The cause of sick house syndrome is volatile organic compound gas (VOC gas).
The photocatalyst decomposed/detoxifying harmful gases as well as deodorizing effects.
In the case of a new house, there is no problem basically because building materials are adopted after strict inspection, but there are many cases where a sick house develops after entering, and the cause is said that imported furniture or sofas etc. However, VOC gas that has volatilized once adsorbs in the room, and then it gradually diffuses and affect the human body. If you coat the whole room with a visible light reaction type photocatalyst before moving in, it is safe because the emitted VOC gas continues to be decomposed. However, it does not work in a state where the light does not enter and shutting the door, window completely. Immediately after entering a new house, ventilate well, open the curtains and receive light as much as possible to maximize the photocatalyst activity.