Climate change is continuing to progress steadily, and without effective greenhouse gas emission controls, the temperature rise at the end of this century is projected to reach roughly 4.3℃, compared to before the Industrial Revolution. Climate change not only results in a rise in average temperature, but also causes an increase in extreme phenomena such as heat waves and heavy rains, and a variety of adverse health effects are expected. In this paper, I summarize the health chapter of the Ministry of the Environment's Climate Change Impact Assessment Report released in December 2020, and explain suggested adaptation measures in Japan.

In Japan, the risk of death from heat stress or heat stroke is particularly high as a health risk associated with climate change, and adaptation measures to meet this risk are urgently needed. Without proper measures, the number of heat-related excess deaths in the middle and end of this century is expected to more than double that in 2010 in all 47 prefectures, irrespective of greenhouse gas emission scenario. In addition, the risk of domestic epidemics of arthropod-borne infectious diseases such as dengue fever is particularly high, and adaptation measures to meet this risk are also urgently needed. The risk of increased incidences of water-borne and food-borne infectious diseases has also been projected.

The Climate Change Adaptation Law was enacted in 2018, and it will be necessary for society to promote adaptation measures to minimize associated impacts on public health. It is also critical to assess whether the current health care system will be capable of meeting the community's medical needs and maintaining health standards, even under future scenarios involving these adverse health impacts. In addition, it is also recommended to pursue co-benefits that promote mitigation measures, while simultaneously promoting health. Human health should always be prioritized in promoting adaptation measures.

The most important direct health risk due to climate change in Japan, one of the developed countries, is heat-related mortality. “Heat-related mortality” is defined in the following manner. There exists a temperature at which the daily mortality risk is at its lowest. This temperature is referred to as the “optimum temperature” or “minimum mortality temperature.” When the daily temperature exceeds the optimum temperature, mortality increases. This added mortality is called heat-related excess mortality, or simply heat-related mortality. In terms of causes of death, heat-related mortality includes circulatory diseases and respiratory diseases, while heatstroke is responsible for less than 1% of heat-related deaths. Heat-related mortality has the following features: 1)the risk in earlier summer is higher than that in later summer; 2) the contribution due to other weather variables, such as humidity and wind speed is small; 3) vulnerable populations include children and the elderly; and, 4) the optimum temperature is lower in colder areas than in warmer areas. For adaptation measures, the appropriate use of air-conditioners and drinking water are the two most important items. Due to both population aging and COVID-19, it is becoming more difficult to adapt to hotter summers, and measures that are tailored for individual municipalities are necessary.

Climate change is a significant threat to human health around the world, and represents one of the most important challenges for public health. There is a growing concern that climate change has an impact on the geographical distribution, seasonality, and epidemic scale of emerging and re-emerging infectious diseases, due to a variety of extreme weather events caused by changes in temperature, as well as a worsening of air pollution caused by climate change.

Climate change affects the incidence and distribution of infectious diseases. The impact of climate change varies by region, and the Western Pacific and Asia region has been more susceptible to climate change than other regions. Further, the risk of infectious diseases due to climate change is not uniform, and may vary by pathogen and region.

Socio-environmental and economic factors, as well as individual socio-economic and behavioral factors play an important role in vulnerability to climate change. It has been reported that promoting public health policies and programs, such as the development of adaptation and mitigation strategies for climate change, enhanced surveillance of infectious diseases, provision of air conditioning in public facilities, improvement of medical and health services, drainage measures, construction of seawalls, and reforestation may have resulted in a reduced vulnerability to climate change. The possibility of differences in the effects of public health policy between diseases and regions should be kept in mind.

In the future, people's lifestyles and values will become more diverse across generations. There are also concerns that health inequalities will increase as the population ages. The implementation of mitigation and adaptation strategies, and public health policies for climate change is essential to reduce the disease burden of infectious diseases caused by climate change. Contributing to the promotion of public health policies and a strengthening of public health systems based on regional and population characteristics, through the accumulation of higher-quality scientific evidence is an important task.

Water supply systems are affected in various ways by climate change, in terms of water quality, quantity, and facilities. The effects on water quality include taste and odor problems due to algae growth, increased concentrations of disinfection byproducts due to increased concentrations of their precursors, high turbidity due to flooding, and salt contamination in raw water due to salt water run-ups. In recent years, heavy rainfall and typhoon-related flooding have caused extensive damage to water supply facilities, leading to large-scale water outages. As the water supply systems represent infrastructure lifelines, water cut-offs result in serious damage to the lives and business activities of people. In addition, droughts have also caused water cutoffs every year. A variety of adaptations were applied to meet these effects. General adaptations include the identification of hazards to the water supply systems, risk assessment, and vulnerability assessment (e.g., flood risk maps and drought risk maps). In the case of water quality, although the adaptations that are applied depend upon the specific water quality issues, watershed management at the water source, as well as treatment at the water purification plant were mentioned. For floods and droughts, both intangible adaptations such as the emergency water supply systems and tangible adaptations, such as the installation and renewal of facilities were applied. While these adaptations have been implemented in practice, it is also important to develop a water supply management plan and a water safety plan that properly take the impacts of climate change into account. In order to assess these impacts, it is necessary to continuously monitor target items and work to achieve their enhancement, while utilizing predictive data on climate change.

Architectural structures have traditionally served as shelters to protect the lives and health of residents from external disturbances and enemies, and today should ensure not only health and hygiene, but also the comfort of occupants.

Climate change due to global warming and increasing concentrations of greenhouse gases has brought about extreme temperature changes, heavy rains and snowfalls, typhoons, and other natural threats.

Currently, our society is asking the architecture and construction field to address a conflicting and difficult situation, which involves not only saving energy and resources, but also providing more comfortable and healthy indoor environments.

The impacts of climate change and global warming on the architecture field range from implications for smart cities, to details regarding the high performance of buildings and new equipment technologies, including HVAC in large indoor environments, in terms of temperature, humidity, air quality, and ventilation.

In fact, energy saving, either directly or indirectly, accounts for a deterioration of indoor environments such as air quality, ventilation rate, and relative humidity. Energy conservation in buildings, however, does not merely aim at achieving high efficiency and savings, and is the basis for securing a comfortable, hygienic, and healthy indoor environment for residents.

For that purpose, the architecture field is attempting to develop and improve technologies for construction, equipment, and operations, and is nowadays broadly engaged in innovation, from occupant literacy to work-life styles.

The surface air temperature in Japan is continuing to rise, as evidenced by the temperature observations that have been made since the 1890s. This rise in temperature is due not only to urbanization, but also to global warming. Against this background, efforts to adapt to climate change are now underway in Japan.

With the establishment of the national climate change adaptation plan in 2015 and the enactment of the national climate change adaptation law in 2018, the development of adaptation plans by local governments is progressing steadily. In part, this may be due to support provided to local governments by the national project to develop such adaptation plans, the launch of the Climate Change Adaptation Information Platform by the Ministry of the Environment, and the ease of access to information regarding climate change adaptation.

This paper describes the current status of climate change adaptation planning by Japanese local governments. As a concrete example of such local activities for climate change adaptation planning, we describe the countermeasures for climate change adaptation that have been taken in the thermal environment sector in Saitama Prefecture.

Purpose: To investigate the effects of blue light exposure before bedtime on subjective sleep quality, attention, and work efficiency in young men without sleep disturbances.

Methods: A total of 12 young men (aged 20–23 years) without sleeping disorders were exposed to two conditions: 1) incandescent lamp and 2) blue light for 1 h before bedtime. The sleep status was monitored using a mat-type sleepmeter. The next morning after exposure, subjective sleep quality, attention, and work efficiency were measured. Subjective sleep quality was measured using the Oguri-Shirakawa-Azumi sleep inventory (MA version), attention using the psychomotor vigilance task, and work efficiency using the Purdue Peg board.

Results: This study revealed no significant difference in the subjective sleep quality between two conditions of incandescent lamp and blue lights. Additionally, sleep duration remains unchanged; however, the rate of deep sleep was significantly reduced. Work efficiency was also significantly reduced with blue light compared to incandescent lamp. Moreover, the reaction time of blue light attention significantly extended in the last 5-min of the 10-min measurement time.

Conclusion: The results of this study suggest that blue light exposure before bedtime may reduce an individual’s attention and work efficiency on the following day.

Objectives: Owing to the rapid growth in the aging population, it is considered important to develop models and assessment instruments on social care. The Japanese version of the self-completion adult social care outcomes toolkit (ASCOT) was developed to measure Social Care Related Quality of Life (SCRQoL). This study aimed to identify (1) the distribution of SCRQoL measured by ASCOT-SCT4(ASCOT four-level self-completion questionnaire), and (2) the variables related to SCRQoL by analyzing data obtained from community-living elderly people with long-term care needs in Japan.

Methods: Data comprised responses of 819 people who were 65 years old or over, and who were using long-term care services at the time of this survey from those of 1141 people living in a municipality near the Tokyo metropolitan area. Responses to the ASCOT-SCT4 were converted to SCRQoL scores. A multiple regression analysis was performed to determine the factors related to the scores. The following two models were extracted: Model 1 comprised sex, age, care level, self-rated health, solitary or living together with someone, subjective economic conditions, frequency of going outside, and eating meals with others; in Model 2, care recipients' satisfaction with care services was added to Model 1.

Results: The mean of SCRQoL scores were 0.58, respectively. In Model 1, the scores were significantly associated with sex, care-level, self-rerated health, subjective economic conditions, frequency of going outside, eating meals with others. In Model 2, the scores were significantly associated with care-level, self-rerated health, subjective economic conditions, frequency of going outside, eating meals with others and care recipients' satisfaction with care services.

Conclusion: SCRQoL scores measured by the Japanese version of ASCOT-SCT4 was strongly associated with subjective evaluation, such as subjective economic conditions, self-rerated health, and satisfaction with care services. The frequency of social participation, such as going outside and eating with others, could contribute to higher SCRQoL scores. Therefore, this study suggests the need to promote social participation among potential clients with care needs.

Fukushima dai-ichi nuclear accident required extensive risk management among society. This risk management was not easy and caused social confusion. Of these, the safety of drinking water is the basis of life and requires a clear explanation of facts. Therefore, Japanese criteria on concentration of radioactive substances in drinking water were discussed with regards to ones in other countries and international ones. The methodology employed in Japan for deriving the concentrations for the countermeasure against the Fukushima nuclear accident were based on international guidelines.

The derived criteria have their own characteristics and specific background so that it is not appropriate to compare numerical values only in each criterion.