Prevention strategy against fungal attack using selected fungi as biologic sensors

Purpose / Context - The purpose of this study was to develop a prevention strategy against fungal attack in any residential building, which had been previously proposed and applied to conserve cultural assets using a fungal index. The strategy consisted of four stages: current status assessment, diagnosis, preventive measures, and finally confirmation of the preventive measure. In the current status assessment, the microclimates in a target room are to be evaluated firstly using the fungal index, which assesses the environmental conditions critical for fungal growth. The microclimates are diagnosed and categorized into the following three levels: A (free of contamination), B (probable contamination), or C (unavoidable contamination), depending on the index values 18, respectively. Suitable preventive measures are to be adopted at the sites with level B or C. After implementing the preventive measures, the fungal indices ought to be measured again for the evaluation of the employed preventive measure as well as the confirmation of level A. Methodology / Approach – One storeroom was selected as a target room to apply the approach, as a case study of the prevention strategy against fungal attack, including the diagnosis using fungal index values at the sites of interest, selection of a preventive measure, and the subsequent confirmation of the preventive measure. Results – Fungal index measurements throughout a period of one year as a current status assessment revealed that the microclimates in the target room were level B only in winter. As a preventive measure, a commercially available dehumidifying system was selected and installed in the target room. Fungal-index measurements confirmed that the room conditions had changed from level B to level A. Key Findings / Implications - The cause of level B in the target room was moisture invasion from the neighboring storeroom which had been air-conditioned at 20°C and 55% RH year-round, warmed and humidified in winter. The preventive measure implemented has completely suppressed fungal growth in the target room. This practical application of the strategy was successful. Originality - The phenomenon of moisture moving from warm and humidified rooms to cold and non-humidified ones will occur in any residential building in winter, resulting in mold contamination of cold wall surfaces. However, the systematic use of a fungal detector and fungal index will make the quantitative diagnosis of dampness possible, followed by the selection of a suitable preventive measure.