Mold detection in the domestic indoor environment: preliminary results from Luxembourg

In Luxembourg, various climate models indicate changes in seasonal precipitation with decrease of rainfall events in summer and increase in winter with more frequent and intense storms and floods. These extreme weather conditions could affect the building's structure, allowing water to infiltrate indoor. Within the national indoor monitoring program 2021, we have received 43 medical requests to sample and identify molds and yeasts of household's indoor air, suspected of causing health problems for their residents. A total of 251 samples were analyzed and showed that concentration of fungi was up to 10 times higher indoors than outdoors in 75% of visited houses (especially for Aspergillus flavus, A. fumigatus and molds of Cladosporium and Penicillium genera). Relative humidity levels ≥ 60% were observed in 50% of houses, which is known to promote mold and fungi development. Microorganisms detected in domestic environments of Luxembourg correspond to common biological contaminants of European houses.