Interview with a Toxicologist

Dr. Jack Thrasher took an interest in our family in October of 2008. An air sample with 260,000 spores of stachybotrys is extreme. He described the bacterial contamination that goes along with this kind of exposure and explained the health hazards involved.

Dr. Thrasher ought to be retired. "Too many people are suffering. I can't retire," he says. I'm glad he hasn't. You can find out more at his website.

Before the interview began Dr. Thrasher wanted to make something clear. This is powerful. Slamming a door can dislodge mold spores! In his words:

Let us keep in mind that air sampling does not detect hidden mold growth. Mold growth is hidden in places we do not see: attic, wall cavities, crawlspace, back side of carpeting and wall board. The attic wall cavities and crawl spaces are in communication with the interior of the home/building. Pressure shocks dislodge mold spores from these areas into the interior of the home. The pressure shocks include wind and opening and closing of doors.


1. What is a toxicologist?

Good question. Most lay people do not understand what a toxicologist is. Basically, he/she studies the adverse (sometimes it can be beneficial) effects of organic and inorganic chemicals (heavy metals) on animals and humans. The studies undertaken involve pathology and the biochemical effects of the toxins. For example, it is established that mycotoxins produced by several species of molds can have several toxic effects. These include inhibition of protein synthesis, adduction to proteins and DNA producing adverse effects on the function of these biological molecules, inducement of cell death (apoptosis), toxicity to the immune system and brain, and synergism (the ability of one chemical to increase the toxicity of two chemicals combined). In this latter category it has been demonstrated that mycotoxins have synergism, mycotoxins and endotoxins (lipopolysaccharides) have synergism, and toxins produced by certain bacteria (Streptomyces and Nocardia) have synergism with mycotoxins.

2. Not all toxicologists understand mold the way you do. How did you come to have this area of expertise?

I do not know about other toxicologists, but I pride myself on reading and understanding all of the peer reviewed literature I can locate regarding a given toxic compound. In the case of indoor air there is a multitude of potential toxins. The indoor biocontaminants that occur in relation to water intrusion and microbial growth are an excellent example of this. The media, attorneys, and the medical profession have zeroed in on only two aspects of this environment: Molds and their mycotoxins. In reality the indoor environment is a complex mixture of biological contaminants. These include molds and their by-products, such as mycotoxins and hemolysins; bacteria and their by-products (gram negative and positive bacteria); microbial volatile organic compounds; exotoxins and endotoxins produced by bacteria; particulates, ranging from nanoparticles up to mold spore size, glucans and galactomannans. Dr. Brasel and Dr. Gorny have demonstrated that the particles less than 2 microns also contain a significant quantity of bacterial and mold toxins. These small particles are inhaled deeply into alveolar spaces of the lungs and readily release their toxins into the blood. Thus, Dr. Brasel demonstrated trichothecenes in the sera of exposed subjects, while Van Emon demonstrated Stachylysin (hemolytic protein) in a different group of exposed humans. Also, nanoparticles (part of this fraction of particulates) readily enter the bloodstream from the alveolar spaces. Finally, Dr. Calderon-Garciduenas has demonstrated that particles attached to the olfactory neurons in the nasal cavity travel up the olfactory tract and enter the brain of humans, causing brain damage.

I have reviewed the literature on these various aspects and I have written a paper titled: "The Biocontaminants and Complexity of Damp Indoor Spaces: More than Meets the Eyes." This paper is scheduled to be published in Toxicology and Industrial Health in the September/October issue along with approximately 16 other papers on the adverse effects of exposure of humans to damp indoor spaces.

More next time.