Mold Causes and Effects “in a Material World”

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Abstract

Microorganisms, including mold and yeast, are everywhere. You may be breathing some noxious spores right now as you are reading this article. Journalists interested in sensationalism call most of the mold that causes health issues or property damage “black” mold or “toxic” mold. Stachybotrys chartarum (also known as Stachybotrys atra) and other fungi/molds have made it into the public's consciousness. In this article, you will see that there is no such thing as “toxic” mold. Bacteria and fungi can and do produce secondary metabolites called toxins. These bacteria and fungi are called toxigenic, or capable of producing toxins. The fact is that not all molds are pigmented, and certainly, not all of them are “black.” The things you cannot see, the respirable conidia/spores, volatile organic compounds (VOCs), and toxins, are potentially more dangerous than many of the organisms you can see. Here, we explore what we currently know about the effects of water intrusions, water-damaged materials, and the growth of potentially pathogenic and toxigenic mold.

Introduction

In 2007, we wrote an article on the controversies surrounding “sick building syndrome” [1] and building-related illnesses. Nine years later, we took a second look at potentially pathogenic and toxigenic molds, i.e., the molds that are associated with these illnesses. We found that of the potentially pathogenic, toxigenic fungi, Stachybotrys (Fig. 1), once the sole media darling, has been joined by Chaetomium (Fig. 2), Fusarium (Fig. 3), Aspergillus (Fig. 4), Alternaria, and others; these fungi are known to have effects on human health. While Stachybotrys may still be in the mix and can cause serious problems, there are other molds that can and do have the ability to cause disease.

Section snippets

Toxigenic Mold in the Bible and in the News

The first story about mold was written in the Old Testament (Leviticus 14:33-45). In it, the Lord tells Moses and his brother, Aaron, how to “remediate” a house with mold. A priest should inspect the affected home, scrape mold from all the walls, and discard all contaminated material in an unclean part of town. If that did not work, the house should be completely demolished [2].

Modern day media attention to mold began in late 1996-1999 regarding Melinda Ballard's house in Dripping Springs,

Toxigenic Mold

In 1969, fungi were removed from the plant kingdom and given their own kingdom, Fungi. It was discovered on the molecular level that most fungi have a polysaccharide cell wall made of chitin, which is similar to the outer shell of a cockroach and not at all related to plants [7]. Fungi are designed to decompose various substrates. Many of them decompose cellulose, while some, such as Chaetomium and Stachybotrys, are lignin decomposers that decompose wood and wood products. The term “toxic mold”

Mycotoxins

Mycotoxins are low-molecular-weight, naturally occurring secondary metabolites (products) of molds [7]. Of note, mycotoxins are so dangerous that the T-2 mycotoxin of Stachybotrys and Fusarium has been used for biological warfare [8].

Stachybotrys has been isolated only once from a human infection at Texas Children's Hospital in Houston, Texas [10, 11]. The patient was a child who had symptoms associated with pulmonary hemosiderosis. Pulmonary hemosiderosis is a rare disease characterized by

What the Experts Currently Say About Health Effects

In 2004, the Institute of Medicine reported that damp, moldy conditions may cause respiratory symptoms, like wheezing and coughing, that could lead to asthma or reactive airway disease in healthy people [18]. They also found limited or suggestive evidence linking indoor mold exposure and respiratory illness in otherwise healthy children. By 2009 and 2011, respectively, the WHO and the CDC had published the following papers: WHO Guidelines for Indoor Air Quality: Dampness and Mould [19] and a

Issues Regarding Mold Remediation

Usually, the process for mold remediation first begins by someone noticing or smelling mold indoors. There are a number of reasons for indoor moisture and musty odors. They include façade, window, and roof leaks; improper installation of vapor barriers; plumbing leaks; HVAC problems; flooding or condensation of moisture; and sustained high relative humidity. In addition, individuals in the building may have noticed the smell of VOCs, off gassed (released) by both bacteria and molds, which are

Conclusion

In summary, while the cause of toxigenic mold growth may be well supported, much more documented support for its health effects is still needed, and therefore, this is a work in progress. We are not where we need to be in fully recognizing the seriousness of what toxigenic mold can do and, most importantly, preventing and minimizing its health effects. The next decade will hopefully prove beyond a doubt, within the medical community and the judicial system, that there can be disastrous health

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