Published papers

Hypertension has become a serious problem in Japan, affecting one-third of the population. The Japanese government has set guidelines aimed at improving hypertension (e.g., “The first term of the National Health Promotion Movement in the Twenty-First Century” (Healthy Japan 21 (first term)). However, the improvement goal for hypertension, namely, a reduction in average systolic blood pressure by 4.2 mmHg, has remained unachieved for over a decade. This suggests a limit to the degree that hypertension can be prevented through lifestyle modification alone. Therefore, providing a healthy residential environment that is not affected by behavior changes is needed for health maintenance and promotion. Against this background, the effects of the indoor thermal environment on blood pressure have attracted attention. It has been noted that blood pressure variability, particularly morning blood pressure surge, is affected by the indoor thermal environment. However, studies on these effects are insufficient. The purpose of this study was therefore to clarify how temperature in various rooms and at various times affects morning blood pressure surge, and to quantify effects of room temperature on blood pressure changes before and after getting out of bed. A field survey on ambulatory blood pressure and indoor temperature was conducted in a hilly and mountainous area in Japan in winter month 2012. Ambulatory blood pressure was measured at 30-min intervals from 7 am to 10 pm and at 60-min intervals from 10 pm to 7 am for 7 days, in accordance with the “Guidelines for the clinical use of ambulatory blood pressure monitoring” of the Japanese Circulation Society, the Japanese Society of Hypertension, and the Japanese College of Cardiology. Indoor temperature at 1.1 m above the floor was measured in the living room, bedroom, bathroom, and outdoors at 10-min intervals. Additionally, a questionnaire on personal factors and housing was carried out. Details of the field survey are given in Section 2. Participants in this study were 21 older adults (mean age 68 years (54–74 years)) with average build. As shown in Fig. 5, on the date when bedroom temperature was lowest (lowest day), morning blood pressure surge was larger by 8.1 mmHg than on the date when bedroom temperature was highest (highest day, p<0.05). This tendency was not observed for living room temperature or outdoor temperature. In addition, bedroom temperature at the time of getting out of bed, not mean temperature while sleeping or 2 h before or after getting out of bed, affects morning blood pressure surge (p<0.05) (Fig. 6). Also, as shown from Fig. 10, the blood pressure gap between the lowest day and the highest day is larger after getting out of bed than before. This is likely because residents were covered by a blanket before getting out of bed, but were exposed to the colder environment after removing the blanket and getting out of bed. Older adults at high risk of cardiovascular events should maintain a bedroom temperature within an appropriate range at the time of waking. These findings may have important implications for managing hypertension and preventing cardiovascular events

The effect of CO 2 reduction in Japanese residential sector on various future scenarios for low-carbon society was estimated by the developed forecasting model considering the difference of energy consumption structure in different family types, different geographical area and different house types. Based on the results of forecasting model simulation by 2050, needed policies to achieve the Japanese CO 2 reduction goal (25% reduction at 2020 and 80% reduction at 2050 comparing to CO 2 emission at 1990) was discussed in this study. Results of forecasting simulation showed following 2 aspects. 1. Spread of low carbon technologies (LCT) into residential sector was indispensable to achieve the CO 2 reduction goal in 2050, however, the spread speed of LCT couldn't catch up with the expected speed of CO 2 reduction to reach the goal in 2020. As an additional measure, reduction of CO 2 emission factor for electricity was indispensable. 2. Spread of LCT into existing houses was indispensable to achieve CO 2 reduction goal both in 2020 and 2050, because the CO 2 reduction was not enough to achieve those goals even if the introduction of LCT was obligated to all of new buildings.

This paper describes the results of a literature survey and comparative analysis of unit energy consumption data in the commercial sector. First, we collected 59 documents, including survey reports by administrative agencies, research papers by individual researchers, estimates based on existing surveys, and energy supply statistics. Then, we compared the data and clarified the consistency and variation. To determine the factors causing the variation, we used a dataset on completed buildings, compiled by the Japan Building Mechanical and Electrical Engineers Association.

The Japanese population is ageing, and currently has the world's highest proportion of elderly people. As one consequence, the number of residents in nursing homes is increasing. The Ministry of Health, Labour and Welfare of Japan has identified preventing a need for care as an important aim. The ministry defines “care prevention” in two parts: preventing a care-requiring condition from arising and, when a care-requiring condition already exists, aiming to improve while preventing deterioration. However, mean care level in nursing homes is still increasing, and existing care-prevention strategies are not enough to prevent future increase. A field survey was conducted to clarify the effect of indoor thermal environment on the care-requiring condition of residents in nursing homes. Twenty private residential-nursing homes, located in the Osaka, Kyoto, Nara and Hyogo prefectures of Japan, were included in this study. Room temperature and relative humidity were measured over approximately 4 weeks in private rooms, the dining room and other rooms of each facility at 20-min intervals in winter 2015. Additionally, questionnaire surveys were conducted twice, in winter 2015 and winter 2016. In the questionnaire, care level and date of certification of care needs was investigated for all care certifications in effect after occupancy until the time of the survey. Most facilities had a relatively warm but dry indoor environment. Fifteen facilities were classified into two groups (warm and cold) based on measured room temperature and two groups (moist and dry) based on measured relative humidity. The Kaplan-Meier method was used to analyse the speed of deterioration (i.e., intensification) of required care level. Residents in the dry facility deteriorated with respect to care level more quickly than residents in the moist facility. In contrast, there was no significant difference according to room temperature. Many factors influence care requirements, including not only the indoor thermal environment but also individual attributes, injury and diseases. To assess these influences, multivariate analysis was carried out. Cox proportional hazards regression analysis was used for multivariate analysis to assess the effect of indoor thermal environment on the care-requiring condition of residents in nursing homes. Two questions were evaluated: “Did the care level deteriorate?” and “If so, how long did it take for care level to deteriorate?” The analysis result showed the cold group and the dry group having a higher risk of deterioration of care level. Furthermore, residents in facilities that were both warm and moist had the lowest risk. This result suggests that both temperature and humidity are important for care prevention. The study results are expected to contribute to improvement in indoor thermal environments and to care-prevention among residents of nursing homes.

既報（№12）で得られたホルムアルデヒドの放散、開放型暖房機器等からのSOx、NOxの排出による健康へのダメージ関数を利用し、戸建住宅について、換気回数の変化が人間健康被害と内部・外部費用に与える影響のライフサイクルインパクトを評価した。

国土交通省の支援の下に、筆者らが研究・開発してきた建築物総合環境性能評価システム（CASBEE）の基本概念と新築建物を評価する手法を述べた。

建材等からのホルムアルデヒドの放散、開放型暖房機器等からのＳＯx、ＮＯxの排出による健康被害を定量化するダメージ関数を導出し、これまで扱えなかった室内空気汚染をライフサイクルアセスメントに利用できるようにした。

Demand among large office buildings for the energy-saving benefits of the HVAC (Heating,Ventilating and Air-Conditioning)System are increasing as more and more people become concerned with global environmental issues. However,immoderate measures taken in the interest of energy conservation may encroach on the thermal comfort and productivity level of office workers. Building management should satisfy both indoor thermal comfort and energy conservation while adapting to the many regulatory, social, climate, and other changes that occur during the lifespan of the building. This paper demonstrates how optimal control of the HVAC system, based on data modeling and the multi-objective optimal method,achieves an efficient equilibrium between thermal comfort and energy conservation.

Reduced sleep quality is a serious problem. Previous studies have reported that the thermal environment affects sleep, and that although thermal environmental control via cooling is necessary, this increases energy consumption. Here, we conduct an economic evaluation of the impact of thermal environment control on both sleep quality and energy consumption through experiments conducted in August 2013 and 2014. Reduced sleep efficiency led to decreased work efficiency. The economic impact of improving sleep quality was much greater than that of energy consumption. This study showed importance of the improvement of the sleep quality.

Community-level decentralized and self-reliant energy network is expected to contribute to create a sustainable community as well as its self-vitalization and energy resiliency. But implementation of this system requires consensus among variety of stakeholders and long payback period, which are major hurdles. This study proposes the following concept and methods; (1) PPP business scheme consisting of two types of actors; "community-level energy network infrastructure operating company" and "on-site energy production and service providers" (2) Proper re-allocation of cost and co-benefits among stakeholders by taking advantage of opportunities of adjusting tariffs, taxes, subsidies for the purpose of equalizing each stakeholder’s B/C.

The purpose of this study is to analyze the health determinant factors of housing and regional environment in the suburb of Kitakyushu. A questionnaire survey was carried out among the middle-aged and elderly people in Yatsue district, the city of Kitakyushu, in order to clarify the respective influence of houses and regional environment, including the various sur-rounding environments, on residents' health. As for self-rated health, 80% of the respondents claimed, “I am in good health” or “I am not in bad health”, and there was no great distinction among age groups. The result can be shown that this district is healthy. Health related factors modeling showing the relations among housing, regional environments, and health was proposed, based on structural equation modeling. This model indicated that 23% of residents' health may be dependent on the influences of their houses and regional environments. This model also showed that residents' health had strong cor-relation to questionnaire items such as “indoor thermal environment” of houses, and “community activities”, “neighbor-ship” and “green space” for regional environments. Therefore, it is possible that residents' health may require appropriate maintenance through creation of good house and regional environment.

It is expected that medical and nursing care expenses reached 45 trillion yen in 2010, and such expenses are expected to double to 92 trillion yen by 2025. An effective measure for lowering such expenditures is the prevention of cardiovascular disease, a major cause of which is hypertension. Recently, the effects of the indoor thermal environment on blood pressure have attracted attention. However, these effects have not been studied in relation to personal factors, particularly individual attributes and lifestyle. Therefore, the purpose of this research is to analyze the relation between indoor temperature and blood pressure while taking into account personal factors. Field surveys on home blood pressure, indoor temperature, and personal factors were conducted in winter 2012 and 2013. Controlling for personal factors, systolic blood pressure increased by 4.3 mmHg per 10 °C decrease in indoor air temperature. Also, a 1 °C decrease in indoor air temperature increased 1.1-fold the likelihood of a value above 135 mmHg (baseline for systolic blood pressure at home). Furthermore, the effect of indoor air temperature was stronger in residents with more severe arteriosclerosis.

Population aging is accelerating in many developed countries and there are growing concerns about increasing social security costs. Given this background, as stated in the Japanese Growth Strategy, community that can sustain citizens' lifelong health and active living is required. Therefore, this study aims to develop a healthy community checklist based on citizens’ consciousness and behavior survey to recognize the condition of their community and notice the risk factor of disease. Based on the answer of the respondents, the score for a community was calculated and verified the effectiveness of this tool. As the result, the relationship between overall community score and citizens' health condition was quantified. Furthermore, the result showed a significant relationship between the community environment and the personal health, even in the case of considering personal life style.

The number of patients with heat stroke, sleep disorder and heat shock caused by poor indoor condition increased, becoming a major social issue. As the house is the base of life, the improvement of residential environment that supports resident's health is a pressing issue. This study figured out the effect of residential environment on resident’s health and developed the residential environment assessment tool for health promotion. Then, verified the effectiveness of this tool. People recognize the level of their house and notice the risk factors of disease in their house through the evaluation result with this tool. It will be highly motivating for them to improve the residential environment for health promotion.

The reduced ability to exercise and the increasing prevalence of overweight and obesity in students have recently become serious health concerns. Decreased physical activity in students is cited as a factor in these problems. Governmental agencies have promoted improvement of the regional environment in order to encourage physical activity in students. However, there is insufficient quantitative verification of the regional environmental factors that affect the physical activity of students. Therefore, the purpose of this study was to clarify the relationship between the regional environment and physical activity in students, using a questionnaire survey and actual measurements of physical activity. A questionnaire survey was conducted for more than 300 teachers across 13 elementary schools to evaluate the satisfaction with the natural environment, the public security, the facilities for communication and the public facilities of each school district. Also, a measurement survey was conducted in the same public schools in Kawasaki city and data were obtained from 702 students aged 10-11 years old across 13 school districts. During a week of September to November 2014, the number of walking steps of each student was measured by a pedometer, HJ326F and HJA-350IT (OMRON). 1) Impact of the regional environment on physical activity Using the results of a questionnaire survey and actual measurements of physical activity, we conducted the multi-level model analysis in order to clarify the impact of the regional environment on physical activity of students in taking account of individual attributes. As a result, for school regions where the satisfaction with the natural environment and the public security were high, the number of walking steps on weekdays exceeded those where the satisfaction was lower. According to the multi-level model analysis, the regional average number of steps increased by about 300 for every 1pt increase in the satisfaction score of the natural environment and the public security. 2) Relation between satisfaction with neighborhood environments and land use Although we examined the relationship between the satisfaction with neighborhood environment and physical activity in students, a concrete factor which increases such satisfaction with regional environment was unclear. Therefore, we carried out a correlation analysis between the satisfaction score of neighborhood environments and the land use and the zoning of the regions. The satisfaction score of the natural environment of a region was correlated with the proportion of a forested region. We also examined the negative correlation between the satisfaction with natural environment and the proportion of a dense low storied building area. In conclusion, the result of this study confirmed a relationship between regional environment and physical activity in students and showed the significance value of the natural environment, the public security and the facilities for communication to encourage physical activity in students.

In recent years in Japan, the promotion of physical activity has been emphasized as a means of preventing lifestyle diseases. A large body of research has been conducted on environmental factors that influence physical activity, but much of that work deals with only the community environment, leaving the relationship between housing environment and physical activity unclear. Against this background, we aimed to clarify the effects of housing environment on physical activity. We hypothesized that inhabitants would be hesitant to perform physical activities in cold houses during winter and that the amount of physical activity would therefore decrease. Furthermore, we hypothesized that due to the correlation between indoor thermal environment and insulation efficiency, high insulation efficiency would be effective for promoting physical activity. To test this hypothesis, we conducted a questionnaire survey and actual measurements in Niihama City in Ehime Prefecture, Japan, to examine the relationship between indoor thermal environment, insulation efficiency, and physical activity. As shown in Table 1, the questionnaire evaluated the housing environment, degree of physical activity, lifestyle, and personal attributes. To assess the items in Table 2, which pertained to physical activity and indoor temperature, we conducted actual measurements during fall and winter. Physical activity was measured using a physical activity monitor that participates wore daily for approximately 2 weeks. Indoor temperature and humidity were measured with thermo-hygrometers installed at a height of about 1 meter in the living room, bedroom, lavatory, and corridor of each participant’s house, and measurements were recorded every 10 min for approximately 1 month. Statistical analysis of the survey results revealed that people who perform less physical activity in winter than in fall tend to live in colder houses (Fig. 3). We then performed multiple regression analysis (stepwise selection) to examine the relation between indoor thermal environment and physical activity (Table 5), and found that after adjusting for biological factors, socioeconomic status, lifestyle , and outdoor temperature, greater physical activity was associated with higher minimum temperature of the lavatory and corridor (Table 6-9). Because the lavatory and corridor are considered representative of non-living-room spaces, where air heating is seldom used, these results indicated that warmer non-living room spaces are effective for promotion of physical activity. Lastly, high insulation efficiency can be considered effective for promotion of physical activity, as shown by the correlation between indoor thermal environment and insulation efficiency.

既出論文の続報であり、各種の対策によるLCCO2排出量など削減効果を詳細に検討した。

In recent years, with improvements in living standards, energy consumption and CO2 emissions of Chinese residential sector have both increased considerably. However, we do not have a clear vision of future growth in energy consumption and lack tools for evaluating the impact of energy saving measures. This paper discusses the sustainability of Chinese residential buildings from the following 3 aspects: 1. Analyzing the future growth of energy consumption in Chinese residential buildings. 2. Evaluating the reduction potential of CO2 emissions through the implements of various energy saving measures. 3. Calculating the marginal abatement cost of proposed countermeasures and evaluating them from an economic perspective.　 As results, we found that efficiency policies could bring about 70% CO2 emissions reduction in maximum. Hence, most of the efficiency policies have positive effects on saving energy bills, thus the marginal abatement costs are able to be managed in a minus level.