases may persist for a short period of time. According to the April 1991 publication, of the Environmental Protection Agency (EPA) publication, on Indoor Air Quality, these symptoms are due to "sick building syndrome" (SBS). This term is used to describe situations in which building occupants feel ill, with the above symptoms, and these symptoms appear to be linked to time spent in a building. Specific causes for the symptoms, however, cannot be identified and that once leaving the building these symptoms generally go away. Also, the complaints from occupants of the building does not necessarily occur throughout the building, but may be localized in a particular room or area in the building. Sick building syndrome is distinguished from "building related illness" (BRI) where specific illnesses may be traced directly to airborne contaminants  in the building. Thus, what initially is labeled as SBS may later be changed to BRI, once the cause of specific symptoms have been determined. However, the latter is less common since it is often difficult to demonstrate that specific symptoms are due directly to a specific contaminant. Also, although SBS may be due to fungi, this is not usually the case.

Proliferation of Sick Building Syndrome During 1970's

According to the EPA (April, 1991), during the early 1970s, the demand for oil, in the United States, far exceeded our ability to produce it. The immediate impact was the OPEC oil embargo, in 1973, which led to an increase in our energy cost. Gasoline (regular) went from $0.30 a gallon, in 1970, to over $1.00 a gallon by 1980. In order to conserve energy, new commercial buildings erected and old buildings renovated were "sealed" in order to make them more energy efficient. Windows could no longer be opened from the inside, and air flow, cooling, heating and humidity were all controlled through a central ventilation system. Although the sealed buildings may be more energy efficient, according to a 1984 World Health Organization Committee report [in EPA (April 1991)], up to 30% of new buildings or buildings remodeled to be energy efficient may have problems with indoor air quality, which has led to SBS. There have probably always been problems with indoor air quality in commercial buildings. However, the act of sealing buildings has led to a decrease in indoor air quality by not allowing "contaminants" out of the system. Instead, if contaminants occur, they are now continually recirculated in the system. Contaminants in the air that have been linked to SBS may be divided into three categoris:

The above conditions may act in combination, and may be exasperated as a result of "sealing the building" for energy efficiency combined with the operation and maintenance of an air conditioning system in a matter not consistent with its operational guidelines. This may lead to inadequate air flow, high temperatures and humidity. that may encourage the growth of biological contaminants, which may circulate in the ventilation system. Even after a building investigation, it is possible that the specific causes of the complaints may not be discovered.

An example of a well known incidence of SBS took place in July 1976, during the celebration of the bicentennial of this country. A few days after an American Legion convention, at the Bellevue Stratford Hotel, in Philadelphia, 221 people became ill with a then unknown disease. Of these 29 died. This disease was called Legionnaire's Disease because 80% of the people who contracted this disease were Legionnaires. The Center for Disease Control would be called in immediately, but it would be 5 months before the actual cause of the disease would be isolated. The bacterium isolated was named Legionella pneumophila, and was later discovered to be in the hotel's cooling tower of the air conditioning system that provided an environment for the bacterium to breed to dangerous levels. The disease was then spread in the form of aerolized water droplets in the recirculated air in the hotel ventilation system.

Identification of Possible Sources of SBS

Since SBS can be the result of several pollutants circulating in the recirculated air of the ventilation system in commercial buildings and in order to determine the most likely cause of SBS several areas of expertise are often required:

Fungi as a Source of SBS

Early studies showed that the cause of SBS was mainly due to the high levels of chemical contaminants (Straus & Cooley, 1999). However, molds are known to cause allergies in both the indoor and outdoor environment, but until Straus & Cooley (1999), there were few studies that dealt with what molds were present in buildings with indoor air quality (IAQ) complaints and concerns. Their study examined 48 school buildings over a period of 22 months. Indoor and outdoor air samples were taken followed by remediation inside the schools where samples were taken. Indoor and outdoor samples were again taken following remediation. All samples were grown in a sterile, agar medium that would allow growth of the fungal samples.

The 48 schools had received complaints of IAQ from 622 (38% of total staff) occupants prior to remediation and never rose above 3% following remediation.  There were 5 molds that were consistently identified in the outdoor Cladosporium (81.5%), Penicillium (5.2%), Chrysosporium (4.9%), Alternaria (2.8%), and Aspergillus (1.1%). Generally, the authors observed that Cladosporium species were the dominant mold in outdoor air samples taken and in indoor air samples taken where complaints were not received by the occupants. However, in those indoor samples taken where complaints were received, Penicillium species were dominant. These results are summarized, below, in Fig. 1. However, in 11 schools, the percentage of molds identified from outside samples were similar to those found in areas where complaints were received. In these areas, visible growth of Stachybotrys chartarum was identified from samples isolated from swabs. The authors explained the absence of S. chartarum from air samples due to the difficulty of isolating this mold from air. This species requires a great deal of water on potential substrates before successful colonization can occur.

Figure 1. Summary of outdoor air samples, indoor air samples from complaint areas and indoor air samples from areas where no complaints were received. Graph based on Straus & Cooley (1999) publication.

The authors concluded from their results that Penicillium and Stachybotrys were associated with SBS in their study, and that Penicillium species were responsible for allergic reactions that are consistent with SBS symptoms. However, Stachybotrys chartarum produces the T-2 mycotoxins that is more toxic than allergenic to building occupants.

Molds in the Home

Although houses were not subject to the same environmental conditions as in commercial buildings, efforts to make houses more energy efficient, by insulation and sealing can also trap moisture in walls thereby providing an environment for fungal growth (Arnold Mann, USA Weekend, December 3-5, 1999). In addition, modern designs, poor construction and choice of building material has provided environments that encourage growth of molds (Broderick Perkins Realty Times, June 5, 2001). Since that time there have been many examples of mold problems in the home.

During the mid 1980's, in Minnesota, Michigan and Wisconsin, thousands of homes were reported to have mold problems, In November/December 1994, The Centers for Disease Control and Prevention, released a report documenting 10 of the 45 cases of pulmonary hemorrhage, in Cleveland, Ohio. They concluded in their study that there was an epidemiological association, in these infants, between pulmonary hemorrhage and water damaged homes that contained fungi with mycotoxins, which included Stachybotrys chartarum (there has since been a retraction on the conclusion of this study). Symptoms of pulmonary hemorrhage include coughing up blood and nosebleed. However, it has only been in recent years, that the public has become aware of mold problems in the homes. This was most likely due to the media exposure of mold infestation that had taken place in the Dripping Springs, Texas mansion belonging to Melinda Ballard and Ron Allison (Fig. 2).

Figure 2. Melinda Ballard, Ron Allison and son Reese outside of their home in Dripping Springs, Texas. Picture from USA Weekend, December 5, 1999


The story begins with a series of leaks that were repaired. However, Ballard and Allison were unaware of the water that had been trapped under their floor, which provided the environment for the growth and proliferation of S. chartarum. As the mold grew, the air conditioning system in their house circulated the mold throughout the entire house, but because most of the growth was inside the walls, it was months before the couple realized what was going on. During this period, their son Reese developed asthma, tremors, and learning problems. Allison began to lose his short-term memory and his ability to concentrate had become diminished. This eventually led to losing his job as an investment banker. It was only through a chance encounter with Bill Holder, an indoor quality air consultant that Ballard became aware that the family's problem was due to S. chartarum and other molds. Holder took samples at the couple's house and submitted them to David Straus, of the Health Sciences Center, at Texas Tech University. After analysis of the samples, Straus gave the house a level-4 S. chartarum diagnosis and advised the family to leave, immediately. Ballard sued Farmers Insurance Co. for $100 million for failing to act quickly on their floor damage when it was reported. In 2001 a jury awarded them $32 million, which has recently been reduced to $4 million. Since then mold-related insurance claims and lawsuits have multiplied, and builders and insurers have been preparing for the worst.

Not all litigations result in compensation for the afflicted owners. The case of Steve and Karen Porath is an example of a couple who literally lost everything. On April, 1999, the Poraths moved into their new home. It was a repossessed, 3-bedroom house, on 5½ acres that was purchased from the U.S. Department of Veteran Affairs. Their son Mitchell was borne 2 weeks later and within 2 days of coming home, he began vomiting. The vomiting became worst each day until he was vomiting up to about 50 times a day and was crying incessantly. The rest of the family also developed respiratory problems and nosebleeds. Steve Porath, 34, a construction worker was barely able to climb a flight of stairs because of the burning in his lungs. Karen Porath had problems with her throat and failing vision in one eye. She would eventually quit her job so that she could care her son Mitchell who was the hardest hit. Their other son, Blake, also had breathing problems, rashes and stomach pain. Although they are pursuing legal means to obtain compensation, it does not appear likely that anything will come of it. A representative from The U.S. Department of Veteran Affairs has taken the stand that they do not have any responsibility for the house and that it was purchased "as-is". When the Poraths finally determined the problems for their ill health, it was too late, financially. By that time they had already spent $200,000 on their home, over the 2 year period and they were told that it would cost them $75,000 to cleanse the mold from their house. Their other option they were given was to burn the house down to remove the mold infestation, which they did (Fig. 3)

Figure 3. Steve & Karen Porath watching their house burn. Sacramento Bee, February 15, 2001.

While there are many pending suits and also many on going cases, there is not yet any legal precedent which can be followed. To protect themselves, most insurance companies have excluded mold coverage from house insurance. Nationally, states are beginning to write guidelines as to responsibility of mold damage. California was the first to do so, with Governor Gray Davis signing The Toxic Mold Protection Act of 2001

This legislation requires The California Department of Health Services to establish a task force to determine the possibility of determining permissible exposure limits to mold exposure. The initial report was due July 1, 2003. Although this is not much, it is a beginning since there are presently no federal or other state agency standards that have established safe and unsafe limits to the amount of exposure to mold. Whether or not the California Department of Health Services can establish such limits is questionable. The problem is "how does one go about establishing such limits?" However, an important provision included in this act is that it requires that a seller or a person transferring real estate property give written disclosure to prospective buyers before transfer of title as to whether there is a mold problem. Landlords are also subject to the same disclosures before renting to tenants.

Is the Stachybotrys Problem Media Hype?

Although there is not a lack in the number of incidents of reported mold infestation in homes, there is not a great deal of scientific support correlating the symptoms observed and those known to be caused by S. chartarum mycotoxins. One case that has driven the anxiety/hype of mold problems involved a study carried out by the Center for Disease Control (CDC), in Cleveland, concerning pulmonary hemorrhage, in infants. The 1994 study concluded that there was a correlation between incidents of water damage and S. chartarum  growth in the home, and pulmonary hemorrhage in infants. However, recently, the CDC has retracted their conclusion and has admitted to flaws in their study. Despite the CDC retraction, there is still great anxiety concerning the earlier conclusion by the CDC.

As you recall from our introduction to mycotoxins, when we discussed the production of aflatoxin in Aspergillus flavus, the fact that a fungal species may produce a mycotoxin does not necessarily mean that it will always be produced. Generally, mycotoxins are produced only under specific environmental conditions. Thus, the presence of S. chartarum does not necessarily indicate mycotoxins are produced. The group of mycotoxins produced by S. chartarum is called trichothecenes, the same group that occurs in Fusarium and at least 3 other genera of molds. Stachybotrys produces 3 unique trichothecenes, and the T-2 toxin that was previously discussed as being produced by Fusarium species. The T-2 toxin is present on the surface of S. chartarum spores. Thus, it is possible that inhalation of spores is of concern. However, most of the literature that is known about T-2 toxins is its effects when ingested. One which we discussed was between 1942-47, in several districts of Russia, more than 10 percent of the population was affected and many fatalities occurred from consumption of Fusarium contaminated grains. Symptoms of ingestion include vomiting, immunosuppression, bleeding from nose and throat, and multiple and subcutaneous hemorrhages. However, in many recent cases in litigation, including that of Melinda Ballard and Ron Allison, symptoms included headaches, fatigue, irritability and difficulty concentrating or brain damage, toxic encephalopathy, cognitive deficits, neurobehavioral deficits, and neuropsychological impairment, but the T-2 toxins has never been demonstrated to be neurotoxins. Nevertheless, these were some of the symptoms described in in which S. chartarum has been involved. On the other hand, it is difficult to argue against physical evidence. Visible growth of S. chartarum could be observed in abundance throughout their house, the entire family suffered from various ailment, including neurological ones. Finally, after only 30 minutes of examining the house, with a respirator on, David Straus of Texas Tech, was puking his guts out, hours after leaving the house and now has apparently suffered permanent hearing loss in one ear. Difficult to decide? You bet!

A few studies involving physical contact with S. chartarum have been published. In 1977, 23 workers had developed sore throat, bloody nasal discharge, burning and watering eyes, swollen, crusted skin on the face and dermatitis within 24 hours after loading moldy hay. These symptoms vanished within a week after discontinued contact to the moldy hay. In Russia there have been veterinary reports of mycotoxin poisoning, in horses and humans, caused by S. chartarum infected straw or hay. Symptoms included severe dermatitis, chest pain, sore throat, bloody rhinitis, cough and leukopenia. However, with the two physical cases summarized, above, spore densities were estimated in the millions per m3 and spore density is significantly lower in typical or even in mold infested homes.  For example,  in St. Louis, during the summer months, spore levels, as measured by the NAB of the American Association of Asthma, Allergy, and Immunology (AAAAI) range from 30,000 to sometimes as high as 75,000 spores/m³. Yet, families have been asked to leave their homes with spore counts as low as 1,000 - 5,000 spores per m3. So, has there been an over-reaction to asking families to leave their home? Could all of their worldly possessions been saved by simply removing it from the moldy environment?

Although the Toxic Mold Protection Act of 2001, in California, is an effort to promote critical scientific evidence in mold litigation, the reality of producing guidelines in the near future is unlikely. One of the duties of the task force was to determine if it is possible to definitively assess if an individual has been exposed to toxic mold, and the extent of that exposure. At this time, this is not possible because there are no validated biomarkers, that is a means by which we can quantitatively measure exposure to molds utilizing blood or urine samples, for inhalation of S. chartarum or other molds. There are biomarkers for aflatoxins ingestion, but not for inhalation of toxins (spores). Some physicians have utilized serum antibodies to S. chartarum antigens to indicate exposure to molds or their mycotoxins. When an individual is exposed to a mold, proteins called immunoglobulins (Ig) are produced by B-lymphocytes (white blood cells) that can make antibodies against the mold.  The type of antibody produced is based on the antigen of the mold detected. In the case of S. chartarum, a commercial antigen is available that has been utilized to determine if exposure to this mold has occurred. Blood is drawn from the possibly exposed individual and tested against the antigen. However, a positive reaction to the antigen has proven unreliable in determining exposure to S. chartarum. The antigen has recently been demonstrated to "cross-react" with antigens of Aspergillus fumigatus and Alternaria alternata. Thus, a positive reading indicating exposure to S. chartarum, may also indicate that exposure to A. fumigatus or A. alternata.

Most of this lecture was based on the following articles:

Anon. Indoor Air Facts No. 4 (revised): Sick Building Syndrome (SBS). Indoor Air Publication, Environmental Protection Agency. April 1991.

Campos, Art. Sick of mold, they torch home: Illnesses and lack of money lead family to raze ailing dream house in Foresthill. Sacramento Bee. February 15, 2001.

Mann, Arnold. Mold: A Health Alert. USA Weekend. December 5, 1999.

Perkins, Broderick. $32 Million Verdict in Mold Case. Realty Time. June 5, 2001

Straus, D.C. & J. D. Cooley. 1999. The Role of Fungi in Sick Building Syndrome. Lubbock Magazine. October: 56-59

 Mycological Terms

  1. Building related illness: Situation in which building occupants feel ill and specific illnesses may be traced directly to airborne contaminants in the building.
  2. Sick building syndrome (SBS): Situations in which building occupants feel ill, and the illness appears to be linked to time spent in a building. Specific causes for the symptoms cannot be identified and that once leaving the building these symptoms generally go away. Causes examined are chemical contaminants from indoor and outdoor air, and biological contaminants.
  3. Stachybotrys chartarum: Species of mold often implicated in SBS and illnesses in homes. However, symptoms of illnesses are not consistent with those that are known in T-2 trichothecene.
  4. Toxic Mold Protection Act of 2001: Legislation, passed in California, requiring the California Department of Health Services to establish a task force to determine the possibility of determining permissible exposure limits to mold exposure. The initial report was due July 1, 2003. This may be an impossible task to carry out at this time. However, it is at least a beginning since there are presently no federal or other state agency standards that limits the amount of mold contaminants.
  5. Biomarkers: A means by which we can quantitatively measure exposure to molds utilizing blood or urine samples. Although such a test is available for ingestion of various mycotoxins, one is not available for inhalation of mycotoxins.
  6. Immunoglobulins (Ig): proteins produced by B-lymphocytes (white blood cells) that can make antibodies against molds. The type of antibody produced is based on the antigen of the mold detected. Commercial antigens available for S. chartarum in order to determine if exposure to this fungus has occurred. Blood is drawn from the possibly exposed individual and tested against the antigen. However, a positive reaction to the antigen has proven unreliable in determining exposure to S. chartarum since it has been demonstrated that the antigen also gives positive reactions for other species of molds. Thus, a positive reaction may not indicate exposure to S. chartarum.

Questions to Think About

  1. From reading this page, do you think that recent illnesses in homes and in the work place are true indicators that there are mold problems, specifically with Stachybotrys chartarum?
  2. What are the three sources of contaminants examined when there are complaints of Sick Building Syndrome (SBS)? Who are you going to call if you suspect that SBS is a problem?
  3. The beginnings of SBS seems to have started around the 1970s. What event that occurred in the early 1970s can you link to the onset of SBS?
  4. Although biological contaminants, such as fungi, may be the cause SBS, this is not usual the case. What is most often the cause of SBS?
  5. You have now read both sides of the story (I hope) of the case of Melinda Ballard and Ron Allison. Do you think that their health problems are caused by Stachybotrys chartarum? Regardless of your answer, be able to defend your answer.
  6. Give some conflicting evidence that indicate that the barrage of mold illnesses that have been occurring is at least not caused by Stachybotrys chartarum.

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