Detection of airborne trichothecene mycotoxins from Stachybotrys chartarum and their relationship to sick building syndrome

Abstract

The growth and propagation of fungi in water-damaged builduigs has long been recognized as a potential health risk to occupants of such environments. Reported symptoms from inhabitants of these "sick" buildings range from allergic rhinitis, headaches and watering of the eyes to more severe symptoms that warrant considerable concern such as hemorrhaging, nausea/vomiting/diarrhea, dizziness, and loss of mental capacity. Of the fungi capable of contaminating indoor environments, Stachybotrys chartarum is thought to pose the most significant human health risk. S. chartarum is a known producer of many compounds that have the potential to adversely effect occupant health, the most noteworthy being the highly toxic macrocyclic trichothecene mycotoxins. Currently, the relationship between the presence of trichothecene-producing strains of S. chartarum in water-damaged buildings and adverse human health effects is unclear. This is primarily due to the lack of data showing the co-presence of this organism and its mycotoxins (in an airborne state) in such environments.

In this study, we present evidence that S. chartarum trichothecene mycotoxins become airborne and exist in buildings contaminated with this organism Under controlled situations, we were repeatedly able to separate and collect airborne particulates originating from Stachybotrys growth. Our results demonstrated that airborne trichothecene mycotoxins were present on large, poorly respirable particles such as intact conidia, as well as highly respirable particulate matter such as fungal fragments. Furthermore, we were able to collect airborne trichothecene mycotoxins in natural indoor environments contaminated with S. chartarum, one in which separation and collection of particles was done as in our controlled setups. Concentrations ranged from less than 10 to greater than 1000 pg/m3 of sampled air.

In addition, we present data demonstrating that these compounds can be detected in sera from individuals with known mold (specifically S. chartarum) exposure. Overall concentrations were low with the exception of two samples that demonstrated uniquely high values (43 and 84 ng/ml) indicating a definitive exposure. When looked at in total, our data show that airbome trichothecene mycotoxins can be isolated in Stachybotrys chartarum-contaminated buildings and, based on their detection in human serum samples, may represent a significant occupant health risk.