APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 0099-2240/00/$04.00+0 May 2000, p. 1899–1904 Vol. 66, No. 5 Copyright © 2000, American Society for Microbiology. All Rights Reserved. Mycotoxins in Crude Building Materials from Water-Damaged Buildings TAPANI TUOMI, 1 * KARI REIJULA, 1 TOM JOHNSSON, 1 KAISA HEMMINKI, 2 EEVA-LIISA HINTIKKA, 1 OUTI LINDROOS, 1 SEIJA KALSO, 3 PIRKKO KOUKILA-KA ¨ HKO ¨ LA ¨ , 4 HELENA MUSSALO-RAUHAMAA, 5 AND TARI HAAHTELA 5 Finnish Institute of Occupational Health (FIOH), Uusimaa Regional Institute, FIN-00370 Helsinki, 1 City of Vantaa Environment Center, FIN-01300 Vantaa, 2 City of Helsinki Environment Center, FIN-00530 Helsinki, 3 and HUCH Diagnostics, Mycological Laboratory, 4 and Department of Dermatology and Allergic Diseases, 5 Helsinki University Central Hospital, FIN-00250 Helsinki, Finland Received 7 September 1999/Accepted 1 March 2000 We analyzed 79 bulk samples of moldy interior finishes from Finnish buildings with moisture problems for 17 mycotoxins, as well as for fungi that could be isolated using one medium and one set of growth conditions. We found the aflatoxin precursor, sterigmatocystin, in 24% of the samples and trichothecenes in 19% of the samples. Trichothecenes found included satratoxin G or H in five samples; diacetoxyscirpenol in five samples; and 3-acetyl-deoxynivalenol, deoxynivalenol, verrucarol, or T-2-tetraol in an additional five samples. Citrinine was found in three samples. Aspergillus versicolor was present in most sterigmatocystin-containing samples, and Stachybotrys spp. were present in the samples where satratoxins were found. In many cases, however, the presence of fungi thought to produce the mycotoxins was not correlated with the presence of the expected compounds. However, when mycotoxins were found, some toxigenic fungi usually were present, even if the species originally responsible for producing the mycotoxin was not isolated. We conclude that the identification and enumeration of fungal species present in bulk materials are important to verify the severity of mold damage but that chemical analyses are necessary if the goal is to establish the presence of mycotoxins in moldy materials. Mycotoxins are “natural products produced by fungi that evoke a toxic response when introduced in low concentrations to higher vertebrates by a natural route” (J. W. Bennett, Ed- itorial, Mycopathologia 100:3–5, 1987). These compounds can cause a wide range of acute and chronic systemic effects in humans and animals that cannot be attributed to fungal growth within the host or allergic reactions to foreign proteins (22). The over 400 known mycotoxins are all complex organic com- pounds, most with molecular masses between 200 and 800 kDa (40), that are not volatile at ambient temperatures. Inhalant exposure to mycotoxins can occur by inhaling airborne partic- ulates containing mycotoxins, including dust and fungal com- ponents. In agricultural settings, mycotoxicoses in both farm animals and humans can result from oral, dermal, or inhalant exposure of mycotoxin-contaminated grain or dust (for re- views, see references 4, 11, 12, 23, 36, 38, and 41). In laboratory mammals, symptoms can be induced by systemic, oral, dermal, subcutaneous, or inhalant exposure (25, 44), with inhalant ex- posure in some cases being several orders of magnitude more toxic than dermal or even systemic administration (13, 32, 34). Toxigenic fungi have been isolated from building materials and air samples in buildings with moisture problems, where the residents have suffered from nonspecific symptoms possibly related to mycotoxin production, such as cough; irritation of eyes, skin, and respiratory tract; joint ache; headache; and fatigue (3, 8–10, 24, 27, 29, 37, 39). In some cases involving Stachybotrys chartarum (Ehrenberg ex Link) Hughes, exposure has resulted in pulmonary hemorrhage (8–10), and S. charta- rum isolates from such sites have been shown to produce a number of mycotoxins, including satratoxins (26). Very few studies have, however, established a causal relationship be- tween mycotoxin exposure and building-related illnesses (re- viewed in reference 19). All known mycotoxins are fungal secondary metabolites, which means that mycotoxin production need not be correlated with the growth and proliferation of the producing species and that factors such as induction, end product inhibition, catabo- lite repression, and phosphate regulation will determine pro- duction (6, 7). Therefore, even though some fungi can grow on almost any natural or synthetic construction material, myco- toxin production occurs preferentially on materials that both allow these fungi to grow and provide the conditions for my- cotoxin production. From the many studies of the production of mycotoxins by fungal isolates derived from agricultural en- vironments, a great deal is known about the fungal species that are capable of producing known mycotoxins and about the growth media and conditions that induce production (5, 14, 25, 28). It is known that some species include strains that produce mycotoxins and others that lack this ability (6, 7). It also has been established that many of the known mycotoxin producers are frequent colonizers in indoor environments (30, 35, 37). Less is known, however, about the presence of mycotoxins in indoor environments, and it is only in recent years that the presence of some mycotoxins has been verified in crude build- ing materials (1, 14, 21, 27, 40, 41a). In fact, most mycotoxins have yet to be extracted from either air samples or bulk ma- terial derived from indoor environments. Satratoxins belong to the macrocyclic trichothecene class of mycotoxins. Over 100 trichothecenes with irritatory and immu- nosuppressive effects are known (43). Most trichothecenes were originally isolated from species of Fusarium, but they also * Corresponding author. Mailing address: Finnish Institute of Oc- cupational Health (FIOH), Uusimaa Regional Institute, Arinatie 3 A, FIN-00370 Helsinki, Finland. Phone: 358-9-4747926. Fax: 358-9- 5061087. E-mail: tapani.tuomi@occuphealth.fi. 1899