An experimental verification of fungal overgrowth in temporary houses at the site of the Great East Japan Earthquake.

Fungal contamination in the indoor air of prefabricated temporary houses at the site of the Great East Japan Earthquake revealed extremely high levels compared to those found in conventional residences. We experimentally investigated fungal growth levels on different interior materials to support fungal overgrowth in prefabricated temporary houses. Three species each of allergenic fungi and invasive fungi observed in temporary housing were selected for inoculation tests with various interior materials. The experiments with fungal inoculation were conducted in conformance with standards for industrial products described in the Japanese" JIS Z 2911:2018 Methods of test for fungus resistance" with small modifications. After incubation, visual and stereomicroscopic assessments were performed to determine fungal growth levels. The viability of the fungi varied according to the interior material type. Our findings demonstrate the importance of antifungal measures in indoor environments and the need for additional research on the growth levels of fungal species on various interior materials.