title: Airway toxicity of house dust and its fungal composition.
abstract: House dust is an important source of different toxic metabolites as well as allergens, including those of fungal origin, in the indoor environment. A bio-assay employing 1-day-old chick tracheas was used to characterize airway effects of 2-butanone and dimethylsulphoxide (Me2SO) extracts of 23 dust samples collected from water damaged (13) and control (10) Danish schools. Direct microscopical analysis of samples, followed by cultivation on dichloran 18 % glycerol agar at 25 degrees C for 10 days to establish their mycoflora, was performed. The in vitro ciliostatic potential of the chloroform-extractable endo- and exometabolites of 41 representative fungal isolates was determined. Nine dust extracts in 2-butanone (2 from damp rooms) or 10 (6) in Me(2)SO showed some ciliostatic activity in the 3-days' experiment. Fungal composition of dust from buildings with leakage was almost identical with that from undamaged houses, as well as the fungal colony counts from the damp schools and the control samples. Aspergillus spp. were prevalent in the samples - 31 or 40 % of all fungi, followed by Penicillium spp. and Cladosporium cladosporioides. Alternaria spp., Chaetomium spp., Mucor spp., Mycelia sterilia, Paecilomyces variotii, Rhizopus sp., Ulocladium sp. and yeasts were each isolated in less than 8 % of the fungal content. No Aspergillus flavus isolate (8 in total) was aflatoxigenic,em>in vitro. Alternaria spp., Aspergillus spp., Botrytis cinerea, Penicillium spp., C. cladosporioides, Chaetomium spp. and Ulocladium sp.; in total, 88 % of all fungi tested, produced ciliostatically active metabolites. These toxigenic strains were also present in 4 dust samples from controls and 5 dust samples from water damaged buildings. Extracts of these dust samples were also toxic in bioassay. There were bio-detectable concentrations (10-20 microg of extracts/ml of the organ culture medium) of toxic compounds in house dust. Contribution of fungal metabolites to its toxic effect should be studied further.
authors.affiliation: Research Base of the Slovak Medical University-Institute of Preventive and Clinical Medicine, Limbova 12, SK-833 03 Bratislava, Slovakia. pieckova@upkm.sk
authors.forename: Elena
authors.initials: E
authors.lastname: Piecková
authors.forename: Ken
authors.initials: K
authors.lastname: Wilkins
mesh_terms: D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000032:analysis*; D000818:Animals; D001681:Biological Assay / Q000379:methods; D002074:Butanones; D002645:Chickens; D002648:Child; D002669:Child Welfare; D003718:Denmark; D004121:Dimethyl Sulfoxide; D004391:Dust; D005658:Fungi / Q000302:isolation & purification* / Q000378:metabolism; D006794:Household Articles / Q000592:standards; D006801:Humans; D009181:Mycoses / Q000382:microbiology; D009183:Mycotoxins / Q000096:biosynthesis / Q000633:toxicity; D009924:Organ Culture Techniques / Q000379:methods; D013997:Time Factors; D036401:Toxicity Tests, Chronic; D014132:Trachea / Q000378:metabolism
chemical_list: D002074:Butanones; D004391:Dust; D009183:Mycotoxins; C005222:methylethyl ketone; D004121:Dimethyl Sulfoxide