Mycotoxins in indoor environments. Determination using mass spectrometry

Abstract: Dampness in indoor environments may cause various health problems. The specific causative agent(s) are unknown but may originate from degradation processes in damp materials, microbial growth, or a combination of these phenomena. The health impact of dampness in buildings is a politically, legally, and economically important question. Scientists at the U.S. EPA and Lawrence Berkeley National Laboratory have estimated that the symptoms of 4.6 of the total of 21.8 million asthmatics in the USA are caused by indoor dampness and mold to an annual cost of 3.5 billion dollars. Mycotoxins are secondary metabolites produced by molds which may be e. g. cytotoxic (e. g. macrocyclic trichothecenes produced by Stachybotrys chartarum), genotoxic (e. g. sterigmatocystin and aflatoxins produced mainly by Aspergillus spp. including A. versicolor and A. flavus), or immunosuppressive and neurotoxic (e. g. gliotoxin produced by Penicillium spp. and Aspergillus spp. e. g. A. fumigatus). Airborne mycotoxins have been demonstrated in water-damaged buildings using both ELISA and mass spectrometry. However, whether mycotoxins at the concentrations found in mold-damaged environments represent a health risk upon inhalation is not known. The mechanisms for mycotoxin uptake, metabolism, and interaction e. g. with other fungal constituents such as proteins and (1?3)-?-D-glucan (a fungal cell membrane constituent) are poorly understood. In this project analytical methods for the detection and determination of selected mycotoxins using GC-MS and HPLC-MS were developed. The methods were applied to 167 mold-contaminated building material samples, of which 67 % were mycotoxin positive. Thus, many molds not only posess the genetic capacity to produce mycotoxins but do it regularly in water damaged indoor environments. In addition, we demonstrated mycotoxins in dust settled in the breathing zone in indoor environments where severe mold-contamination was identified on building materials. We thereby confirm that mycotoxins on such materials can become airborne and thus inhalable. This project is an example of fruitful national and international inter-disciplinary collaboration between the building industry, companies specialized in remediation measures, and universities.