engleski

The aftermath of flood: diversity of fungal toxic metabolites in the house dust in Croatia

Background: In the past decade we are witnessing the rising occurrence of climate extremes all around the world. Droughts, hurricanes, storms and floods are life threatening and with multiple consequences including economic loss and health hazards. Changes of temperature and water availability also affects fungi and their metabolic profile. Post-flood mould colonisation of indoors may represent health threat to inhabitants due to inhalation and cutaneous exposure to fungal allergens and toxic metabolites. Vacuumed dust sampling may be more representative in terms of human exposure indoors as they act as a sink for airborne moulds and their secondary metabolites. Aims and scope: In spring 2014 heavy rainfall and floods have been experienced in the Eastern Croatia. In this study we aimed to characterize the presence of fungal toxic metabolites in house dust in association with the post-flood water damage. Materials and Methods: Samples of house dust were collected in winter and summer of 2016 and 2017 in repaired and unrepaired houses in Gunja (flooded village ; 44°53′48″N 18°51′0″E) and Gornji Stupnik (control village ; 45°46′01″N 15°51′00″E). A 30 mg subsample of dust collected from five houses at each location in each sampling period (N= 60) was used for the secondary metabolite analysis. Metabolites were extracted and diluted from dust using acetonitrile/water/acetic acid solution and analysed by HPLC System coupled to a QTrap 5500 equipped with Turbo Ion Spray ESI source in connection with a Gemini C18 column (150 x 4.6 mm i.d., 5 µm particle size). Results: More than hundred different metabolites, namely Aspergillus, Penicillium, Alternaria and Fusarium metabolites were detected in dust samples. Among these dominated metabolites produced by Aspergilli. Sterigmatocystin (STC) and its precursors were frequently detected in repaired houses in flood affected and control area (from 3.8 ± 1.2 ppb to 73.9 ± 138.4 ppb and 1.8 ± 0 ppb to 20.7 ± 39 ppb, respectively). Stachybotrys metabolites stachybotryamide and stachybotrylactam were detected only in one sample from the flood affected area (73.6 and 435.6 ppb, respectively). Conclusion: No specific metabolic profile associated with post-flood water damage was identified. However, exceptionally high concentrations of STC and Stachybotrys metabolites at the certain locations in flooded village suggest thorough remediation in order to prevent possible health hazards. Acknowledgements: This work has been fully supported by Croatian Science Foundation under the project MycotoxA (IP-09-2014-5982).

dust ; fungal metabolites ; flood

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