Detection of Airborne Stachybotrys chartarum Macrocyclic Trichothecene Mycotoxins in the Indoor Environment
T. L. Brasel, J. M. Martin, C. G. Carriker, S.C. Wilson and D.C. Straus*Department of Microbiology and Immunology, Texas Tech University Health SciencesCenter, Lubbock, TX 79430.
*Corresponding author. Mailing address: Department of Microbiology and Immunology,TTUHSC, 3601 4th St. Lubbock, TX 79430Phone: (806) 743-2523Fax: (806) 743-2334Email:
2 The existence of airborne mycotoxins in mold-contaminated buildings has long
3 been hypothesized to be a potential occupant health risk. However, little work has been
4 done to demonstrate these compounds in such environments. The presence of airborne
5 macrocyclic trichothecene mycotoxins in indoor environments with known Stachybotrys
6 chartarum contamination was therefore investigated. In seven buildings, air was
7 collected using a high volume liquid impaction bioaerosol sampler (SpinCon PAS 450-
8 10) under static or disturbed conditions. An additional building was sampled using an
9 Andersen GPS-1 PUF sampler modified to separate and collect particulates smaller than
10 conidia. Four control buildings (i.e., no detectable S. chartarum growth or history of
11 water damage) and outdoor air were also tested. Samples were analyzed using a
12 macrocyclic trichothecene-specific enzyme-linked immunosorbent assay (ELISA).
13 ELISA specificity was tested using phosphate buffered saline extracts of the fungal
14 genera Aspergillus, Chaetomium, Cladosporium, Fusarium, Memnoniella, Penicillium,
15 Rhizopus, Trichoderma, five Stachybotrys strains and the indoor air allergens Can f 1,
16 Der p 1, and Fel d 1. In test buildings, results showed that detectable toxin
17 concentrations increased with sampling time and short periods of air disturbance.
18 Trichothecene values ranged from less than 10 to greater than 1300 pg/m3 of sampled air.
19 The control environments demonstrated statistically significant (P<0.001) lower levels of
20 airborne trichothecenes. ELISA specificity experiments demonstrated a high specificity
21 for the trichothecene-producing strain of S. chartarum. Our data indicate that airborne
22 macrocyclic trichothecenes can exist in Stachybotrys-contaminated buildings and this
23 should be taken into consideration in future indoor air quality investigations.
Our study shows that macrocyclic trichothecene mycotoxins from Stachybotrys
4 chartarum can become airborne in indoor environments contaminated with this organism.
5 Our data suggest the need to test for these potential occupant health risks during indoor
6 air quality investigations. Although we were able to semi-quantitate airborne
7 concentrations, it is still not known what levels of these mycotoxins pose a definitive
8 human health risk. Additionally, normal background levels (if they do exist) have not
9 been characterized. Future research should focus on the relationship between respiratory
10 exposure to airborne trichothecenes in fungal-contaminated buildings and human health
11 issues resulting from such exposures.