Published papers

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This study investigated the relationship between perceived indoor temperature in winter and frailty among community-dwelling older people. This cross-sectional study included 342 people 65 years and older in Japan. Participants answered questions about demographics, frailty, housing, and perceived indoor temperature in winter. Participants were grouped based on perceived indoor temperature (Cold or Warm) and economic satisfaction (Unsatisfied or Satisfied). Differences in the frailty index between perceived indoor temperature groups and economic satisfaction groups were tested by using ANCOVA and MANCOVA. An interaction effect showed that people in the Cold Group and unsatisfied with their economic status had significantly higher frailty index scores (F(1, 336) = 5.95, p = 0.015). Furthermore, the frailty index subscale of fall risk was the specific indicator of frailty that accounted for this significant relationship. While previous research has shown the risks related to cold indoor temperature in homes, interestingly among those who reported cold homes, only those who were not satisfied with their economic situation reported being at increased risk for frailty. This highlights the potential importance of preventing fuel poverty to prevent frailty.

Objective Bath-related sudden cardiac arrests occur frequently in Japan. Although previous studies have reported that most fatal events occurr in winter, the reason why such events exhibit a seasonal variation has not been elucidated. In this study, we hypothesized that the occurrence of bath-related deaths was correlated with a low air temperature. Methods This prospective cross-sectional observational study was conducted in the Tokyo Metropolitan area between October 2012 and March 2013. Data were collected for all cases involving the activation of the emergency medical system because of an accident or acute illness related to bathing that occurred in Tokyo during the study period. In particular, elderly (≥65 years) cardiac arrest victims who had been found in a bathtub filled with water were enrolled. The relationship between the daily number of cardiac arrest events and the lowest daily air temperature in Tokyo was studied using a nonlinear regression model. Results A total of 3,624 bath-related events were registered in this study. Among these events, 1,081 deaths of elderly individuals who had been found in a bathtub filled with water were recorded. A close correlation was observed between the daily number of events and the lowest daily air temperature. This correlation was described by the following equation: y=8.38e-0.07x, where y was the daily number of cardiac arrests and x was the lowest daily air temperature. Conclusion A low air temperature was closely correlated with the occurrence of bath-related cardiac arrest.

© 2019 The Japanese Society of Internal Medicine. Objective Bath-related sudden cardiac arrests frequently occur in Japan. This study aimed to describe the actual incidence and characteristics of bath-related accidents, including non-fatal events, and to establish the etiology of bath-related sudden cardiac arrest. Methods This prospective cross-sectional observational study was conducted in Tokyo Metropolis and Saga and Yamagata Prefectures between October 2012 and March 2013. Emergency personnel enrolled events in this study when they recognized that activation of the emergency medical system was related to bathing. Surveillance cards were delivered and collected from the emergency personnel and attending physicians. Results In total, 4,593 events were enrolled (1,528 cardiac arrests, 935 survivors in need of help, 1,553 patients with acute illnesses, and 577 patients with injuries) in this study. In the group of survivors in need of help and with acute illness, consciousness disturbance and lethargy without any organic disease were recognized as the main symptoms. Acute coronary syndrome and stroke were infrequently diagnosed. Of the survivors, 30% had a body temperature above 38°C. Their consciousness level significantly correlated with their body temperature. Emergency personnel reported that 79% of sudden cardiac arrests were from victims whose faces were submerged in the tub water, while 18% of survivors had their faces submerged in the tub water. Conclusion This study revealed that accidents, including non-lethal events, frequently occur. The key symptoms were consciousness disturbance and lethargy characterized as a functional disorder and accompanied by an elevated body temperature. Those findings suggest that heat illness during hot water immersion causes drowning.

© 2020 Elsevier Inc. OBJECTIVE: To assess the relationship between overactive bladder (OAB) and indoor temperatures in the living room and bedroom. METHODS: Questionnaire data and indoor temperature measurements were obtained from a baseline survey collected during the winter months from November 2014 to March 2019. We performed multiple logistic regression to assess the relationships between OAB and indoor temperatures in the living room and bedroom. RESULTS: The prevalence of overactive bladder was 16.4% among 4782 participants living in 2453 dwellings. The odds of having OAB were higher for participants whose average living room temperature at bedtime was lower than 12°C than for those whose average bedtime living room temperature was at least 18°C (adjusted odds ratio = 1.44, 95% confidence interval: 1.03-2.00). No association was observed between bedroom temperature and OAB. CONCLUSION: These results suggest that thermal comfort in the living room—but not in the bedroom—may improve OAB symptoms. Additionally, using sufficient bedding may prevent cold bedrooms from having a negative impact in terms of OAB. Future studies should focus on housing interventions and education regarding lifestyle modification in patients with OAB.

OBJECTIVE: The WHO's Housing and health guidelines (2018) listed 'low indoor temperatures and insulation' as one of five priority areas, and indicated insulation retrofitting to help mitigate the effect of low indoor temperatures on health. However, there is still not enough evidence for the effect of insulation retrofitting based on an objective index. METHODS: We conducted a nonrandomized controlled trial comparing home blood pressure (HBP) between insulation retrofitting (942 households and 1578 participants) and noninsulation retrofitting groups (67 households and 107 participants). HBP and indoor temperature were measured for 2 weeks before and after the intervention in winter. To examine the influence of insulation retrofitting on HBP, we used multiple linear regression analysis. RESULTS: The analyses showed that indoor temperature in the morning rose by 1.4°C after insulation retrofitting, despite a slight decrease in outdoor temperature by 0.2°C. Insulation retrofitting significantly reduced morning home SBP (HSBP) by 3.1 mmHg [95% confidence interval (95% CI): 1.5-4.6], morning home DBP (HDBP) by 2.1 mmHg (95% CI: 1.1-3.2), evening HSBP by 1.8 mmHg (95% CI: 0.2-3.4) and evening HDBP by 1.5 mmHg (95% CI: 0.4-2.6). In addition, there was a dose-response relationship between indoor temperature and HBP, indicating the effectiveness of a significant improvement in the indoor thermal environment. Furthermore, there was heterogeneity in the effect of insulation retrofitting on morning HSBP in hypertensive patients compared with normotensive occupants (-7.7 versus -2.2 mmHg, P for interaction = 0.043). CONCLUSION: Insulation retrofitting significantly reduced HBP and was more beneficial for reducing the morning HSBP of hypertensive patients.

Previous studies have revealed the relationships between specific residential environmental factors and residents' health status. However, no study has considered the comprehensive health risk due to the overall residential environment. Therefore, a large-scale nationwide questionnaire survey was conducted using the CASBEE Health Checklist to examine the residential environment of detached houses and residents' health status. This analysis indicated that the overall residential environment is likely an important determinant of health and was associated with disease prevalence among residents.

Fever and hyperthermia are the main symptoms of coronavirus disease (COVID-19) and heatstroke, and it is difficult to distinguish them. There is a need to discuss safe prevention and medical treatment for heatstroke. In view of the above issues, the Japanese Association for Acute Medicine "Committee on heatstroke and hypothermia" established a "Working group on heatstroke medical care given the COVID-19 epidemic" jointly with the Japanese Society for Emergency Medicine that focuses on emergency medical personnel, including paramedics and nurses, the Japanese Association for Infectious Diseases, an academic society of infectious disease, and the Japanese Respiratory Society, an academic organization on respiratory diseases. The precautions for prevention of heatstroke this summer during the coronavirus epidemic was summarized in "Proposals on heatstroke prevention based on the COVID-19 epidemic" as follows and was issued on 1 June, 2020. Based on the above, we have determined that guidance in clinical practice is necessary not only from the viewpoint of heatstroke prevention, but also medical treatment. As such, we have created this guidance in the form of supplementary recommendations.

© 2019 by the authors. Governments at different levels need to appreciate the environmental impacts of socioeconomic activities within their boundaries. They also need to decide relevant environmental policies after carefully examining future pathways based on the relationship between the environment and the economy. This study focuses on Japanese basic administrative divisions (i.e., municipalities) and attempts to quantify the annual environmental efficiency of processes and socioeconomic activities within each of these divisions using life-cycle impact assessment (LCIA) concepts. A key element of the LCIA is the integration of different environmental loads across various impact categories, such as global warming, air pollution, and land use, and their representation through a simple indicator. First, we conduct annual environmental impact assessments for all Japanese municipalities based on reliable, verifiable, and comparable statistical information. Next, we estimate the environmental efficiency of socioeconomic activities within each division by dividing the gross regional product (GRP) with the environmental damage amounts calculated through LIME2, an LCIA-based tool tailored for Japan. Assessment results for each municipality are visualized on maps of Japan in order to highlight the spatial distribution of the values for each indicator. The findings of this study can aid local, regional, and national governments in Japan to inform environmental policy design and decision-making at different spatial levels.

© 2020 The Authors A possibility of developing an environmental-friendly photovoltaic/thermal (PV/T) solar panel, which can shut high temperature radiation within a panel box, was experimentally confirmed. The panel has a decompression-boiling heat collector, which can absorb heat from the PV module and can keep the air and the cover glass inside the panel box at lower temperature by using lower boiling temperature of working fluid under vacuum condition. The panel also has an emboss-processed cover glass, which can totally reflect the high temperature heat radiation from the PV module within the panel box. The experimental results using a single PV/T system showed that it could keep the heat radiation temperature from the PV/T solar panel surface around 45 °C even in summer; it provided the hot water at least 60 °C by controlling the flow-rate; and it produced 71.3% of solar energy in total as electricity and 40 °C heat, in summer, Yokohama, Japan. Highly efficient utilization of solar energy with small environmental heat-load would be possible by using the proposed PV/T system.

Mortality due to cardiovascular disease rises sharply in winter. Known as excess winter mortality, this phenomenon is partially explained by cold exposure-induced high blood pressure. Home blood pressure, especially in the morning, is closely associated with cardiovascular disease risk. We conducted the first large nationwide survey on home blood pressure and indoor temperature in 3775 participants (2095 households) who intended to conduct insulation retrofitting and were recruited by construction companies. Home blood pressure was measured twice in the morning and evening for 2 weeks. The relationship between home blood pressure and indoor temperature in winter was analyzed using a multilevel model with 3 levels: repeatedly measured day-level variables (eg, indoor ambient temperature and quality of sleep), nested within individual-level (eg, age and sex), and nested within household level. Cross-sectional analyses involving about 2900 participants (1840 households) showed that systolic blood pressure in the morning had significantly higher sensitivity to changes in indoor temperature (8.2 mm Hg increase/10°C decrease) than that in the evening (6.5 mm Hg increase/10°C decrease) in participants aged 57 years (mean age in this survey). We also found a nonlinear relationship between morning systolic blood pressure and indoor temperature, suggesting that the effect of indoor temperature on blood pressure varied depending on room temperature range. Interaction terms between age/women and indoor temperature were significant, indicating that systolic blood pressure in older residents and women was vulnerable to indoor temperature change. We expect that these results will be useful in determining optimum home temperature recommendations for men and women of each age group. Clinical Trial Registration- URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000030601.

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Fungal community analyses in homes have been attracting attention because fungi are now generally considered to be allergens. Currently, these analyses are generally conducted using the culture method, although fungal communities in households often contain species that are difficult to culture. In contrast, next-generation sequencing (NGS) represents a comprehensive, labor-and time-saving approach that can facilitate species identification. However, the reliability of the NGS method has not been compared to that of the culture method. In this study, in an attempt to demonstrate the reliability of this application, we used the NGS method to target the internal transcribed spacer 1 (ITS1) in the fungal genome, conducted fungal community analyses for 18 house-dust samples and analyzed fungal community structures. The NGS method positively correlated with the culture method regarding the relative abundance of Aspergillus, Penicillium, Cladosporium and yeasts, which represent the major fungal components found in houses. Furthermore, several genera, such as Malassezia, could be sensitively detected. Our results imply that the reliability of the NGS method is comparable to that of the culture method and indicates that easily available databases may require modifications, including the removal of registrations that have not been sufficiently classified at the genus level.

© 2019 Tsuboi et al. Background: Unlike traditional East Asian medicine, the necessity of health care services for cold extremities is yet to be acknowledged in Western medicine. In this study, we aimed to conduct an epidemiological evaluation of this unremarkable symptom among women in Japan. Materials and methods: A cross-sectional study was conducted from February 2016 to April 2017, and data of 238 women throughout Japan were analyzed. Questionnaires were used to examine participants’ demographics, health-related behaviors, health status, and frequency of subjective symptoms over the past 1 year. The association between cold extremities and other subjective symptoms was examined by the multiple logistic regression analysis. Results: The prevalences of mild and severe cold extremities were 49.6% and 35.3%, respectively. Temperature and utilization of health care services were not significantly different by the severity of cold extremities. The accompanying symptoms that were significantly associated with the cold extremities were shoulder stiffness, fatigue, low back pain, headache, nasal congestion, itching, injury, and difficulty hearing. After multiple logistic regression analysis, low back pain (OR: 4.91) and difficulty hearing (OR: 4.84) kept the significance. Factors related to cold extremities including mental quality of life, sleep quality, and habitual drinking were significantly associated with other accompanying symptoms. Conclusion: Women with cold extremities have various accompanying symptoms and health-risk behaviors. Symptomatic treatment for cold extremities may not be sufficient, and comprehensive care would be required.

The purpose of this paper is to show the effectiveness of porous residential buildings in hot and humid regions in the light of cooling load and CO2 emission reductions. Thermal and Airflow Network analysis and LCA analysis are used for these simulations. Two scales of voids, namely building-scale voids and component-scale voids are considered. In the previous paper (Hirano et at. Building and Environment, forthcoming), it was revealed that building-scale voids are substantially effective in terms of reducing the cooling load. This paper firstly focuses on the cooling load reduction effects of component-scale voids, then moves on to the CO2 emission reduction effects of both component- and building-scale voids. Additionally, other environmentally friendly techniques are examined in order to assess the feasibility of the Architectural Institute of Japan (AIJ) charter, which sets the target that new buildings should extend their service life up to 100 years as well as reduce Life-Cycle CO2 (LCCO2) emission by 30%. (c) 2005 Elsevier Ltd. All rights reserved.

This study targets environmental load reduction in hot and humid regions. It reveals the effects that porous residential buildings have on the natural ventilation performance and, consequently, the cooling load reduction. Two residential building models, namely a model with a void ratio of 0% and a model with a void ratio of 50%, are evaluated using computational fluid dynamics (CFD) analysis and thermal and airflow network analysis. The analysis on components of the heat load indicates that improvements in the natural ventilation performance would significantly reduce the cooling load. (c) 2005 Elsevier Ltd. All rights reserved.

Under the Paris Agreement, Japan promises reducing 26 % from greenhouse gas emissions in 2013 by 2030. We have proposed a concept of Cluster Energy Management System, CEMS, which can design a highly saving-energy network based on demand simulation of communities consisting various different residents. As an example of CEMS designing a good thermal and electricity demand-balance among a network of residential houses, commercial and nursing facilities is introduced. The network can use almost whole exhaust heat from distributed power plant such as fuel cell with solar power and thermal utilization. We can simulated saving about 40 % in prime-energy consumption and about 45 % reduction of CO2 emission by designing an example case of the CEMS, which combines fuel cells and electric vehicles in a community, where 200 families including elderly people are living. We concluded that it would be possible to reduce primary energy consumption and CO2 emission by nearly a half amount or more by introducing the CEMS.

Under the Paris Agreement, Japan promises reducing 26 % from greenhouse gas emissions in 2013 by 2030. We have proposed a concept of Cluster Energy Management System, CEMS, which can design a highly saving-energy network based on demand simulation of communities consisting various different residents. As an example of CEMS designing a good thermal and electricity demand-balance among a network of residential houses, commercial and nursing facilities is introduced. The network can use almost whole exhaust heat from distributed power plant such as fuel cell with solar power and thermal utilization. We can simulated saving about 40 % in prime-energy consumption and about 45 % reduction of CO2 emission by designing an example case of the CEMS, which combines fuel cells and electric vehicles in a community, where 200 families including elderly people are living. We concluded that it would be possible to reduce primary energy consumption and CO2 emission by nearly a half amount or more by introducing the CEMS.

Heat island phenomenon has significantly become worse in Tokyo metropolitan area in recent years. This leads to a drastic increase of patients with sleep disorder. The sleeping environments are much affected by the building performance and the ways occupants live in their houses. Interaction of human physiology and the thermal environment throughout the sleeping time makes it difficult to evaluate the sleeping environments. In this paper, we analyzed a sleeping environment by means of coupled simulations of the heat and airflow network model and Computational Fluid Dynamics (CFD) incorporated with thermoregulation model. Results showed that the use of air conditioner being operated to adapt to human metabolism can be effective to lower the core temperature and lead to a good sleep.

CASBEE (Comprehensive Assessment System for Building Environmental Efficiency) is an environmental labeling method for buildings, based on assessment of the environmental performance of buildings. In CASBEE, BEE (Building Environmental Efficiency) was developed as a new indicator for assessment following the concept of eco-efficiency. With the increasing BEE value, the total environmental performance of buildings is labeled from the highest performance. The framework of basic and extended CASBEE tools as a structured assessment system is called the "CASBEE family." CASBEE consists of a set of four basic assessment tools; namely, "CASBEE for Pre-design" (CASBEE-PD), "CASBEE for New Construction" (CASBEE-NC), "CASBEE for Existing Building" (CASBEE-EB), and "CASBEE for Renovation" (CASBEE-RN). These correspond to the individual stages of the building's lifecycle. There are also needs for detailed assessment targeting specific environmental aspects. "CASBEE-HI," as an extended tool, assesses efforts made in buildings to alleviate the heat island effect. A new tool called "CASBEE for Urban Development" (CASBEE-UD) is developed for assessment of a group of buildings. Some local authorities introduced CASBEE into their building administration as assessment methods for their sustainable building reporting systems. This requires building owners to submit a planning document assessing the environmental performance of their buildings to the authorities. In April 2004, the city of Nagoya introduced "CASBEE Nagoya." Introduction of CASBEE followed in the city of Osaka, Yokohama, Kyoto, and other municipals. These local systems require some modification in CASBEE to reflect their local characteristics, such as climate and prioritized policies. Copyright © 2008 by ASTM International.

This paper outlines the energy consumption and greenhouse gas emission trends in the residential and commercial sectors in Japan. The results showed that the increase in residential energy consumption in Japan is mainly caused by the widespread use of heating equipment, hot water supply apparatus, and other household electrical appliances. On the other hand, it was indicated that the increase in commercial energy use is mainly due to the increase of the floor area of buildings, particularly hotels, hospitals, and department stores. The paper also describes political measures to promote energy conservation, including the building energy conservation standard, Comprehensive Assessment System for Building Environmental Efficiency, top runner programs, financial incentives, and the dissemination of the Cool Biz concept. Finally, the projections of CO2 emissions until 2050 are presented. © Springer Science+Business Media B.V. 2009.