Airborne fungal ecological niche determination as one of the possibilities for indirect mycotoxin risk assessment in indoor air.
Based on the microbiological analysis of air samples from occupied spaces, some possibilities for indirect risk assessment of mycotoxin-related health problems are proposed. Airborne fungi could be classified on the basis of the relationship between the two environmental factors and their combinations, i.e., temperature and water requirements (water activity aw). One type involves three different groups of molds, selected on the basis of the quantitative and qualitative information about the ability of fungi to sporulate under different environmental conditions: group (i), represented by Aspergillus nidulans, A. niger, and A. ochraceus, and characterized by sporulation which was more dependent on temperature than on water activity; (ii), represented by A. flavus and A. versicolor, in which sporulation was approximately equal and depended on both the temperature changes and aw alterations; and (iii), represented by Cladosporium sp., Penicillium cyclopium, and P. citrinum, in which sporulation depended more on alteration of the aw conditions than on temperature changes. Another type is characterized by four sporulation rates with two levels of mycotoxin risk accumulation in the spores (conidia) of each mold species: large (Ia) and moderate (Ib) sporulation rates with a risk of mycotoxin accumulation (aw > or = 86; t > or = 12 degrees C); rare sporulation (IIa) and absence of sporulation (IIb), without risk of mycotoxin accumulation (aw < or = 86; t < or = 12 degrees C). In conclusion, providing a useful guide for two dimensions, temperature and water activity for each of the three phases of fungal growth, i.e. germination, growth, and sporulation, could be important for determination of the fundamental niche of each fungus and its ability to form or accumulate mycotoxin. Special emphasis should be given to the indirect mycotoxin risk assessment in heating, ventilation, and air conditioning systems.
Vujanovic
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Institute de recherche en biologie végétale et Département de sciences biologiques, Université de Montréal, 4101, rue Sherbrooke East, Montréal, Québec, Canada H1X 2B2. vujanovv@magellan.umontreal.ca
Smoragiewicz
W
W
Krzysztyniak
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K
D016604:Aflatoxin B1 / Q000032:analysis; D000348:Aflatoxins / Q000032:analysis; D000391:Air Microbiology; D016902:Air Pollution, Indoor; D005658:Fungi / Q000254:growth & development / Q000302:isolation & purification*; D009183:Mycotoxins / Q000032:analysis*; D018570:Risk Assessment; D013172:Spores, Fungal / Q000502:physiology
D000348:Aflatoxins; D009183:Mycotoxins; C027955:aflatoxin G1; D016604:Aflatoxin B1