Indoor air fungal pollution of a historical museum, Egypt: a case study

Fungi can cause serious damages to historical works of art. This study aims to evaluate fungal pollution in the indoor air environment, deposited dust and surfaces of works of art in a historic house museum "Prince's Mohamed Ali museum", Giza, Egypt. Fungal pollution was evaluated at six museum's buildings differed in size, design, location and content, for 2 years of campaign. The deposited dust was collected once every 3 months, while surface swabs were collected twice, after 1 year and 2 years of exposure. Airborne fungal concentrations were evaluated using volumetric (Andersen 2 stage impactor) and gravimetric (index microbial air contamination) air samplers. Airborne fungal concentrations ranged within 47-784 CFU/m(3) and 175-40,250 CFU/m(2)/h using volumetric and gravimetric samplers, respectively. Indoor/outdoor ratio confirmed that outdoor environment was the main source of indoor fungal pollution. The rate of deposited dust was similar to 90-folds lower indoor than outdoor. Fungal concentrations associated deposited dust ranged between 10(2) and 10(4) CFU/g, representing a cause of concern. In respect to medium type, fungal diversity profile was in order of deposited dust >= airborne >= surfaces. Alternaria, Aspergillus and Cladosporium were the common fungal taxa. Secondary and tertiary fungal colonizers were detected after 2 years of exposure, indicating the presence of adequate moisture content inside the museum. No clear relationship patterns were found between microclimatic conditions and fungal culturability. The measured indoor fungal pollution and microclimatic conditions represented a problem for works of art and early indicator for fungal accumulation and biodegradation.