[Hygiene in Sleep: Problems of Sleeping Habits in Shift Workers].

Since World War II, Japan has achieved remarkable economic development and has become an advanced country. Particularly in the industrial field, a production system has been developed to reduce the loss of machining time by adopting a shiftwork in factories operating 24 hours a day, which contributes to the improvement of productivity. Nowadays, this shiftwork practice has spread from the industrial field to other businesses such as 24-hour entertainment facilities and convenience stores, which lead to sleep deprivation in Japanese society. Even at home, certain conditions adversely affect sleeping habits. We are concerned about the risks of physical and mental health, impairments posed by the use of tablets, PCs, smartphones, and other devices so popular in today's Japan, as they delay sleep. It is urgent to improve poor sleeping habits because their outcomes such as sleep disorders and deprivation may also lead to traffic and industrial accidents.