Dampness in buildings has been linked to adverse health effects, but the specific causative agents are unknown. Mycotoxins are secondary metabolites produced by molds and toxic to higher vertebrates. In this study, mass spectrometry was used to demonstrate the presence of mycotoxins predominantly produced by Aspergillus spp. and Stachybotrys spp. in buildings with either ongoing dampness or a history of water damage. Verrucarol and trichodermol, hydrolysis products of macrocyclic trichothecenes (including satratoxins), and trichodermin, predominately produced by Stachybotrys chartarum, were analyzed by gas chromatographytandem mass spectrometry, whereas sterigmatocystin (mainly produced by Aspergillus versicolor), satratoxin G, and satratoxin H were analyzed by high-performance liquid chromatography-tandem mass spectrometry. These mycotoxin analytes were demonstrated in 45 of 62 building material samples studied, in three of eight settled dust samples, and in five of eight cultures of airborne dust samples. This is the first report on the use of tandem mass spectrometry for demonstrating mycotoxins in dust settled on surfaces above floor level in damp buildings. The direct detection of the highly toxic sterigmatocystin and macrocyclic trichothecene mycotoxins in indoor environments is important due to their potential health impacts.Microorganisms are thought to be involved in health problems connected to damp buildings. However, the causative microbiological agents are unknown (22). Many molds that thrive in damp indoor environments are potent mycotoxin producers and may play a role in the reported adverse health effects ( 1,5,17,23,24,26,30). Mycotoxins are secondary metabolites, e.g., produced to give molds strategic advantages over encroaching organisms. Examples are sterigmatocystin (STRG), a carcinogenic mycotoxin produced mainly by Aspergillus versicolor; satratoxin G (SATG) and satratoxin H (SATH), which are cytotoxic mycotoxins produced by Stachybotrys chartarum; and citrinin, gliotoxin, and patulin, produced by, e.g., Aspergillus spp. and Penicillium spp. The latter three mycotoxins have been shown to be immunomodulatory, causing a polarization in cytokine production towards a Th2 phenotype (36), and citrinin caused depletion of intracellular glutathione at nontoxic concentrations (18). Based on spore counts, the airborne mycotoxin concentrations found in damp buildings have been estimated to be insufficient for causing adverse health effects (20). However, indoor molds may fragment into very small airborne mycotoxin-containing particles, resulting in up to a 500-fold larger exposure than assumed previously (4,11,21,32). In addition, Cho et al. (7) showed that the respiratory deposition of S. chartarum fragments was over 200-fold higher than that of spores in adults and an additional 4 to 5 times higher in infants. These aerosolized fragments could potentially also be the source of allergens (13).S. chartarum and A. versicolor are two commonly encountered molds in buildings with moisture problems (9,12,...

Mycotoxins are toxic, secondary metabolites frequently produced by molds in water-damaged indoor environments. We studied the prevalence of selected, potent mycotoxins and levels of fungal biomass in samples collected from water-damaged indoor environments in Sweden during a 1-year period. One hundred samples of building materials, 18 samples of settled dust, and 37 samples of cultured dust were analyzed for: (a) mycoflora by microscopy and culture; (b) fungal chemical marker ergosterol and hydrolysis products of macrocyclic trichothecenes and trichodermin (verrucarol and trichodermol) by gas chromatography-tandem mass spectrometry; and (c) sterigmatocystin, gliotoxin, aflatoxin B(1), and satratoxin G and H by high performance liquid chromatography-tandem mass spectrometry. Sixty-six percent of the analyzed building materials samples, 11% of the settled dust samples, and 51% of the cultured dust samples were positive for at least one of the studied mycotoxins. In addition, except in the case of gliotoxin, mycotoxin-positive building material samples contained 2-6 times more ergosterol than mycotoxin-negative samples. We show that (a) molds growing on a range of different materials indoors in water-damaged buildings generally produce mycotoxins, and (b) mycotoxin-containing particles in mold-contaminated environments may settle on surfaces above floor level. The mass spectrometry methods used in this study are valuable tools in further research to survey mycotoxin exposure and investigate potential links with health effects.

We compared the efficiency of some commercially available products and methods used for remediation of mould-contaminated building materials. Samples of gypsum board and pinewood were artificially contaminated with toxin-producing isolates of Stachybotrys chartarum and Aspergillus versicolor, respectively, then, ten different remediation treatments were applied according to the manufacturers' instructions. Microbial and chemical analyses of the infested materials were carried out both immediately before and after treatment, after six weeks of drying at room temperature, and after another six weeks of remoistening. The aim of the study was to determine whether the investigated methods could inhibit the mould growth and destroy some selected mycotoxins produced by the moulds. None of the decontamination methods tested could completely eliminate viable moulds. Some methods, especially boron based chemicals, ammonium based chemicals, and oxidation reduced the contents of mycotoxins produced by S. chartarum (satratoxin G and H, verrucarol), whereas the one which uses an ammonium based chemical reduced the amount of sterigmatocystin produced by A. versicolor with statistical significance. No remediation treatment eliminated all the toxins from the damaged materials. These results emphasize the importance to work preventively with moisture safety throughout the construction processes and management to prevent mould growth on building materials.

Gypsum boards infested by Stachybotrys chartarum are often found in built-in constructions. A PCR-based analysis method has been developed for S. chartarum using specific primers based on the Tri5 gene. Another method for detecting fungi is by species identification via sequencing of ribosomal DNA. Sequencing of ITS (Internal Transcribed Spacer) and the 5.8 s rDNA is straightforward and provides a basis for species identification. The sequences were searched for by means of BLAST (Basic Local Alignment Search Tool) in the GenBank. The PCR technique will be an important step in the future both toward detecting fungal infestations at an early stage because of the ability to detect specifically the infestation without time-consuming cultivation in the laboratory and allowing reliable species identification based on sequences obtained from databases.

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