If These walls Could Talk

Chapter 3:
Overview of Mold, Mycotoxins
and Other Pathogens

As we discussed in the last chapter, when people think of mold, they associate mold as an allergen, which may trigger an allergic response. In some cases, many people may experience other health issues due to several molds ability of producing a toxin called a mycotoxin. Better known as toxic mold. However, the reality is molds have a very important function in our environment. Molds are the Earth’s cleansing mechanism. Molds break down dead matter, then biodegrade it. Without mold we would have leaves and garbage piled miles high.

The fact is, mold is everywhere. It is ubiquitous. Microscopically, mold is always floating around us. Therefore, unless you live in a bubble, there is no escaping the influence. However, because molds are an allergen and some potentially toxic, the last place you want an abundance of mold is in your home or environment.

Mold only needs three things for it to colonize. First, a proper food source which is anything that has cellulose. Cellulose is a long chain of linked sugar molecules that gives wood its remarkable strength. It is the main component of plant cell walls, and the basic building block from many textiles and for paper. Is it any wonder with most of our homes being built tight with stick framing and sheetrock, that so many homes and environments have a mold problem?

The next ingredients are the right temperature and water.

When it comes to temperature, molds can virtually grow in both cold and warm temperatures. Molds can colonize in temperatures ranging from thirty-two to one hundred twenty degrees Fahrenheit. Warm and moist conditions with temperatures falling into the range of seventy to ninety degrees Fahrenheit, are generally the most conducive for mold growth.

The biggest culprit of mold growth is water. Mold growth is a symptom of a much bigger problem—water and moisture intrusion. Water and moisture intrusion can come in a lot of forms. It can come in the obvious form of pooling water from a variety of sources such as a leak from a roof, pipe, or some water overflow. The other, more deceiving form of water intrusion which many times goes unnoticed is diffusion or water vapor.

Sub-grade environments such as basements and crawl spaces are notorious for this type of water intrusion. Water vapor comes through the foundation blocks or slab from hydrostatic pressure raising the relative humidity in the basement or crawl space areas. If the water vapor is not properly arrested through dehumidification, the excess moisture will be absorbed into wood framing, structural components, walls, ceilings, and contents. This then triggers the growth of not only mold, but other microbial organisms such as bacteria.

Typically, mold can grow within twenty-four to forty-eight hours, with several species of molds taking up to a couple of weeks. The illustration below lists three categories of mold growth.

• Primary colonizers (hours) Includes species: Wallemia, Penicillium, Aspergillus, and Eurotium
• Secondary colonizers (days) Includes species: Cladosporium, Phoma, Ulocladium, Alternaria, and also some species of Aspergillus such as A. Flavus and A. Versicolor.
• Tertiary colonizers (weeks) Includes species: Stachybotrys, Chaetomium, Ulocladium, Trichoderma, and Aureobasidium

It is estimated that there are well over several hundred thousand types of molds of which only around one hundred thousand have been studied. Molds come in a variety of looks, shades, and colors. The look of some molds are very apparent, while other molds can blend into the substrate they are feeding on and become almost transparent. One would need a very bright light illuminating the surface at the right angle to see if mold is colonizing.

Molds produce spores that are microscopically dispersed into the air, then gently wafting through the air in hopes of landing on surfaces that would provide the right food source, temperature and water to help it grow its colony. A great example of this is a dandelion that disperses its seeds into the air in hopes of landing on fertile ground to grow more dandelions.

Mycotoxins’ Purpose: Defense Mechanism

Mycotoxins are created by certain molds as a defense mechanism to protect their colony and food source. Not all mold types are capable of producing mycotoxins, nor do molds that can produce mycotoxins actually produce them. Molds that produce mycotoxins do so when they are competing with other molds, stressed, or feel their colony is being attacked.

As molds are breaking down the dead matter or bio-degrading it, a musty or mildew odor is often given off. This is part of the mold’s digestive process. The smell—called an MVOC or Microbial Volatile Organic Compound—is produced as a byproduct when mold is eating.

Molds are very competitive and territorial. As mentioned above, when different molds are growing in an environment and they start to compete, many molds—especially the molds from water damage—can produce a mycotoxin. Molds that are competing will produce these mycotoxins to ward off and kill other molds that may be infiltrating their colonies. Unfortunately, people living in this environment can get caught in the crossfire.

Bacteria is another pathogen in the home of which to be aware. Most people are familiar with mold. However, bacteria is the earliest colonizer and can literally grow in hours. Two types of bacteria commonly found in water damage environments are gram negative and gram positive bacteria. According to the Merck Manual–Consumer Version, gram negative bacteria are classified by the color they turn after a chemical process called gram staining is used on them. Gram negative bacteria stains red when this process is used. Other bacteria stain blue. These are gram positive bacteria. Gram negative and gram positive bacteria stain differently because their cell walls are different. Gram negative and gram positive bacteria can also cause different types of infections and as a result, it is important to test for both types of bacteria.

Gram negative bacteria are enclosed in a protective capsule. This capsule helps prevent white blood cells (which fight infection) from ingesting the bacteria. Under the capsule, gram negative bacteria have an outer membrane that protects them against certain antibiotics, such as penicillin. When disrupted or pierced, this membrane releases toxic substances called “endotoxins.” Endotoxins contribute to the severity of symptoms during infections from gram negative bacteria.

Gram negative bacteria can cause many serious infections such as pneumonia, peritonitis (inflammation of the membrane that lines the abdominal cavity), urinary tract infections, and more. The internalization of endotoxin in macrophages and endothelial cells results in local production of cytokines into the blood. These events can trigger a clinical response of toxic pneumonitis, airway inflammation, and other systemic symptoms. Inhalation challenges from breathing endotoxins in field studies confirm the relationship between these effects and exposure to dusts containing endotoxins.

Many gram positive bacteria can produce spores. One such bacteria is Actinomyces— a rod shaped and spore forming bacteria.

Actinomycetes is referred to as the connective link between bacteria and fungi because they form aerial filaments like fungi (filaments are smaller than fungi filaments). Actinomycetes like mold decompose organic material and enrich soil when is used as compost.

Gram positive and gram negative bacteria are a very large and diverse group of microorganisms. Understanding their taxonomy and knowing their unique features is important for diagnostic and treatment of infectious diseases.

According to the Surviving Mold website, many health effects are caused by exposure to the interior environment of water damaged homes or environments. The complex mixture of biotoxins present in the air and in the dust creates a soup of contaminates.

There are so many possible sources of these toxic compounds found in water damaged homes and environments that can then lead to a large variety of symptoms caused by mold Illness. No single compound can be identified as the sole cause of the inflammatory responses—or the illness—seen in affected people. Since no one thing can be deemed as solely responsible for the sickness, the sole cause becomes the water damage home or environment itself. This is the main reason when assessing a home or environment to expand the testing strategy for these multiple organisms.

A couple of years ago, I had the benefit of attending a Dr. Shoemaker medical conference in New Mexico. During that conference, Dr. Shoemaker discussed the importance of understanding not just mold in the environment, but bacteria as well. He went on to explain that the gram positive bacteria of actinomycetes can be a cause of major inflammation in the body. Since that medical conference, my company has been very focused on identifying both mold and bacteria in the environment. My experience in the field has shown an incredible correlation to the presence of gram positive bacteria (Actinomycetales), as well as gram negative bacteria, which can produce endotoxins in water damage environments. Furthermore, I have seen situations where in the home or the environment there were low levels of mold, no mycotoxins, and high levels of the...