Light exposure at night plays a role in sleep problems among children. However, the association of daytime and nighttime light exposure with melatonin secretion and sleep quality in children’s daily natural environments remains unknown in Japan. The aim of this cross-sectional study was to preliminarily evaluate the association of light exposure, including the illuminance ratio during the daytime and nighttime, with melatonin secretion and sleep quality in 10 children (mean ± SD age 4.9 ± 1.1 years) at home setting. In this study, the participants were visited their home and asked to complete questionnaires, measure daytime and nighttime light exposure, record sleep diaries and collect urine samples. The illuminance logger measuring nighttime light exposure was measured for three consecutive nights, while the actigraph measuring daytime light exposure was measured for seven consecutive days. Urine samples were collected on the morning of the second day, and the urinary 6-sulphatoxymelatonin concentration, an indicator of melatonin secretion, was calculated. The results showed that daytime light exposure was positively correlated with melatonin secretion and sleep efficiency, and negatively correlated with the number of awakenings during the night. These results suggest that daytime light exposure may be associated with melatonin secretion and sleep quality when nighttime light exposure is low, and that it is necessary to understand children's sleep problems from the perspective of the light environment.

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Purpose: In this study, we compared the effects on stiff neck and shoulder symptoms and sleep when using their own pillow (Baseline Pillow : BP) and our developed cervical-thoracic alignment-supporting pillow (Test Pillow : TP). Method: participants who were not fully satisfied with their sleep and stiff neck and shoulder symptoms were recruited. Twenty-nine people (males: 13, females: 16, age: 53.5 ± 7.1 years old) were selected who had heavy neck and shoulder stiffness symptom and Pittsburgh Sleep Quality Index (PSQI). The study was performed for two periods, each of which was a week of BP and TP. Participants were asked to perform questionnaires about degree of stiffness in neck and shoulders and sleep sensation (Karolinska Sleepiness Scale (KSS), Numerical Rating Scale (NRS) at home for themselves during two weeks. After each period, muscle hardness measurement and sleep questionnaires (OSA sleep inventory MA version (OSA-MA)) were performed. Result: TP significantly reduced the degree of subjective symptoms such as stiff neck and shoulders compared to BP. The subjective sleep quality (KSS, NRS) with TP was significantly lower than that with BP. OSA-MA (falling asleep and staying asleep, fatigue recovery and sleep duration) with TP was significantly higher than that with BP. Muscle hardness showed no significant difference between BP and TP. Conclusions: This study suggested that the TP may have reduced subjective symptoms of neck and shoulder stiffness and improved sleep sensation in participants with stiff neck and shoulder symptoms on awakening.

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This study reviewed the effects of environmental noise, primarily traffic noise, on sleep and health. Indirect effects of traffic noise include sleep disturbance, insomnia, and stress reactions in the autonomic nervous system and endocrine system, leading to progression to lifestyle-related diseases such as hypertension and heart disease. The effect of road traffic noise on sleep EEG is a reduction in REM sleep. The effect of intermittent track-passing noise on sleep EEG was a significant decrease in the number of spindles at a peak sound level of 45 dB, and the delta wave % decreased at a peak sound of 55 dB. Adult women living along major road with nighttime noise levels of Leq 65 dB(A) have about three times risk of insomnia. Adults living near US military bases with a Lnight 50 dB(A) or higher have a 2.5 times risk of insomnia. WHO recommendations are 45 dB for road traffic noise and 40 dB for aircraft noise. Environmental standards are established through criteria and guidelines such as technical, social, and economic considerations, coordination of related organizations, and administrative judgments and decisions. In order to minimize the health effects of environmental noise, further research and countermeasures against noise sources are necessary.

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When measuring sleep status, both objective and subjective sleep parameters are used. In particular, Subjective sleep variable is an extremely important assessment tool to capture changes in the psychological state of the individuals complain with sleep disturbances, since the subjective evaluation reflects the "worries and distresses " of them. This paper describes sleep diaries and self-reported scales as subjective sleep parameters. The sleep diary is used to "visualize " the daily changes in the sleep state of the patient. It is recommended as the gold standard for assessing subjective sleep state. The self-reported scales are a relatively simple way to measure changes in sleep problems. In particular, the Pittsburgh Sleep Quality Index (PSQI) and the Athens Insomnia Scale (AIS) are the gold standard for measuring sleep quality and insomnia symptoms and have been translated in many countries. In addition, the Epworth Sleepiness Scale (ESS) and Restorative Sleep Questionnaire (RSQ), which measure sleepiness and restfulness as daytime symptoms, were also described. Finally, the importance of combining not only subjective but also objective sleep assessment tools was discussed.

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This review outlines an attempt to improve the sleep satisfaction of Toyama residents with government agencies. Women’s sleep satisfaction and men’s lack of exercise are the lowest among the 47 prefectures in 2018 of Toyama Prefecture. The percentage of people with high blood sugar exceed the national average for both men and women. Therefore, the government first attempted to improve sleep habits to improve health by improving the lifestyle habits of the prefecture’s citizens. In 2021, in order to improve sleep habits, companies and family members formed teams and worked on improving sleep. So, we set nine lifestyle behavior goals to improve sleep. A total of 243 teams ( 1,352 people ) took on the challenge of improving their living behavior for three weeks. Actions that made it easier to continue were having an early dinner, drinking a glass of water before going to bed, and opening the curtains upon waking up. Teams of 8 or 9 people working to improve their lives had the best rate of improvement. From this, it was suggested that improvement effects can be achieved when efforts are made by individual departments or by the entire company rather than by a small number of people.

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