Over the last 30 years in Japan, there has been a 10% increase in the number of people suffering from sick house syndrome due to toxic chemicals released from construction materials and wallpaper. This syndrome can develop into the more complex and disabling, chemical sensitivity syndrome, so preventing early exposure to toxins at home is critical in reducing the likelihood of health problems in the community. A qualitative study was undertaken using ethnographic methods to identify the psychosocial aggravating factors of sick house syndrome. As a result, the participants identified three aggravating factors that extended the period of exposure of the participant to toxic chemicals: a lack of knowledge about the disorder; the difficulty in establishing a diagnosis; and the difficulty of taking radical measures to improve the home environment. Public awareness of sick house syndrome and the dangers of toxicity from construction materials is vital to eliminate these aggravating factors and to prevent illness.