Indoor environmental problems and health status in water-damaged homes due to tsunami disaster in Japan

• Indoor environmental problems were observed in flood-damaged homes after flooding.
• Persistent health problems were recognized within six months after flooding.
• Mould growth after flooding was observed at least for one year.
• Exposure to poor environment was positively associated with adverse health effects.

The Great East Japan Earthquake occurred on March 11, 2011. The resulting tsunami caused extensive damage in seaside cities along the Pacific coast of the Tohoku district of Japan. The long-term presence of water in crawl spaces and wall cavities causes elevated humidity and fungal contamination, with potential implications for affecting the health of the occupants. In order to clarify the actual indoor environment and occupants' adverse health effects, a cross-sectional study in the flood-damaged homes located in the flooding areas was conducted from July to December of 2012. We randomly selected 234 dwellings, and a total of 170 responses were obtained for a main survey (Phase 2). Indoor environmental problems related to dampness and mould growth were observed in flood-damaged homes after the flooding. Exposure to poor indoor environmental quality after flooding was positively associated with adverse health effects. Persistent health and environmental problems were recognized within six months after flooding and the long-term effects of mould growth after flooding was observed at least for one year.