In Japan, major and minor bimodal seasonal patterns of varicella have been observed. To investigate the underlying mechanisms of seasonality, we evaluated the effects of the school term and temperature on the incidence of varicella in Japan. We analyzed epidemiological, demographic and climate datasets of seven prefectures in Japan. We fitted a generalized linear model to the number of varicella notifications from 2000 to 2009 and quantified the transmission rates as well as the force of infection, by prefecture. To evaluate the effect of annual variation in temperature on the rate of transmission, we assumed a threshold temperature value. In northern Japan, which has large annual temperature variations, a bimodal pattern in the epidemic curve was observed, reflecting the large deviation in average weekly temperature from the threshold value. This bimodal pattern was diminished with southward prefectures, gradually shifting to a unimodal pattern in the epidemic curve, with little temperature deviation from the threshold. The transmission rate and force of infection, considering the school term and temperature deviation from the threshold, exhibited similar seasonal patterns, with a bimodal pattern in the north and a unimodal pattern in the south. Our findings suggest the existence of preferable temperatures for varicella transmission and an interactive effect of the school term and temperature. Investigating the potential impact of temperature elevation that could reshape the epidemic pattern of varicella to become unimodal, even in the northern part of Japan, is required.
BACKGROUND: The impact of climate change on mental health largely remains to be evaluated. Although growing evidence has reported a short-term association between suicide and temperature, future projections of temperature-attributable suicide have not been thoroughly examined. OBJECTIVES: We aimed to project the excess temperature-related suicide mortality in Japan under three climate change scenarios until the 2090s. METHODS: Daily time series of mean temperature and the number of suicide deaths in 1973-2015 were collected for 47 prefectures in Japan. A two-stage time-stratified case-crossover analysis was used to estimate the temperature-suicide association. We obtained the modeled daily temperature series using five general circulation models under three climate change scenarios from the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) Shared Socioeconomic Pathways scenarios (SSPs): SSP1-2.6, SSP2-4.5, and SSP5-8.5. We projected the excess temperature-related suicide mortality until 2099 for each scenario and evaluated the net relative changes compared with the 2010s. RESULTS: During 1973-2015, there was a total of 1,049,592 suicides in Japan. Net increases in temperature-related excess suicide mortality were estimated under all scenarios. The net change in 2090-2099 compared with 2010-2019 was 1.3% [95% empirical confidence interval (eCI): 0.6, 2.4] for the intermediate-emission scenario (SSP2-4.5), 0.6% (95% eCI: 0.1, 1.6) for a low-emission scenario (SSP1-2.6), and 2.4% (95% eCI: 0.7, 3.9) for the extreme scenario (SSP5-8.5). The increases were greater the more extreme the scenarios were, with the highest increase under the most extreme scenario (SSP5-8.5). DISCUSSION: This study indicates that Japan may experience a net increase in excess temperature-related suicide mortality, especially under the intermediate and extreme scenarios. The findings underscore the importance of mitigation policies. Further investigations of the future impacts of climate change on mental health including suicide are warranted. https://doi.org/10.1289/EHP11246.
One of the negative consequences of increased air temperatures due to global warming is the associated increase in heat-related mortality and morbidity. Studies that focused on future predictions of heat-related morbidity do not consider the effect of long-term heat adaptation measures, nor do they use evidence-based methods. Therefore, this study aimed to predict the future heatstroke cases for all 47 prefectures of Japan, by considering long-term heat adaptation by translating current geographical differences in heat adaptation to future temporal heat adaptation. Predictions were conducted for age groups of 7-17, 18-64, and ≥65 years. The prediction period was set to a base period (1981-2000), mid-21st century (2031-2050), and the end of the 21st century (2081-2100). We found that the average heatstroke incidence (number of patients with heatstroke transported by ambulance per population) in Japan under five representative climate models and three greenhouse gas (GHG) emissions scenarios increased by 2.92- for 7-17 years, 3.66- for 18-64 years, and 3.26-fold for ≥65 years at the end of the 21st century without heat adaptation. The corresponding numbers were 1.57 for 7-17 years, 1.77 for 18-64 years, and 1.69 for ≥65 years with heat adaptation. Furthermore, the average number of patients with heatstroke transported by ambulance (NPHTA) under all climate models and GHG emissions scenarios increased by 1.02- for 7-17 years, 1.76- for 18-64 years, and 5.50-fold for ≥65 years at the end of 21st century without heat adaptation, where demographic changes were considered. The corresponding numbers were 0.55 for 7-17 years, 0.82 for 18-64 years, and 2.74 for ≥65 years with heat adaptation. The heatstroke incidence, as well as the NPHTA, substantially decreased when heat adaptation was considered. Our method could be applicable to other regions across the globe.
INTRODUCTION: Heatstroke mortality is highest among older adults aged 65 years and older, and the risk is even doubled among those aged 75 years and older. The incidence of heatstroke is expected to increase in the future with elevated temperatures owing to climate change. In the context of a super-aged society, we examined possible adaptation measures in Japan that could prevent heatstroke among older people using an epidemiological survey combined with mathematical modeling. METHODS: To identify possible interventions, we conducted a cross-sectional survey, collecting information on heatstroke episodes from 2018 to 2019 among people aged 75 years and older. Responses were analyzed from 576 participants, and propensity score matching was used to adjust for measurable confounders and used to estimate the effect sizes associated with variables that constitute possible interventions. Subsequently, a weather-driven statistical model was used to predict heatstroke-related ambulance transports. We projected the incidence of heatstroke-related transports until the year 2100, with and without adaptation measures. RESULTS: The risk factor with the greatest odds ratio (OR) of heatstroke among older adults was living alone (OR 2.5, 95% confidence interval: 1.2-5.4). Other possible risk factors included an inability to drink water independently and the absence of air conditioning. Using three climate change scenarios, a more than 30% increase in the incidence of heatstroke-related ambulance transports was anticipated for representative concentration pathways (RCP) 4.5 and 8.5, as compared with a carbon-neutral scenario. Given 30% reduction in single living, a 15% reduction in the incidence of heatstroke is expected. Given 70% improvement in all three risk factors, a 40% reduction in the incidence can be expected. CONCLUSION: Possible adaptation measures include providing support for older adults living alone, for those who have an inability to drink water and for those without air conditioning. To be comparable to carbon neutrality, future climate change under RCP 2.6 requires achieving a 30% relative reduction in all three identified risks at least from 2060; under RCP 4.5, a 70% reduction from 2050 at the latest is needed. In the case of RCP 8.5, the goal of heatstroke-related transports approaching RCP 1.9 cannot be achieved.
This study analyzed the association between heatstroke incidence and daily maximum wet bulb globe temperature (WBGT) for all 47 prefectures in Japan by age group and severity using time-series analysis, controlling for confounders, such as seasonality and long-term trends. With the obtained association, the relative risk between the reference WBGT (defined as the value at which heatstroke starts to increase) and the daily maximum WBGT at 30 °C (RR(wbgt30)) of each prefecture were calculated. For the heatstroke data, the daily number of heatstroke patients transported by ambulance at the prefecture level, provided by the Fire and Disaster Management Agency, was utilized. The analysis was conducted for age groups of 7-17 y, 18-64 y, and ≥65 y, and for severity of Deceased, Severe, Moderate (combined as DSM), and Mild. The analysis period was set from May 1 to September 30, 2015-2019. Finally, the correlation between RR(wbgt30) and the average daily maximum WBGT during the analysis period (aveWBGTms) of each prefecture was analyzed to examine the regionality of heatstroke incidence. The result showed that RR(wbgt30) is negatively correlated with aveWBGTms for the age group 18-64 y and ≥65 y (except for the age group 7-17 y) and for severity. The natural logarithm of the RR(wbgt30) of all 47 prefectures ranged from 2.0 to 8.2 for the age group 7-17 y, 1.1 to 4.0 for the age group 18-64 y, 1.8 to 6.0 for the age group ≥65 y, and 1.0 to 3.6 for DSM, and 0.9 to 4.0 for Mild. This regionality can be attributed to the effects of heat adaptation, where people in hotter regions are accustomed to implementing measures against hot environments and are more heat acclimatized than people in cooler regions.
The degradation of air quality, an environmental consequence of anthropogenic activities, poses a challenge to human health. However, the corresponding control measures incur additional costs. This study presents an analysis of the health and socioeconomic benefits of air quality control measures and climate change mitigation. Multidisciplinary modelling was used for PM2.5 and ozone distribution to analyze the co-benefits of end-of-pipe measures and electrification as well as their period-specific impacts on human health and the economy. The results indicated that the long-term impacts of end-of-pipe technologies and electrification in Japan’s residential, building, and transportation sectors could reduce premature deaths, caused by PM2.5 and ozone pollution, by 65,500 annually from 2010 to 2050. These technologies could save a per capita work hour loss of 3.64 h and avoid an economic loss of 5.43 billion USD by 2050. This study predicted climate actions would enable western Japan to benefit from PM2.5 control measures, whereas the entire country would benefit from ozone pollution reduction.
BACKGROUND: Air conditioning (AC) presents a viable means of tackling the ill-effects of heat on human health. However, AC releases additional anthropogenic heat outdoors, and this could be detrimental to human health, especially in urban communities. This study determined the excess heat-related mortality attributable to anthropogenic heat from AC use under various projected global warming scenarios in seven Japanese cities. The overall protection from AC use was also measured. METHODS: Daily average 2-meter temperatures in the hottest month of August from 2000 to 2010 were modeled using the Weather Research and Forecasting (WRF) model with BEP+BEM (building effect parameterization and building energy model). Risk functions for heat-mortality associations were generated with and without AC use from a two-stage time series analysis. We coupled simulated August temperatures and heat-mortality risk functions to estimate averted deaths and unavoidable deaths from AC use. RESULTS: Anthropogenic heat from AC use slightly augmented the daily urban temperatures by 0.046 °C in Augusts of 2000-2010 and up to 0.181 °C in a future with 3 °C urban warming. This temperature rise was attributable to 3.1-3.5 % of heat-related deaths in Augusts of 2000-2010 under various urban warming scenarios. About 36-47 % of heat-related deaths could be averted by air conditioning use under various urban warming scenarios. DISCUSSION: AC has a valuable protective effect from heat despite some unavoidable mortality from anthropogenic heat release. Overall, the use of AC as a major adaptive strategy requires careful consideration.
The health effects of heat are well documented; however, limited information is available regarding the health risks of hot nights. Hot nights have become more common, increasing at a faster rate than hot days, making it urgent to understand the characteristics of the hot night risk. OBJECTIVES: We estimated the effects of hot nights on the cause- and location-specific mortality in a nationwide assessment over 43 y (1973-2015) using a unified analytical framework in the 47 prefectures of Japan. METHODS: Hot nights were defined as days with a) minimum temperature ≥ 25°C (HN25) and b) minimum temperature ≥ 95th percentile (HN95th) for the prefecture. We conducted a time-series analysis using a two-stage approach during the hot night occurrence season (April-November). For each prefecture, we estimated associations between hot nights and mortality controlling for potential confounders including daily mean temperature. We then used a random-effects meta-analytic model to estimate the pooled cumulative association. RESULTS: Overall, 24,721,226 deaths were included in this study. Nationally, all-cause mortality increased by 9%-10% [HN25 relative risk (RR) = 1.09, 95% confidence interval (CI): 1.08, 1.10; HN95th RR = 1.10, 95% CI: 1.09, 1.11] during hot nights in comparison with nonhot nights. All 11 cause-specific mortalities were strongly associated with hot nights, and the corresponding associations appeared to be acute and lasted a few weeks, depending on the cause of death. The strength of the association between hot nights and mortality varied among prefectures. We found a higher mortality risk from hot nights in early summer in comparison with the late summer in all regions. CONCLUSIONS: Our findings support the evidence of mortality impacts from hot nights in excess of that explicable by daily mean temperature and have implications useful for establishing public health policy and research efforts estimating the health effects of climate change. https://doi.org/10.1289/EHP11444.
Understanding the location of risk to natural hazards, namely the areas of high exposure and vulnerability is a major priority that was identified by the Sendai framework for Disaster Reduction 2015-2030 in order to reach substantial reduction of disaster risk. It is also a necessary decision-making tool for disaster mitigation policy-makers in Japan and around the world. This paper successfully develops a simple methodology using only open data to build the first large-scale (whole country), fine resolution (sub-municipal level) social vulnerability analysis in the context of five different types of natural hazards (earthquake, tsunami, storm surge, flooding and landslide). The result is then compared to an indicator of exposure of population to these hazards in Japan in order to propose a representation of disaster risk. Results show that vulnerability in Japan is highly heterogeneous with urban/rural and north/south fractures. Combining the social vulnerability index with exposure analysis, results show a wide variety of spatial patterns of risk areas in Japan.
Climate-sensitive diseases developing from heat or cold stress threaten human health. Therefore, the future health risk induced by climate change and the aging of society need to be assessed. We developed a prediction model for mortality due to cardiovascular diseases such as myocardial infarction and cerebral infarction, which are weather or climate sensitive, using machine learning (ML) techniques. We evaluated the daily mortality of ischaemic heart disease (IHD) and cerebrovascular disease (CEV) in Tokyo and Osaka City, Japan, during summer. The significance of delayed effects of daily maximum temperature and other weather elements on mortality was previously demonstrated using a distributed lag nonlinear model. We conducted ML by a LightGBM algorithm that included specified lag days, with several temperature- and air pressure-related elements, to assess the respective mortality risks for IHD and CEV, based on training and test data for summer 2010-2019. These models were used to evaluate the effect of climate change on the risk for IHD mortality in Tokyo by applying transfer learning (TL). ML with TL predicted that the daily IHD mortality risk in Tokyo would averagely increase by 29% and 35% at the 95th and 99th percentiles, respectively, using a high-level warming-climate scenario in 2045-2055, compared to the risk simulated using ML in 2009-2019.
BACKGROUND: Level of care-need (LOC) is an indicator of elderly person’s disability level and is officially used to determine the care services provided in Japan’s long-term care insurance (LTCI) system. The 2018 Japan Floods, which struck western Japan in July 2018, were the country’s second largest water disaster. This study determined the extent to which the disaster affected the LOC of victims and compared it with that of non-victims. METHODS: This is a retrospective cohort study, based on the Japanese long-term care insurance claims from two months before (May 2018) to five months after the disaster (December 2018) in Hiroshima, Okayama, and Ehime prefectures, which were the most severely damaged areas in the country. A code indicating victim status, certified by a residential municipality, was used to distinguish between victims and non-victims. Those aged 64 years or younger, those who had the most severe LOC before the disaster, and those whose LOC increased even before the disaster were excluded. The primary endpoint was the augmentation of pre-disaster LOC after the disaster, which was evaluated using the survival time analysis. Age, gender, and type of care service were used as covariates. RESULTS: Of the total 193,723 participants, 1,407 (0.7%) were certified disaster victims. Five months after the disaster, 135 (9.6%) of victims and 14,817 (7.7%) of non-victims experienced the rise of LOC. The victim group was significantly more likely to experience an augmentation of LOC than the non-victim group (adjusted hazard ratio 1.24; 95% confidence interval 1.06-1.45). CONCLUSIONS: Older people who were affected by the disaster needed more care than before and the degree of care-need increase was substantially more than non-victims. The result suggests that natural disasters generate more demand for care services among the older people, and incur more resources and cost for society than before.
In this study, we estimated the future emission inventory of primary air pollutants in Japan in 2050 after introducing low-carbon technology based on the results of the socio-economic model provided by the Japanese government. The results suggested that introducing net-zero carbon technology would contribute to a 50-60 % decrease in primary NOx, SO2, and CO emissions and a similar to 30 % decrease in primary emissions of volatile organic compounds (VOCs) and PM2.5. The estimated emission inventory and future meteorological conditions in 2050 were applied as inputs to a chemical transport model. A scenario involving the application of future reduction strategies with relatively moderate global warming (RCP4.5) was evaluated. The results showed that the concentration of tropospheric ozone (O3) was highly reduced compared with that in 2015 after applying net-zero carbon reduction strategies. On the other hand, the fine particulate matter (PM2.5) concentration under the 2050 scenario was expected to be equal or higher because of the growth in secondary aerosol formation caused by the increase in short-wave radiation. Finally, the premature mortal-ity change from 2015 to 2050 was analyzed, and the change in air quality contributed by net-zero carbon technology will contribute to a similar to 4000 decrease in premature deaths in Japan.
Background Despite the impact of heat exposure caused by global warming, few studies have investigated the hourly effects of heat exposure and the risk of cardiovascular disease (CVD) in the elderly. We examined the associations between short-term heat exposure and the risk of CVD in the elderly in Japan and evaluated possible effect-measure modifications by rainy seasons that occur in East Asia. Methods and Results We conducted a time-stratified case-crossover study. The study included 6527 residents in Okayama City, Japan, aged ≥65 years who were transported to emergency hospitals between 2012 and 2019 for the onset of CVD during and a few months after the rainy seasons. We examined the linear associations between temperature and CVD-related emergency calls for each year and for hourly preceding intervals before the emergency call during the most relevant months. Heat exposure during 1 month after the end of the rainy season was associated with CVD risk; the odds ratio (OR) for a 1° C increase in temperature was 1.34 (95% CI, 1.29-1.40). When we further explored the nonlinear association by using the natural cubic spline model, we found a J-shaped relationship. Exposures 0 to 6 hours before the case event (preceding intervals 0-6 hours) were associated with CVD risk, particularly for the preceding interval 0 to 1 hour (OR, 1.33 [95% CI, 1.28-1.39]). For longer periods, the highest risk was at preceding intervals 0 to 23 hours (OR, 1.40 [95% CI, 1.34-1.46]). Conclusions Elderly individuals may be more susceptible to CVD after heat exposure during the month after the rainy season. As shown by finer temporal resolution analyses, short-term exposure to increasing temperature can trigger CVD onset.
The number of patients with heat illness transported by ambulance has been gradually increasing due to global warming. In intense heat waves, it is crucial to accurately estimate the number of cases with heat illness for management of medical resources. Ambient temperature is an essential factor with respect to the number of patients with heat illness, although thermophysiological response is a more relevant factor with respect to causing symptoms. In this study, we computed daily maximum core temperature increase and daily total amount of sweating in a test subject using a large-scale, integrated computational method considering the time course of actual ambient conditions as input. The correlation between the number of transported people and their thermophysiological temperature is evaluated in addition to conventional ambient temperature. With the exception of one prefecture, which features a different Köppen climate classification, the number of transported people in the remaining prefectures, with a Köppen climate classification of Cfa, are well estimated using either ambient temperature or computed core temperature increase and daily amount of sweating. For estimation using ambient temperature, an additional two parameters were needed to obtain comparable accuracy. Even using ambient temperature, the number of transported people can be estimated if the parameters are carefully chosen. This finding is practically useful for the management of ambulance allocation on hot days as well as public enlightenment.
During this age of climate change, the incidence of tropical diseases may change. This study compared the epidemiological characteristics and trends of leptospirosis in Japan between the endemic region, Okinawa, and the rest of the country. Infectious Diseases Weekly Reports were used to determine the numbers and crude incidence rates of leptospirosis. Data were stratified by sex, age, the estimated location of the infection, the notified regions, and the reporting month. A joinpoint regression analysis was performed to estimate the annual percentage change (APC). During the 16-year study period (2006-2021), 543 leptospirosis cases were reported, with male dominance (86.2%). Approximately half of these cases were reported from Okinawa (47.1%). The patients were relatively younger in Okinawa (20-29 years, 23.4%; 30-39 years, 20.7%) than outside Okinawa. The frequency of imported cases was significantly higher outside Okinawa (0.4% versus 14.3%). The incidences of leptospirosis in and outside Okinawa were apparently higher during the summer and typhoon seasons. The annual crude incidence ratios were 20-200 times higher in Okinawa than in the rest of the country. The average APCs for the entire study period in Okinawa and the rest of Japan were 1.6% (95% CI: -5.9 to 9.6) and -1.8% (95% CI: -7.8 to 4.6), respectively, without any particular trends. Collectively, the patient profile of leptospirosis differed between Okinawa (younger men) and outside Okinawa (middle- or older-aged men with a history of traveling abroad). The disease remains a neglected tropical disease; continuous surveillance with close monitoring is required.
Climate change poses significant threats to human health, propelling Japan to take decisive action through the Climate Change Adaptation Act of 2018. This Act has led to the implementation of climate change adaptation policies across various sectors, including healthcare. In this review, we synthesized existing scientific evidence on the impacts of climate change on health in Japan and outlined the adaptation strategies and measures implemented by the central and local governments. The country has prioritized tackling heat-related illness and mortality and undertaken various adaptation measures to mitigate these risks. However, it faces unique challenges due to its super-aged society. Ensuring effective and coordinated strategies to address the growing uncertainties in vulnerability to climate change and the complex intersectoral impacts of disasters remains a critical issue. To combat the additional health risks by climate change, a comprehensive approach embracing adaptation and mitigation policies in the health sector is crucial. Encouraging intersectoral communication and collaboration will be vital for developing coherent and effective strategies to safeguard public health in the face of climate change.
Researchers agree that there is substantial evidence of an increasing trend in both the frequency and duration of extreme temperature events. Increasing extreme temperature events will place more pressure on public health and emergency medical resources, and societies will need to find effective and reliable solutions to adapt to hotter summers. This study developed an effective method to predict the number of daily heat-related ambulance calls. Both national- and regional-level models were developed to evaluate the performance of machine-learning-based methods on heat-related ambulance call prediction. The national model showed a high prediction accuracy and can be applied over most regions, while the regional model showed extremely high prediction accuracy in each corresponding region and reliable accuracy in special cases. We found that the introduction of heatwave features, including accumulated heat stress, heat acclimatization, and optimal temperature, significantly improved prediction accuracy. The adjusted coefficient of determination (adjusted R(2)) of the national model improved from 0.9061 to 0.9659 by including these features, and the adjusted R(2) of the regional model also improved from 0.9102 to 0.9860. Furthermore, we used five bias-corrected global climate models (GCMs) to forecast the total number of summer heat-related ambulance calls under three different future climate scenarios nationally and regionally. Our analysis demonstrated that, at the end of the 21st century, the total number of heat-related ambulance calls in Japan will reach approximately 250,000 per year (nearly four times the current amount) under SSP-5.85. Our results suggest that disaster management agencies can use this highly accurate model to forecast potential high emergency medical resource burden caused by extreme heat events, allowing them to raise and improve public awareness and prepare countermeasures in advance. The method proposed in Japan in this paper can be applied to other countries that have relevant data and weather information systems.
BACKGROUND: Floods and torrential rains are natural disasters caused by climate change. Unfortunately, such events are more frequent and are increasingly severe in recent times. The 2018 Japan Floods in western Japan were one of the largest such disasters. This study aimed to evaluate the effect of the 2018 Japan Floods on healthcare costs and service utilization. METHODS: This retrospective cohort study included all patients whose receipts accrued between July 2017 and June 2019 in Hiroshima, Okayama, and Ehime prefectures using the National Database of Health Insurance Claims. We used Generalized Estimating Equations (GEEs) to investigate yearly healthcare costs during the pre-and post-disaster periods, quarterly high-cost patients (top 10%), and service utilization (outpatient care, inpatient care, and dispensing pharmacy) during the post-disaster period. After the GEEs, we estimated the average marginal effects as the attributable disaster effect. RESULTS: The total number of participants was 5,534,276. Victims accounted for 0.65% of the total number of participants (n = 36,032). Although there was no significant difference in pre-disaster healthcare costs (p = 0.63), post-disaster costs were $3,382 (95% CI: 3,254-3,510) for victims and $3,027 (95% CI: 3,015-3,038) for non-victims (p < 0.001). The highest risk difference among high-cost patients was 0.8% (95% CI: 0.6-1.1) in the fourth quarter. In contrast, the highest risk difference of service utilization was in the first quarter (outpatient care: 7.0% (95% CI: 6.7-7.4), inpatient care: 1.3% (95% CI: 1.1-1.5), and dispensing pharmacy: 5.9% (95% CI: 5.5-6.4)). CONCLUSION: Victims of the 2018 Japan Floods had higher medical costs and used more healthcare services than non-victims. In addition, the risk of higher medical costs was highest at the end of the observation period. It is necessary to estimate the increase in healthcare costs according to the disaster scale and plan for appropriate post-disaster healthcare service delivery.
INTRODUCTION: Torrential rains occurred in Okayama in western Japan in July 2018, forcing local residents to evacuate. Few studies have reported early-phase disease and injury trends among patients following torrential rains. Thus, in this study, we assessed the illness and injury trends among patients who visited temporary medical facilities located in the areas affected by the 2018 torrential rains; these facilities opened 10 d after the disaster. METHODS: We evaluated the trends among patients who visited a medical clinic located in the area in western Japan affected by heavy rains in 2018. We reviewed medical charts related to 1,301 outpatient visits and conducted descriptive analyses. RESULTS: More than half of the patients were over 60 years old. The patients experienced mild injuries (7.9% of total visits) as well as common diseases such as hypertensive diseases (30%), diabetes mellitus (7.8%), acute upper respiratory infections (5.4%), skin diseases (5.4%), and eye diseases (4.8%). Hypertensive diseases were the main cause of a visit in any week. Eye problems were the second-highest reason for a visit in the first week, but there was a relative decrease from the first to the third week. Additionally, the proportion of injuries and skin diseases increased from the first to the second week, from 7.9% to 11.1% for injuries, and from 3.9% to 6.7% for skin diseases. CONCLUSIONS: The types of diseases changed on a weekly basis. Older adults needed medical support for longer than other age groups. Prior preparedness such as earlier deployment of such temporary clinics can help mitigate the damage to the victims.
Leptospirosis is a zoonotic disease that primarily affects people in tropical and subtropical areas worldwide. Owing to the temperate climate of Japan, leptospirosis is not endemic across the country. Domestic cases of leptospirosis have been mainly reported in Okinawa and the southwestern subtropical islands, but not in the other regions. Here, we describe a case of leptospirosis that developed and was diagnosed outside the domestically endemic region. Notably, disease onset occurred shortly after the patient experienced a flood after a typhoon disaster. With global warming, the international prevalence of leptospirosis may change. Physicians outside currently endemic areas must be aware of this tropical disease.
Substantial evidence suggests that non-optimal temperatures can increase the risk of cardiovascular disease (CVD) mortality and morbidity; however, limited studies have reported inconsistent results for hospital admissions depending on study locations, which also lack national-level investigations on cause-specific CVDs. METHODS: We performed a two-stage meta-regression analysis to examine the short-term associations between temperature and acute CVD hospital admissions by specific categories [i.e., ischemic heart disease (IHD), heart failure (HF), and stroke] in 47 prefectures of Japan from 2011 to 2018. First, we estimated the prefecture-specific associations using a time-stratified case-crossover design with a distributed lag nonlinear model. We then used a multivariate meta-regression model to obtain national average associations. RESULTS: During the study period, a total of 4,611,984 CVD admissions were reported. We found cold temperatures significantly increased the risk of total CVD admissions and cause-specific categories. Compared with the minimum hospitalization temperature (MHT) at the 98(th) percentile of temperature (29.9 °C), the cumulative relative risks (RRs) for cold (5(th) percentile, 1.7 °C) and heat (99(th) percentile, 30.5 °C) on total CVD were 1.226 [95% confidence interval (CI): 1.195, 1.258] and 1.000 (95% CI: 0.998, 1.002), respectively. The RR for cold on HF [RR = 1.571 (95% CI: 1.487, 1.660)] was higher than those of IHD [RR = 1.119 (95% CI: 1.040, 1.204)] and stroke [RR = 1.107 (95% CI: 1.062, 1.155)], comparing to their cause-specific MHTs. We also observed that extreme heat increased the risk of HF with RR of 1.030 (95% CI: 1.007, 1.054). Subgroup analysis showed that the age group ≥85 years was more vulnerable to these non-optimal temperature risks. CONCLUSIONS: This study indicated that cold and heat exposure could increase the risk of hospital admissions for CVD, varying depending on the cause-specific categories, which may provide new evidence to reduce the burden of CVD.
It is a well-accepted notion that women are more vulnerable to natural disasters than men, especially in developing countries. However, in developed countries, how women’s empowerment by economic and social development has reduced the gender gap in vulnerability remains insufficiently answered. As Japan passed its golden age, moving into an aging society, a study on how the gender difference in flood vulnerability has evolved can contribute to a better understanding of the types and causes of vulnerability, leading to better flood risk management in a new social context. Following this thinking, the present study conducted a longitudinal analysis using representative flooding cases in Japan over a period of forty years. It found that the women’s fatality rate increased with age much faster than men’s in the 1980s but reversed in a recent major flood disaster. It also revealed that most flood disaster victims were elderly in recent years. These findings suggest that the flood vulnerability at present is more driven by age-related physical ability decline, much less relevant to gender. Based on the results, it proposed a new framework for assessing flood vulnerability in an aging society. Such outcomes can help with the better formulation of flood management policies and probing into solutions.
With the increase in disasters due to climate change, there has been a growing interest in green infrastructures that utilize nature for disaster risk reduction (DRR). However, green infrastructures cannot completely protect against hazards. Therefore, this study investigates the public preference in Japan for DRR and its uncertainty using a survey-based choice experiment. The results showed that benefits were obtained from the increase in “success probability”, “reduction in human damage”, “reduction in property damage”, and “reduction in indirect damage”; however, the benefits obtained from additional improvements diminished. Moreover, the results of our analyses revealed that preferences for DRR and its uncertainty were heterogeneous among respondents, and the population segment that includes more women, older people, and more people who live in areas that may be directly affected by floods had higher ratings for “success probability” and relatively slightly lower ratings for “reduction in indirect damage”.
Climate change is an important issue that affects energy consumption, causes health problems, such as heat stroke, and requires urgent countermeasures. Serious health problems, including cardiac arrest, often occur in winter in traditional residences in Japan. Cooling-heating energy is required to maintain a healthy thermal environment. Although energy efficiency standards for buildings have been introduced worldwide to reduce energy consumption and various passive energy-saving methods are being investigated, traditional residences still face difficulties in conducting renovations because of various restrictions, such as the conservation of historical or aesthetic values. In this study, these issues and their appropriate countermeasures were investigated for a traditional townhouse in Kyoto, Japan, “Kyo-machiya” (including its new form “Heisei-no-Kyo-machiya”). The potential of reducing heating and cooling loads was examined by conducting numerical analysis considering residents’ lifestyles. Field surveys of the indoor environment were conducted in both summer and winter. It was revealed that by optimizing the times and positions of opening and closing the windows and indoor partitions, the indoor air flow could be adjusted from both thermal comfort (cooling in summer) and discomfort (cold drafts in winter) perspectives, leading to improving the indoor environment without using energy.
Objective: Little is known regarding how home care is affected by extreme weather. In February 2018, Fukui City in Japan experienced unprecedented levels of snowfall. We examined snowfall impact on the provision of home care to elucidate whether patients incurred any harm. Methods: A retrospective observational study using clinical and administrative records from a clinic in Fukui City was conducted on 294 patients (mean age = 69.9 +/- 27.7 years; women = 60.5%, median age = 81). The study period was from February 5 to February 18, 2018. We analysed the patients’ characteristics, daily trend of planned/actual patient visits, emergency transportation situations, and local snow accumulation. We summarized the situation in the clinic. Results: There were 326 planned home visits, however only 121 (37%) occurred. Despite this, there were only 2 emergency transfers. Although the available clinical staff was limited, they managed to contact most patients via telephone and social networking services. Conclusion: Although the number of home visits dramatically decreased, the number of emergency transfers did not increase. This study therefore highlights the necessity for effective disaster preparation, such as assessment training, or use of telemedicine, and on-site decision-making to maintain home care during disasters.
OBJECTIVES: Natural disasters can impair the cognitive function of older victims. However, it is unknown whether such natural disasters affect drug treatment for dementia. The aim of this study was to evaluate the effect of the 2018 Japan Floods, the second largest water-related disaster in Japan, on the prescriptions of antidementia drugs (ADD) for older people (≥65 years of age). DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Prescription data in Hiroshima, Okayama, and Ehime prefectures for 1 year before and after the disaster were extracted from the National Database of Health Insurance Claims. From the database, we selected 1,710,119 people age 65 years or over as the study participants. METHODS: In logistic regression models, sex- and age-adjusted odds ratios (ORs) of victims for new ADD prescriptions were calculated. Trends for the ORs before and after the disaster were evaluated using difference-in-difference models. Whether or not there was an increase in the trend for ADD prescriptions (daily dose or number of drug types) was also evaluated among continuous ADD users. RESULTS: Among 1,710,119 participants, 15,994 (0.9%) were recorded as a disaster-victims, and 112,289 (6.6%) were prescribed ADD. Among original nonusers, after the disaster, victims were more likely to start using ADD than nonvictims who had not been affected [adjusted OR = 1.33 (95% CI 1.16-1.52)]. Among continuous users, an increasing trend for ADD prescriptions was more often observed for victims than nonvictims [1.61 (1.13-2.31)]. This effect was robust even after the predisaster trend of ADD use was taken into consideration. CONCLUSIONS AND IMPLICATIONS: The disaster increased the number of users of antidementia medications. The findings suggest the need for evidence-based recommendations to address cognitive impairment among disaster victims, which is lacking in current clinical and disaster guidelines worldwide.
This study examined the relationship between cognitive/structural social capital and post-traumatic stress disorder (PTSD) among victims of heavy rain and flood. Participants were individuals aged≥18 years affected by the July 2018 heavy rainfall in the cities of Kurashiki and Soja, Japan, and living in temporary housing. We distributed five copies of a questionnaire to 1,991 households and received responses from 1,927 individuals (907 men, 1,008 women, 12 respondents of unspecified sex) in 1,029 households (51.7%). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between high (vs. low) social capital and PTSD or other outcomes. After covariate adjustment, the odds of having PTSD were lower in participants with high cognitive social capital than those with low cognitive social capital (OR=0.346, 95%CI: 0.263-0.456). Elderly women with higher structural social capital tended to have lower PTSD odds than those with lower structural social capital (OR=0.671, 95%CI: 0.431-1.046). The opposite pattern was observed for elderly men (OR=1.315, 95%CI: 0.792-2.183). Cognitive social capital is a protective factor that may reduce PTSD or promote a favorable PTSD prognosis after heavy rainfall and flood events. The associations between structural social capital and PTSD differ by age and sex.
Global warming may reduce food production and force people to adopt dietary habits of inadequate quantity or quality. Such dietary habits could trigger chronic kidney disease through inappropriate nutrition or lifestyle diseases. Livestock farming and other types of food production are responsible for many greenhouse gases. These problems are being emphasized as a diet-environment-health trilemma to be addressed on a global scale, with various methods being proposed toward its resolution. Diets like plant-based and low-protein diets not only potentially prevent the progression of chronic kidney disease, but are also rational from an environmental preservation perspective. Evidence from Japan on resolutions for this trilemma is sparse, but one concrete proposal is the use of traditional Japanese diets like washoku, the Okinawa diet, and the traditional Buddhist diet. However, traditional Japanese diets also have several problems, such as excessive salt content and caloric deficiencies, and need to be modified and incorporated into the current lifestyle. The progression of chronic kidney disease needs to be prevented with appropriate dietary treatment and environmental friendly manner.
BACKGROUND: Few studies have investigated the regional variations in the development of neonatal hyperbilirubinemia. This study aimed to investigate regional variations in medical costs for neonatal hyperbilirubinemia and the correlations between sunshine duration and medical care costs for neonatal hyperbilirubinemia in an ecological study, using the National Database of Japan. METHODS: We obtained data on the annual medical costs for neonatal hyperbilirubinemia, annual live births, and annual sunshine duration in each prefecture from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open Data, Vital Statistics in Japan, and System of Social and Demographic Statistics Prefectural Data Basic Data from 2014 to 2017. We created choropleth maps showing the regional variations (quartiles) in the annual medical costs for neonatal hyperbilirubinemia per 10 live births and the annual sunshine duration in each prefecture. We used Pearson’s correlation coefficients to evaluate the associations between the annual sunshine duration and annual medical care costs for neonatal hyperbilirubinemia per 10 live births in each prefecture. RESULTS: The Tohoku region (on the Sea of Japan side) and the Hokuriku region were likely to have higher medical care costs for neonatal hyperbilirubinemia and shorter sunshine duration than the rest of the country. There were weak and negative correlations between the annual sunshine duration and the annual medical care costs for neonatal hyperbilirubinemia. The correlation coefficients ranged from -0.086 to -0.33. CONCLUSION: There could be regional variations in the medical care costs for neonatal hyperbilirubinemia in Japan. Short sunshine duration could be a prognostic factor for the development of neonatal hyperbilirubinemia.
A 16-year-old boy with asthma participated in recovery volunteer work following the 2018 heavy rains in Japan. One month later, he experienced chest pain and dyspnea. Chest computed tomography revealed a cavity with a fungal ball, and Aspergillus fumigatus was detected in his bronchoalveolar lavage fluid. He was treated with voriconazole, but new consolidations appeared rapidly. He also experienced allergic bronchopulmonary aspergillosis. After prednisolone prescription, the consolidations improved; however, his asthma worsened. He underwent partial lung resection to avoid allergens, and his symptoms improved. We must recognize cases of infection after a disaster, especially in patients with chronic respiratory diseases.
BACKGROUND: In metropolitan Tokyo in 2014, Japan experienced its first domestic dengue outbreak since 1945. The objective of the present study was to quantitatively assess the future risk of dengue in Japan using climate change scenarios in a high-resolution geospatial environment by building on a solid theory as a baseline in consideration of future adaptation strategies. METHODS: Using climate change scenarios of the Model for Interdisciplinary Research on Climate version 6 (MIROC6), representative concentration pathway (RCP) 2.6, 4.5, and 8.5, we computed the daily average temperature and embedded this in the effective reproduction number of dengue, R(T), to calculate the extinction probability and interepidemic period across Japan. RESULTS: In June and October, the R(T) with daily average temperature T, was <1 as in 2022; however, an elevation in temperature increased the number of days with R(T) >1 during these months under RCP8.5. The time period with a risk of dengue transmission gradually extended to late spring (April-May) and autumn (October-November). Under the RCP8.5 scenario in 2100, the possibility of no dengue-free months was revealed in part of southernmost Okinawa Prefecture, and the epidemic risk extended to the entire part of northernmost Hokkaido Prefecture. CONCLUSION: Each locality in Japan must formulate action plans in response to the presented scenarios. Our geographic analysis can help local governments to develop adaptation policies that include mosquito breeding site elimination, distribution of adulticides and larvicides, and elevated situation awareness to prevent transmission via bites from Aedes vectors.
It is crucial to provide mental health care following a disaster because the victims tend to experience symptoms such as anxiety and insomnia during the acute phase. However, little research on mental health during the acute phase has been conducted, and reported only in terms of the temporal transition of the number of consultations and symptoms. Thus, the aim of the study was to examine how mental health care needs are accounted for in the overall picture of disaster relief and how they change over time. Using data from the Japanese version of Surveillance in Post-Extreme Emergencies and Disasters (J-SPEED), we assessed the mental health of injured and ill patients to whom Emergency Medical Teams (EMTs) were providing care during the acute period of a disaster. Approximately 10% of all medical consultations were for mental health issues, 83% of which took place within the first 2 weeks after the disaster. The findings showed that, from the start of the response period to the 19th response day, the daily proportion of mental health problems declined substantially, and then gradually increased. Such a V-shaped pattern might be helpful for identifying phase changes and supporting the development of EMT exit strategies.
Several countries have been affected by natural hazards during the COVID-19 pandemic. The combination of the pandemic and natural hazards has led to serious challenges that include financial losses and psychosocial stress. Additionally, this compound disaster affected evacuation decision making, where to evacuate, volunteer participation in mitigation and recovery, volunteer support acceptance, and interest in other hazard risks. This study investigated the impact of COVID-19 on disaster response and recovery from various types of hazards, with regard to preparedness, evacuation, volunteering, early recovery, awareness and knowledge of different types of hazards, and preparedness capacity development. This study targets hazards such as Cyclone Amphan in India, the Kumamoto flood in Japan, Typhoon Rolly in the Philippines, and the California wildfires in the U.S. This study made several recommendations, such as the fact that mental health support must be taken into consideration during COVID-19 recovery. It is necessary to improve the genral condition of evacuation centers in order to encourage people to act immediately. A pandemic situation necessitates a strong communication strategy and campaign with particular regard to the safety of evacuation centers, the necessity of a lockdown, and the duration required for it to reduce the psychological impact. Both national and local governments are expected to strengthen their disaster risk reduction (DRR) capacity, which calls for the multi-hazard management of disaster risk at all levels and across all sectors.
BACKGROUND: Using a population-based stroke registry system, we evaluated the relationship between ambient temperature parameters and stroke incidence in a Japanese population.Methods and Results:We analyzed data from the Takashima Stroke Registry, which records all stroke occurrences in Takashima City, Japan. The study period of 8,401 days was divided into quintiles of daily weather parameters, and the middle quintile was used as the reference category. Incidence rates (IR per 100,000 person-years) were calculated across the quintiles. Poisson regression analysis was used to calculate the effect of temperature parameters on stroke incidence. There were 2,405 first-ever strokes (1,294 men), including 1,625 ischemic, 545 cerebral hemorrhages, 213 subarachnoid hemorrhages, and 22 unclassified strokes. The stroke IR was higher in the middle quintile of average temperature, 357.3 (328.4-388.8), and for other parameters. After adjustment for age and sex, for all stroke, the incidence rate ratio (IRR) in the highest (Q5: IRR 0.81, 95% confidence interval (CI) 0.71-0.92) and the second-highest (Q4: IRR 0.80, 95% CI 0.71-0.91) quintile was lower than that in the middle quintile (Q3: Reference). Analogous results were observed for the minimum, maximum, and lag-days temperatures, also in the subtypes and across ≥65 years of age, also in females. CONCLUSIONS: Higher temperatures, irrespective of the parameter (average, minimum, or maximum), had a protective effect against stroke occurrence in Japan.
OBJECTIVES: To investigate the extent to which temperature and influenza explained seasonality of mortality in Japan and to examine the association of the seasonality with prefecture-specific characteristics. DESIGN: We conducted time-series analysis to estimate the seasonal amplitude before and after adjusting for temperature and/or influenza-like illness (ILI). Next, we applied linear mixed effect models to investigate the association of seasonal amplitudes with each indicator on prefecture-specific characteristics on climate, demographic and socioeconomic factors and adaptations. SETTING: 47 prefectures in Japan PARTICIPANTS: Deaths for all-cause, circulatory, and respiratory disease between 1999 and 2015. OUTCOME MEASURES: Peak-to-trough ratio (PTR, a measure of seasonal amplitude). RESULTS: The nationwide unadjusted-PTRs for all-cause, circulatory and respiratory mortality were 1.29 (95% CIs: 1.28 to 1.31), 1.55 (95% CI: 1.52 to 1.57) and 1.45 (95% CI: 1.43 to 1.48), respectively. These PTRs reduced substantially after adjusting for temperature but very little after a separate adjustment for ILI. Furthermore, seasonal amplitudes varied between prefectures. However, there was no strong evidence for the associations of PTR with the indicators on prefecture-specific characteristics. CONCLUSIONS: Seasonality of mortality is primarily driven by temperature in Japan. The spatial variation in seasonal amplitudes was not associated with prefecture-specific characteristics. Although further investigations are required to confirm our findings, this study can help us gain a better understanding of the mechanisms underlying seasonality of mortality.
OBJECTIVE: Although several studies have reported that some meteorological factors such as ambient temperature and atmospheric pressure, affect the incidence of spontaneous intracerebral hemorrhage (ICH), the correlation remains unclear. This retrospective time-series analysis was aimed to clarify the effects of meteorological parameters on the incidence of ICH. MATERIALS AND METHODS: Data of patients with ICH were obtained from a population-based survey of acute stroke patients between April 2016 and March 2019. All days during the study period were categorized into “no ICH day” when no ICHs occurred, “single ICH day” when only one ICH occurred, and “cluster day” when two or more ICHs occurred. Meteorological data were compared for among the three categories. RESULTS: 1,691 ICH patients from 19 hospitals were registered. In a total of 1,095 days, 250 were categorized as no ICH days, 361 as single ICH days, and 484 as cluster days. Daily ambient temperature declined in parallel with the daily number of ICHs, and it was a significant predictor for single ICH days and cluster days. Furthermore, the incidence of ICH in patients aged 65 years or above, men, those who emerged at home, those with modified Rankin Scale 3-5; and those with hypertension; and ICHs in the basal ganglia, brain stem, and cerebellum were more likely to be affected by low ambient temperature. CONCLUSION: Daily ambient temperature was significantly associated with ICH incidence. Patients’ activity, history of hypertension, and location of hemorrhage were also related to the impact of low ambient temperature on the incidence of ICH.
We investigated decadal (2010-2019) cardiovascular, cerebrovascular, and respiratory mortality sensitivity to annual warm temperatures in major Japanese cities: Sapporo, Tokyo (23 wards), and Osaka. The summer mortalities (June-August) increased with the monthly mean temperature for acute myocardial infarction, other acute ischemic heart diseases, cerebral infarction, and pneumonia in the three cities. Monthly mean temperatures were an indicator of these disease mortalities in Japan. However, similar responses were not found for cardiac arrhythmia and heart failure (excluding Sapporo), subarachnoid hemorrhage, and intracerebral hemorrhage. The decadal sensitivities and risk ratios between the maximum and minimum monthly mean temperatures were calculated using a linear regression model. In Sapporo, Tokyo, and Osaka, for example, the analyses of acute myocardial infarction showed summer positive responses of 0.19-0.25, 0.13-0.18, and 0.12-0.30, respectively, as the mortality rate (per 100,000 population) per 1 degrees C of monthly mean temperature, which estimated increased risks (between the coolest and hottest months) of 37-65% in Sapporo, 31-42% in Tokyo, and 35-39% in Osaka.
OBJECTIVE: This report tries to capture the impact of the Project for Strengthening the ASEAN Regional Capacity on Disaster Health Management (ARCH Project) in each ASEAN Member State (AMS) and Japan as a result of the ARCH Project implementation since July 2016. METHODS: Impact on AMS: The analysis of the impact on AMS was based on a comparison of the impact of the project on management and coordination of Emergency Medical Teams (EMTs), and application of the project outcome in actual emergency operations compared to the previous status in each AMS.Impact on Japan: The history of the development of disaster medicine in Japan was reviewed, with an aim to analyze the impact of supporting AMS through the ARCH Project on Japan, and the possibility of bi-directional cooperation in the future. RESULTS: Impact on AMS: Since the initiation of the ARCH Project, AMS has made significant progress in WHO EMT accreditation, strengthening EMTCC capacity for receiving international assistance, as well as the development of legislation or strategic plans related to DHM, and application of the Project products such as standard operating procedures or regional tools in actual disasters/emergencies.Impact on Japan: Disaster medicine in Japan originated from the Cambodian refugees’ relief mission in 1979. Since then, the management system has been strengthened including the foundation of the Japan Disaster Relief (JDR) Team, a structure with a legal foundation. The experience gained through international operations has contributed to the development of Japan’s domestic disaster response system. Japan learned the operational effectiveness of the post-disaster health surveillance system through the disaster response operation in 2013 Typhoon Yolanda Disaster in Philippines and introduced a modified system in Japan for domestic disaster response, which was later refined and proposed for an international standard. CONCLUSION: ARCH Project is highly appreciated by AMS as the opportunity to share knowledge and experience among countries and thereby contributing to achieving the “One ASEAN, One Response” concept, as well as the driving force for each AMS to develop its capacity in DHM. While the ARCH Project started to support AMS to strengthen its regional capacity in disaster health management, it is important to build a bi-directional relationship between ASEAN and Japan in terms of mutual learning and support to tackle future disasters.
BACKGROUND: The incidence of acute cholecystitis has a seasonal peak in summer. However, the reason for such seasonality remains unclear. This retrospective cohort study was performed to examine the association between ambient temperature and acute cholecystitis. METHODS: We identified admissions for acute cholecystitis from January 2011 to December 2017 from a nationwide inpatient database in Japan. We performed a Poisson regression analysis to investigate the association between ambient temperature and admission for acute cholecystitis with adjustment for relative humidity, national holidays, day of the week, and year. We accounted for clustering of the outcome within prefectures using a generalized estimating equation. RESULTS: We analyzed 601 665 admissions for acute cholecystitis. With an ambient temperature of 5.0 °C-9.9 °C as a reference, Poisson regression showed that the number of admissions increased significantly with increasing temperature (highest above 30 °C; relative risk, 1.35; 95% confidence interval, 1.34-1.37). An ambient temperature of <5.0 °C was also associated with higher admission for acute cholecystitis than an ambient temperature of 5.0 °C-9.9 °C (relative risk, 1.23; 95% confidence interval, 1.21-1.25). CONCLUSION: The present nationwide Japanese inpatient database study showed that high temperature (≥10.0 °C) and low temperature (<5.0 °C) were associated with increased admission for acute cholecystitis.
AIM: Issuance of the WHO Housing and health guidelines has paralleled growing interest in the housing environment. Despite accumulating evidence of an association between outdoor temperature and serum cholesterol, indoor temperature has not been well investigated. This study examined the association between indoor temperature and serum cholesterol. METHODS: We collected valid health checkup data of 2004 participants (1333 households), measured the indoor temperature for 2 weeks in winter, and divided participants according to whether they lived in a warm (average bedroom temperature ≥ 18℃), slightly cold (12-18℃) or cold house (＜12˚C). The relationship between bedroom temperature and serum cholesterol was analyzed using multivariate logistic regression models, adjusting for demographics, lifestyle habits and the season in which the health checkup was conducted, with a random effect of climate areas in Japan. RESULTS: The sample sizes for warm, slightly cold, and cold houses were 206, 940, and 858, respectively. Compared to those in warm houses, the odds ratio of total cholesterol exceeding 220 mg/dL was 1.83 (95%CI: 1.23-2.71, p=0.003) for participants in slightly cold houses and 1.87 (95%CI: 1.25-2.80, p=0.002) in cold houses. Similarly, the odds ratio of LDL/non-HDL cholesterol exceeding the standard range was 1.49 (p=0.056)/1.67 (p=0.035) for those in slightly cold houses and 1.64 (p=0.020)/1.77 (p=0.021) in cold houses. HDL cholesterol and triglycerides were not significantly associated with bedroom temperature. CONCLUSION: Besides lifestyle modification, improving indoor thermal environment through strategies such as installing high thermal insulation and appropriate use of heating devices may contribute to better serum cholesterol condition.
BACKGROUND: Evidence on whether meteorological conditions affect hip fractures (HFs) is limited. This study aimed to clarify the associations between ambient temperature and sun exposure and HFs in Japan. METHODS: Record of daily hospital admissions for HFs between 2015 and 2018 were extracted from a Japanese nationwide inpatient database. We conducted a time-series quasi-Poisson regression analysis using a distributed lag non-linear model with lag 0-39 days to estimate prefecture-specific relative risks (RRs) of HFs. We also estimated pooled RRs using random-effects meta-analysis. RESULTS: We identified 355,563 HFs. For mean temperature, immediate RRs (lag 0-2 days) were 1.349 (95% confidence interval (CI): 1.305, 1.395) and 0.754 (95% CI: 0.727, 0.782) for low (mean of the 2.5th percentile) and high (mean of the 97.5th percentile) mean temperature, respectively, relative to the reference (mean of medians). For sunshine duration, immediate RRs were 0.929 (95% CI: 0.913, 0.946) and 1.056 (95% CI: 1.029, 1.085) for short (mean of the 2.5th percentile) and long (mean of the 97.5th percentile) sunshine duration, respectively, and delayed RRs (lag 3-39 days) was 0.770 (95% CI: 0.696, 0.851) for long sunshine duration relative to the reference (mean of medians). Immediate RRs were larger for both exposures in patients admitted from home than in those from care facilities. CONCLUSIONS: Lower mean temperature and longer sunshine duration were associated with immediate higher HF risks. Higher mean temperature and shorter sunshine duration were associated with immediate lower HF risks. These associations were modified by admission routes. Longer sunshine duration was also associated with delayed lower HF risks.
BACKGROUND: Most older people with disabilities or illnesses continue to use long-term care (LTC) services for the rest of their lives. However, disasters can cause a discontinuation of LTC services, which usually means tragic outcomes of affected persons. In view of the recent progression of population aging and the increase in natural disasters, this study focuses on the impact of disasters on older people’s discontinuation of LTC services, and those more risk of such discontinuation than others. However, current evidence is scarce. METHODS: We conducted a retrospective cohort study with 259,081 subjects, 2,762 of whom had been affected by disaster and 256,319 who had not been affected during the 2018 Japan Floods. The sample in the three most disaster-affected prefectures was drawn from the Long-term Care Insurance Comprehensive Database and included older people certified with care-need level. The observation period was two months before the disaster and five months after it. We calculated the hazard ratio (HR) of municipality-certified subjects affected by the disaster versus those who were not. Subgroup analyses were conducted for categories of individual-, facility- and region-associated factors. RESULTS: Affected persons were twice as likely to discontinue LTC services than those who were not affected (adjusted HR, 2.06 95% CI, 1.91-2.23). 34% of affected persons whose facilities were closed discontinued their LTC services at five months after the disaster. A subgroup analysis showed that the risk of discontinuing LTC services for affected persons compared to those who were not affected in the relatively younger subgroup (age < 80: adjusted HR, 2.55; 95% CI, 2.20-2.96 vs. age ≥ 80 : 1.91; 1.75-2.10), and the subgroup requiring a lower level of care (low: 3.16; 2.74-3.66 vs. high: 1.71; 1.50-1.96) were more likely to discontinue than the older and higher care level subgroups. CONCLUSIONS: A natural disaster has a significant effect on the older people's discontinuation of LTC services. The discontinuations are supposedly caused by affected persons' death, hospitalization, forced relocation of individuals, or the service provider's incapacity. Accordingly, it is important to recognize the risk of disasters and take measures to avoid discontinuation to protect older persons' quality of life.
Some cardiovascular and respiratory diseases are triggered by changes in ambient temperature or extremes of temperature. This study aimed to clarify the changes in mortality associated with temperature-sensitive diseases in Japan during the COVID-19 pandemic. We used data from three major cities (Sapporo City, Tokyo 23 wards, and Osaka City) from 2010 to 2019 to determine disease mortality rates and monthly mean temperatures from April to December. If the pandemic had not occurred in 2020, the results showed that temperature-sensitive disease death counts would have increased from 324 to 980, based on a 95% confidence interval estimated from the past 10 years in Sapporo (19-56% increase in actual deaths from 2020), from 651 to 2,653 in Tokyo (10-39% increase), and from 235 to 1,343 in Osaka (8-48% increase). Analyses of meshed population data during the COVID-19 pandemic indicated that inhibiting people’s behaviour and outdoor mobility, especially in older men, caused a decrease in mortality.
BACKGROUND: Chronologically meteorological and calendar factors were risks of stroke occurrence. However, the prediction of stroke occurrences is difficult depending on only meteorological and calendar factors. We tried to make prediction models for stroke occurrences using deep learning (DL) software, Prediction One (Sony Network Communications Inc., Tokyo, Japan), with those variables. METHODS: We retrospectively investigated the daily stroke occurrences between 2017 and 2019. We used Prediction One software to make the prediction models for daily stroke occurrences (present or absent) using 221 chronologically meteorological and calendar factors. We made a prediction models from the 3-year dataset and evaluated their accuracies using the internal cross-validation. Areas under the curves (AUCs) of receiver operating characteristic curves were used as accuracies. RESULTS: The 371 cerebral infarction (CI), 184 intracerebral hemorrhage (ICH), and 53 subarachnoid hemorrhage patients were included in the study. The AUCs of the several DL-based prediction models for all stroke occurrences were 0.532-0.757. Those for CI were 0.600-0.782. Those for ICH were 0.714-0.988. CONCLUSION: Our preliminary results suggested a probability of the DL-based prediction models for stroke occurrence only by meteorological and calendar factors. In the future, by synchronizing a variety of medical information among the electronic medical records and personal smartphones as well as integrating the physical activities or meteorological conditions in real time, the prediction of stroke occurrence could be performed with high accuracy, to save medical resources, to have patients care for themselves, and to perform efficient medicine.
This study analyzed the support activities that the Disaster Psychiatric Assistance Team (DPAT) in Japan provided following four previous disasters (a volcanic eruption, a mudslide, a flood, and an earthquake) to identify links between the disaster type and the characteristics of acute stage mental disorders observed. Using Disaster Mental Health Information Support System database records of consultations with patients supported by the DPAT during the survey period from 2013 (when DPAT was launched) to 2016, we performed cross-tabulations and investigated significant differences using chi-squared tests. For expected values less than 5, Fisher’s exact test was performed. Frequently occurring acute-stage symptoms after a disaster include anxiety, sleep problems, mood and affect, and physical symptoms. The affected population characteristics, victim attributes, severity of damage sustained, and evacuation status were the chief factors that influenced acute-stage mental health symptoms. The psychiatric symptoms detected in our study together with the results of diagnoses are important for determining the types of early interventions needed during the acute stage of a disaster. By sharing baseline mental health information, together with disaster-related characteristics highlighted in this study, mental health providers are better able to predict future possible mental disorders and symptoms.
BACKGROUND: Although substantial evidence suggests that high and low temperatures are adversely associated with nonaccidental mortality, few studies have focused on exploring the risks of temperature on external causes of death. OBJECTIVES: We investigated the short-term associations between temperature and external causes of death and four specific categories (suicide, transport, falls, and drowning) in 47 prefectures of Japan from 1979 to 2015. METHODS: We conducted a two-stage meta-regression analysis. First, we performed time-stratified case-crossover analyses with a distributed lag nonlinear model to examine the association between temperature and mortality due to external causes for each prefecture. We then used a multivariate meta-regression model to combine the association estimates across all prefectures in Japan. In addition, we performed stratified analyses for the associations by sex and age. RESULTS: A total of 2,416,707 external causes of death were included in the study. We found a J-shaped exposure-response curve for all external causes of death, in which the risks increased for mild cold temperatures [20th percentile; relative risk (RR) = 1.09 (95% confidence interval [CI]: 1.05,1.12)] and extreme heat [99th percentile; RR = 1.24 (95% CI: 1.20, 1.29)] compared with those for minimum mortality temperature (MMT). However, the shapes of the exposure-response curves varied according to four subcategories. The risks of suicide and transport monotonically increased as temperature increased, with RRs of 1.35 (95% CI: 1.26, 1.45) and 1.60 (95% CI: 1.35, 1.90), respectively, for heat, whereas J- and U-shaped curves were observed for falls and drowning, with RRs of 1.14 (95% CI: 1.03, 1.26) and 1.95 (95% CI: 1.70, 2.23) for heat and 1.13 (95% CI: 1.02, 1.26) and 2.33 (95% CI: 1.89, 2.88) for cold, respectively, compared with those for cause-specific MMTs. The sex- and age-specific associations varied considerably depending on the specific causes. DISCUSSION: Both low and high temperatures may be important drivers of increased risk of external causes of death. We suggest that preventive measures against external causes of death should be considered in adaptation policies. https://doi.org/10.1289/EHP9943.
Landslides are natural hazards that cause severe damage and human losses. Japan has succeeded in reducing the number of landslide fatalities and is one of the few countries with long-term databases of landslide fatalities. In this study, we identified the factors that contributed to the decrease in fatalities associated with rainfall-triggered landslides in Japan between 1945 and 2019. We examined trends in landslide fatalities and six factors for Periods I, II, III, IV, and V-each period spans 15 years of the study period-and for Periods I-II, II-III, III-IV, and IV-V. We examined the trends in the number of landslides (N(L)) and in the ratio between the number of fatalities (N(F)) and the number of landslides (N(F)/N(L)), and considered fatalities as the product of the number of landslides and the probability of fatalities. The number of fatalities decreased continuously between Periods I and IV; the rate of the decrease declined over time. During Period I-II, N(F)/N(L) decreased, whereas N(L) remained unchanged. Decreases in the average number of household members, changes in building structure, and increases in the number of people evacuated may have contributed to the decrease in N(F)/N(L). During Periods II-III and III-IV, N(L) also decreased. During Period II-III, the area of mature forests increased slowly. During Period III-IV, the implementation of structural measures (i.e., hard measures) was aggressively pursued. The factors that contributed to the decrease in landslide fatalities changed with time, suggesting that measures for reducing landslide fatalities changed according to the degree of maturity of the nation. Furthermore, we identified increases in rainfall and N(L) in Period V, which might indicate a future increase in landslide fatalities.
The Miyako Islands (with a population of approximately 50,000) are located in southwestern Japan, with a subtropical oceanic climate. This isolated location permitted a retrospective population-based epidemiological study of subarachnoid hemorrhage. We retrospectively enrolled 110 consecutive patients from 2010 to 2019 using the subarachnoid hemorrhage database at Okinawa Miyako Hospital, which is the only local facility with neurosurgeons. We calculated the incidence of subarachnoid hemorrhage standardized to the entire Japanese population. The seasonal distribution of subarachnoid hemorrhage onset and patients’ epidemiological characteristics were also investigated. The standardized annual incidence of subarachnoid hemorrhage was 21.4 per 100,000 population, as reported previously in Japan. The patients’ mean age was 62.1 ± 15.4 years, and women constituted 60.9%. Anterior communicating artery aneurysms were most common. The endovascular treatment for ruptured aneurysms was increasing as standard levels in Japan. The rates of symptomatic vasospasm and secondary hydrocephalus requiring additional neurosurgical treatment were 2.7% and 19.1%, respectively. The mortality rate was 23.6%. The percentage of patients with a modified Rankin scale score of 0-2 at discharge was 55.5%. There were no differences in the frequency of subarachnoid hemorrhage associated with seasonal distribution or climatic factors. The incidence, baseline characteristics, and clinical outcomes of subarachnoid hemorrhage in the Miyako Islands were similar to those in other regions of Japan. There are preferable epidemiological backgrounds for further practical clinical research.
BACKGROUND: The Reiwa First Year East Japan Typhoon of 2019 caused a torrential flood in Japan. In Nagano City, a large area was flooded due to the collapse of the Chikuma River embankment. After large-scale disasters, an increase in cardiovascular and cerebrovascular events has been reported on account of the stressful conditions. However, few reports of disaster-related diseases associated with flood damage have been described. Thus, our aim was to elucidate the effect of floods on the incidences of cardiovascular and cerebrovascular diseases in Nagano City. METHODS: The Shinshu Assessment of Flood Disaster Cardiovascular Events (SAVE) trial enrolled 2,426 patients admitted for cardiovascular or cerebrovascular diseases at all five hospitals with an emergency department in Nagano City from October 1 to December 31 in the years 2017, 2018, and 2019. The occurrence of these diseases was calculated in every 2 weeks and the findings of 2019 (year of the flood) were compared with those of 2017 and 2018. RESULTS: Cardiovascular and cerebrovascular diseases significantly increased during the 2 weeks immediately after the flood disaster (149 in 2019 vs average of 116.5 in the previous 2 years, p < 0.05). Unstable angina cases significantly increased 1.5-2 months after the flood disaster, and cerebral hemorrhage cases significantly increased in the 2 weeks after the flood disaster. CONCLUSIONS: Cardiovascular and cerebrovascular events increased significantly during the 2 weeks immediately after the large-scale flood disaster caused by the Reiwa First Year East Japan typhoon. Because of the increasing frequency of flood disasters, it is necessary to predict the occurrences of cardiovascular and cerebrovascular diseases and to implement guidelines for their appropriate and timely management.
OBJECTIVE: Typhoon Hagibis struck Japan on October 12, 2019. This study documents and characterizes deaths caused by Hagibis and helps identify strategies to reduce mortality in future disasters. METHODS: Japanese residents, who were killed by Typhoon Hagibis, as reported by Japan’s Fire and Disaster Management Agency, were considered for the study. Details were collected from mainstream Japanese media, and flooding data from hazard maps published by local municipalities. RESULTS: Out of the 99 total fatalities, 65 (73.0%) were aged 65 years or above. Among those who drowned indoors (20), 18 (90.0%) lived in high-risk areas of flooding, and their bodies were found on the first floor of their residences. A total of 10 (55.6%) out of the 18 fatalities lived in homes with 2 or more floors, indicating that they could have moved upstairs to avoid the floodwater. However, 6 (33.3%) could not do so due to existing health issues. CONCLUSIONS: Relatively elderly people, particularly those in areas at high risk of flooding, were most affected. Seeking higher ground is a standard safety measure in times of flooding, but this may not be possible for everyone depending on their health status, structure of their residence, and the depth of floodwaters.
OBJECTIVE: To determine the impact of the 2018 Japan Floods, one of the largest water disasters in Japan, on the number of prescriptions for triptans and ergotamine (acute treatment). BACKGROUND: Natural disasters frequently occur worldwide and may cause psychological stress-related diseases. Acute migraine attacks can be triggered by psychological stress. Disaster victims are likely to experience tremendous psychological stress; however, the relationship between natural disasters and migraine attacks is not well investigated. METHODS: A retrospective longitudinal cohort study was conducted using the National Database of Health Insurance Claims in the hardest-hit areas of the disaster 1 year before and after the disaster. We included people between the ages of 15 and 64 years. Those who had a victim code that was certificated by a local government were assigned to the victim group, and others to the nonvictim group. For those who were not prescribed acute treatment before the disaster (i.e., group without previous acute treatment), the cumulative incidence of new prescriptions for acute treatment at 12 months of follow-up was calculated and compared between victims and nonvictims with survival analysis. RESULTS: Of 3,475,515 people aged 15 to 64 years enrolled in the study, 16,103 (0.46%) were assigned to the victim group. In the group without previous acute treatment, 111 (0.70%) of 15,933 victims and 14,626 (0.43%) of 3,431,423 nonvictims were newly prescribed acute treatment after the disaster, and new prescriptions for acute treatment were significantly more likely to occur in victims than in nonvictims (adjusted hazard ratio, 1.68; 95% CI, 1.39-2.02). CONCLUSIONS: The 2018 Japan Floods increased the number of prescriptions for acute migraine medications among victims, suggesting that acute migraine attacks occurred more frequently after a natural disaster.
INTRODUCTION: Rainfall-induced floods and landslides accounted for 20.7% of all disaster events in Japan from 1985 through 2018 and caused a variety of health problems, both directly and indirectly, including injuries, infectious diseases, exacerbation of pre-existing medical conditions, and psychological issues. More evidence of health problems caused by floods or heavy rain is needed to improve preparedness and preventive measures; however, collecting health data surrounding disaster events is a major challenge due to environmental hazards, logistical constraints, political and economic issues, difficulties in communication among stakeholders, and cultural barriers. In response to the West Japan Heavy Rain in July 2018, Emergency Medical Teams (EMTs) used Japan – Surveillance in Post-Extreme Emergencies and Disasters (J-SPEED) as a daily reporting template, collecting data on the number and type of patients they treated and sending it to an EMT coordination cell (EMTCC) during the response. STUDY OBJECTIVE: The aim of the study was to conduct a descriptive epidemiology study using J-SPEED data to better understand the health problems during floods and heavy rain disasters. METHODS: The number and types of health problems treated by EMTs in accordance with the J-SPEED (Ver 1.0) form were reported daily by 85 EMTs to an EMTCC, where data were compiled during the West Japan Heavy Rain from July 8 through September 11, 2018. Reported items in the J-SPEED form were analyzed by age, gender, area (prefecture), and time period. RESULTS: The analysis of J-SPEED data from the West Japan Heavy Rain 2018 revealed the characteristics of a total of 3,617 consultations with the highest number of consultations (2,579; 71.3%) occurring between Day 5 and Day 12 of the 65-day EMT response. During the response period, skin disease was the most frequently reported health event (17.3%), followed by wounds (14.3%), disaster stress-related symptoms (10.0%), conjunctivitis (6.3%), and acute respiratory infections (ARI; 5.4%). CONCLUSION: During the response period, skin disease was the most frequently reported health event, followed by wounds, stress, conjunctivitis, and ARIs. The health impacts of a natural disaster are determined by a variety of factors, and the current study’s findings are highly context dependent; however, it is expected that as more data are gathered, the consistency of finding will increase.
BACKGROUND: The frequency and intensity of natural disasters are increasing worldwide, which makes our understanding of disaster-related diseases more important than ever. Natural disasters cause mental stress and infectious diarrhea, but the causal relationship between disasters and a potential consequence of these conditions, irritable bowel syndrome (IBS), is unreported. The 2018 Japan Floods, which took place in July 2018 was one of the largest water disasters in Japan’s recorded history. We investigate the change of drug prescriptions for IBS between disaster-suffers and non-sufferers throughout the disaster period to examine the relationship. METHODS: This is a retrospective cohort study based on the Japanese National Database of Health Insurance Claims and Specific Health Checkups in flood-stricken areas between July 2017 and June 2019. We included subjects older than 15 years of age who had visited a medical institution or been hospitalized in the hardest-hit areas of the disaster. Ramosetron, polycarbophil calcium, and mepenzolate bromide (IBS drugs) approved solely for the treatment of IBS in Japan were analyzed. The monthly rate of prescriptions for IBS drugs was compared between municipality-certified disaster victims and non-victims using a controlled interrupted time series analysis. For those who were not prescribed IBS drugs before the disaster (non-users), the occurrence of an IBS drug prescription after the disaster was evaluated using a multivariable logistic regression analysis adjusted for gender and age. RESULTS: Of 5,287,888 people enrolled, 32,499 (0.61%) were certified victims. The prescription rate for IBS drugs among victims increased significantly by 128% immediately after the disaster, while it was stable among non-victims. The trend for the post-disaster prescription rate among victims moved upward significantly when compared to non-victims (0.01% per month; 95% confidence interval (CI) 0.004-0.015; P = 0.001). Among non-users, the occurrence of an IBS drug prescription for victims was 0.71% and was significantly higher than non-victims (0.35%, adjusted odds ratio 2.05; 95% CI 1.81-2.32). CONCLUSIONS: The 2018 Japan Floods increased the rate of prescriptions for IBS drugs, suggesting that the disaster caused or worsened IBS among victims.
BACKGROUND: The July 2018 Japan Floods caused enormous damage to western Japan. Such disasters can especially impact elderly persons. Research has shown that natural disasters exacerbated a decline in cognitive function, but to date, there have been no studies examining the effects of this disaster on the elderly. The object of this study was to reveal the effect of this disaster in terms of cognitive decline among the elderly. METHODS: Study participants were certified users of the long-term care insurance (LTCI) system in Hiroshima, Okayama, and Ehime prefectures from May 2018 to June 2018. The observation period was from July 2018 to December 2018. Our primary outcome was cognitive decline after the disaster using a dementia symptomatology assessment. In addition to a crude model, a multivariate Cox proportional hazards model was used to assess the cognitive decline of victims, adjusting for age classification, gender, the level of dementia scale before the disaster occurred, residential environment, whether a participant used facilities shut down after the disaster, and population density. After we confirmed that the interaction term between victims and residential environment was statistically significant, we stratified them for the analysis. RESULTS: The total number of participants was 264,614. Victims accounted for 1.10% of the total participants (n = 2,908). For the Cox proportional hazards model, the hazard ratio of the victims was 1.18 (95% confidential interval (CI): 1.05-1.32) in the crude model and 1.12 (95% CI: 1.00-1.26) in the adjusted model. After being stratified by residential environment, the hazard ratio of home victims was 1.20 (95% CI: 1.06-1.36) and the hazard ratio of facility victims was 0.89 (95% CI: 0.67-1.17). CONCLUSIONS: This study showed that elderly living at home during the 2018 Japan Floods were at risk for cognitive decline. Medical providers, care providers, and local governments should establish a system to check on the cognitive function of elderly victims and provide necessary care support.
OBJECTIVE: The impact of the 2018 Japan Floods on prescriptions of Yokukansan was evaluated. METHODS: This was a retrospective cohort study based on the National Database of Health Insurance Claims which covers all the prescriptions issued in Japan. Participants were patients aged 65 or older who received any medical care at medical institutions located in the three most-severely affected prefectures between 1 year before and after the disaster. We analyzed the number of new prescriptions of Yokukansan and other Kampo drugs among those who had not been prescribed any Kampo for 1 year before the disaster. Kaplan-Meier analysis and a Cox proportional hazards model were used to evaluate the risk of the disaster for a new prescription. RESULTS: Subjects comprised 1,372,417 people (including 12,787 victims, 0.93%). The hazard ratio (HR) of the disaster for Yokukansan prescriptions was 1.49 [95% confidence intervals (CI): 1.25-1.78], and 1.54 (95% CI: 1.29-1.84) in the crude and age-sex adjusted model, respectively. The HR of the disaster for prescription of other Kampo drugs in the crude and adjusted model was 1.33 (95% CI: 1.27-1.39), and 1.32 (95% CI: 1.27-1.38), respectively. The magnitude of increase of victims prescribed Yokukansan (31.4%) was statistically higher than for those prescribed other Kampo drugs (19.3%) (p < 0.001). CONCLUSION: The disaster increased prescriptions of both Yokukansan and other Kampo drugs among elderly victims. The increase was more remarkable in Yokukansan than other Kampo drugs. Clinicians and policymakers should be aware of the increased need for Yokukansan in times of natural disaster.
PURPOSE: Natural disaster has an impact on mental health. The 2018 Japan Floods, which took place in July 2018 were one of the largest water disasters in Japan’s recorded history. We aimed to evaluate the change in the number of benzodiazepine prescriptions by physicians before and after the disaster. METHODS: A retrospective cohort study based on the National Database of Health Insurance Claims was conducted in the flood-stricken areas between July 2017 and June 2019. The subjects were divided between victims and non-victims according to certification by local governments. Members of both groups were then categorized into three groups based on their pre-flood use of benzodiazepines: non-user, occasional user, and continuous user. Difference-in-differences (DID) analysis with a logistic regression model was conducted to estimate the effect of the disaster among victims by comparing the occurrence of benzodiazepine prescriptions before and after the disaster. RESULTS: Of 5,000,129 people enrolled, 31,235 were victims. Among all participants, the mean prescription rate for benzodiazepines in victims before the disaster (11.3%) increased to 11.8% after the disaster, while that in non-victims (8.3%) decreased to 7.9%. The DID analysis revealed that benzodiazepine prescription among victims significantly increased immediately after the disaster (adjusted ratio of odds ratios (ROR) 1.07: 95% confidence interval 1.05-1.11), and the effect of the disaster persisted even 1 year after the disaster (adjusted ROR 1.2: 95% confidence interval 1.16-1.24). CONCLUSION: The flood increased the number of benzodiazepines prescriptions among victims, and the effect persisted for at least 1 year.
The estimation of heat-related illness cases is a key factor in proposing and implementing suitable intervention strategies and healthcare resource management. This paper proposes new frameworks to estimate the number of patients with heat-related illnesses by administrative wards in Nagoya City using 2014-2019 data. The proposed frameworks are based on the derivation of estimation formulae and machine learning. The daily residual estimation error in the 16 wards was less than one person with both the frameworks. The daily working time average ambient temperature may yield a better correlation than the daily average temperature or daily highest temperature with the number of patients transported by an ambulance from outdoor sites. The results also indicate that patients transported from indoor sites are influenced by earlier ambient conditions over approximately 50 days. In contrast, those transported from outdoor sites are influenced by a relatively short period (20 days), which may correspond to heat adaptation. The frameworks provide a better understanding of the different factors that would lead to an accurate prediction of the number of cases of heat-related patients from weather forecasts. These findings would lead to efficient ambulance allocation as well as public awareness on hot days to suppress heat-related morbidity.
With an increase in the aging population in many countries worldwide, much attention is being paid to the study of thermal comfort for the elderly. Because the elderly spend most of their time indoors, the demand for air conditioning is expected to increase, and it is important to study the thermal comfort of the elderly and appropriate operation plans for air conditioning. In this study, we conducted a field survey of thermal comfort and building energy simulation for an air-conditioned nursing home in Nagano, Japan. The field survey was conducted between June 2020 and June 2021. Over 80% of the subjects were satisfied with the indoor thermal environment. The thermal neutral temperature of the elderly was 25.9 degrees C in summer and 23.8 degrees C in winter. Future weather data was used to predict the future heating and cooling loads of the nursing home. The results showed that the total heat load may not change significantly, as the decrease in heating load compensates for the increase in cooling load. This study will serve as a useful reference for a wide range of stakeholders, including managers and designers of nursing homes.
BACKGROUND: Predictive scenarios of heatstroke over the long-term future have yet to be formulated. The purpose of the present study was to generate baseline scenarios of heat-related ambulance transportations using climate change scenario datasets in Tokyo, Japan. METHODS: Data on the number of heat-related ambulance transportations in Tokyo from 2015 to 2019 were examined, and the relationship between the risk of heat-related ambulance transportations and the daily maximum wet-bulb globe temperature (WBGT) was modeled using three simple dose-response models. To quantify the risk of heatstroke, future climatological variables were then retrieved to compute the WBGT up to the year 2100 from climate change scenarios (i.e., RCP2.6, RCP4.5, and RCP8.5) using two scenario models. The predicted risk of heat-related ambulance transportations was embedded onto the future age-specific projected population. RESULTS: The proportion of the number of days with a WBGT above 28°C is predicted to increase every five years by 0.16% for RCP2.6, 0.31% for RCP4.5, and 0.68% for RCP8.5. In 2100, compared with 2000, the number of heat-related ambulance transportations is predicted to be more than three times greater among people aged 0-64 years and six times greater among people aged 65 years or older. The variance of the heatstroke risk becomes greater as the WBGT increases. CONCLUSIONS: The increased risk of heatstroke for the long-term future was demonstrated using a simple statistical approach. Even with the RCP2.6 scenario, with the mildest impact of global warming, the risk of heatstroke is expected to increase. The future course of heatstroke predicted by our approach acts as a baseline for future studies.
The purpose of this study was to quantify the sleep disturbances caused by climate change using disability-adjusted life years (DALY). The revised sleep quality index for daily sleep (SQIDS2), a self-administered questionnaire for daily sleep quality, was developed to assess daily sleep disturbances. This questionnaire referenced and simplified the Pittsburgh Sleep Quality Index (PSQI). This study was conducted in Nagoya City in August 2011 and 2012. Sleep quality was measured using SQIDS2 and PSQI. A total of 574 participants in 2011 and 710 in 2012 responded to the survey. The sleep disturbance prevalence calculated from the SQIDS2 score was correlated with the daily minimum temperature (p = 0.0067). This score increased when the daily minimum temperature was above 24.8 degrees C. When correcting for the PSQI score, DALY loss due to heat-related sleep disturbances in Nagoya City (population: 2,266,851) was estimated to be 81.8 years in 2012. This value was comparable to the DALY loss due to heatstroke. Sleep disturbance due to climate change was quantified using the DALY based on the PSQI. Legislators must recognize the critical impact of the damage caused by sleep disturbances due to high temperatures at night. Additionally, a daily minimum temperature of 25 degrees C should be the starting point when establishing a goal or guideline for nighttime temperature.
An increase in the global surface temperature and changes in urban morphologies are associated with increased heat stress especially in urban areas. This can be one of the contributing factors underlying an increase in heat strokes. We examined the impact of summer minimum air temperatures, which often represent nighttime temperatures, as well as a maximum temperature on a heat stroke. We collected data from the records of daily ambulance transports for heat strokes and meteorological data for July and August of 2017-2019 in the Tottori Prefecture, Japan. A time-stratified case-crossover design was used to determine the association of maximum/minimum air temperatures and the incidence of heat strokes. We used a logistic regression to identify factors associated with the severity of heat strokes. A total of 1108 cases were identified with 373 (33.7%) calls originating in the home (of these, 59.8% were the age of ≥ 75). A total of 65.8% of cases under the age of 18 were related to exercise. Days with a minimum temperature ≥ 25 °C had an odds ratio (95% confidence interval) of 3.77 (2.19, 6.51) for the incidence of an exercise-related heat stroke (reference: days with a minimum temperature < 23 °C). The odds ratio for a heat stroke occurring at home or for calls for an ambulance to the home was 6.75 (4.47, 10.20). The severity of the heat stroke was associated with older age but not with air temperature. Minimum and maximum air temperatures may be associated with the incidence of heat strokes and in particular the former with non-exertional heat strokes.
BACKGROUND: An increase in extreme heat events has been reported along with global warming. Heat exposure in ambient temperature is associated with all-cause diabetes mortality and all-cause hospitalization in diabetic patients. However, the association between heat exposure and hospitalization for hyperglycemic emergencies, such as diabetic ketoacidosis (DKA), hyperosmolar hyperglycemic state (HHS), and hypoglycemia is unclear. The objective of our study is to clarify the impact of heat exposure on the hospitalization for DKA, HHS, and hypoglycemia. METHODS: Data of daily hospitalizations for hyperglycemic emergencies (i.e., DKA or HHS) and hypoglycemia was extracted from a nationwide administrative database in Japan and linked with temperature in each prefecture in Japan during 2012-2019. We applied distributed lag non-linear model to evaluate the non-linear and lagged effects of heat exposure on hospitalization for hyperglycemic emergencies. RESULTS: The pooled relative risk for hyperglycemic emergencies of heat effect (the 90th percentile of temperature with reference to the 75th percentile of temperature) and extreme heat effect (the 99th percentile of temperature with reference to the 75th percentile of temperature) over 0-3 lag days was 1.27 (95 %CI: 1.16-1.39) and 1.64 (95 %CI: 1.38-1.93), respectively. The pooled relative risk for heat effect on hospitalization for hypoglycemia and extreme heat effect over 0-3 lag days was 1.33 (95 %CI: 1.17-1.52) and 1.65 (95 %CI: 1.29-2.10), respectively. These associations were consistent by type of hyperglycemic emergencies and type of diabetes and were generally consistent by regions. DISCUSSION: Heat exposure was associated with hospitalizations for DKA, HHS and hypoglycemia. These results may be useful to guide preventive actions for the risk of fatal hyperglycemic emergencies and hypoglycemia.
BACKGROUND: Climate change, as a defining issue of the current time, is causing severe heat-related illness in the context of extremely hot weather conditions. In Japan, the remarkable temperature increase in summer caused by an urban heat island and climate change has become a threat to public health in recent years. METHODS: This study aimed to determine the potential risk factors for heatstroke by analysing data extracted from the records of emergency transport to the hospital due to heatstroke in Fukuoka City, Japan. In this regard, a negative binomial regression model was used to account for overdispersion in the data. Age-structure analyses of heatstroke patients were also embodied to identify the sub-population of Fukuoka City with the highest susceptibility. RESULTS: The daily maximum temperature and wet-bulb globe temperature (WBGT), along with differences in both the mean temperature and time-weighted temperature from those of the consecutive past days were detected as significant risk factors for heatstroke. Results indicated that there was a positive association between the resulting risk factors and the probability of heatstroke occurrence. The elderly of Fukuoka City aged 70 years or older were found to be the most vulnerable to heatstroke. Most of the aforementioned risk factors also encountered significant and positive associations with the risk of heatstroke occurrence for the group with highest susceptibility. CONCLUSION: These results can provide insights for health professionals and stakeholders in designing their strategies to reduce heatstroke patients and to secure the emergency transport systems in summer.
BACKGROUND: The complex role of urbanisation in heat-mortality risk has not been fully studied. Japan has experienced a rapid population increase and densification in metropolitan areas since the 2000s; we investigated the effects of population concentration in metropolitan areas on heat-mortality risk using nationwide data. METHODS: We collected time-series data for mortality and weather variables for all 47 prefectures in Japan (1980-2015). The prefectures were classified into three sub-areas based on population size: lowest (<1 500 000), intermediate (1 500 000 to 3 000 000), and highest (>3 000 000; i.e. metropolitan areas). Regional indicators associated with the population concentration of metropolitan areas were obtained. RESULTS: Since the 2000s, the population concentration intensified in the metropolitan areas, with the highest heat-mortality risk in prefectures with the highest population. Higher population density and apartment % as well as lower forest area and medical services were associated with higher heat-mortality risk; these associations have generally become stronger since the 2000s. CONCLUSIONS: Population concentration in metropolitan areas intensified interregional disparities in demography, living environments, and medical services in Japan; these disparities were associated with higher heat-mortality risk. Our results can contribute to policies to reduce vulnerability to high temperatures.
This study assesses heatstroke risk in the near future (2031-2050) under RCP8.5 scenario. The developed model is based on a generalized linear model with the number of ambulance transport due to heatstroke (hereafter the patients with heatstroke) as the explained variable and the daily maximum temperature or wet bulb globe temperature (WBGT) as the explanatory variable. With the model based on the daily maximum temperature, we performed the projection of the patients with heatstroke in case of considering only climate change (Case 1); climate change and population dynamics (Case 2); and climate change, population dynamics, and long-term heat acclimatization (Case 3). In Case 2, the number of patients with heatstroke in the near future will be 2.3 times higher than that in the baseline period (1981 – 2000) on average nationwide. The number of future patients with heatstroke in Case 2 is about 10 % larger than that in Case 1 on average nationwide despite population decline. This is due to the increase in the number of elderly people from the baseline period to the near future. However, in 20 prefectures, the number of patients in Case 2 is smaller compared to Case 1. Comparing the results from Cases 1 and 3 reveals that the number of patients with heatstroke could be reduced by about 60 % nationwide by acquiring heat tolerance and changing lifestyles. Notably, given the lifestyle changes represented by the widespread use of air conditioners, the number of patients with heatstroke in the near future will be lower than that of the baseline period in some areas. In other words, lifestyle changes can be an important adaptation to the risk of heatstroke emergency. All of the above results were also confirmed in the prediction model with WBGT as the explanatory variable.
BACKGROUND: Previous studies have reported that high ambient temperature is associated with increased risk of suicide; however, the association has not been extensively investigated with drug overdose which is the most common method of unsuccessful suicidal behavior in Japan. Therefore, this study aims to examine the short-term association between daily mean temperature and the incidence of self-harm attempts by drug overdose in Tokyo, Japan. METHODS: We collected the emergency ambulance dispatch data and daily meteorological data in Tokyo from 2010 to 2014. A quasi-Poisson regression model incorporating a distributed lag non-linear function was applied to estimate the non-linear and delayed association between temperature and drug overdose, adjusting for relative humidity, seasonal and long-term trends, and days of the week. Sex, age and location-specific associations of ambient temperature with drug overdose was also estimated. RESULTS: 12,937 drug overdose cases were recorded during the study period, 73.9% of which were female. We observed a non-linear association between temperature and drug overdose, with the highest risk observed at 21 °C. The highest relative risk (RR) was 1.30 (95% Confidence Interval (CI): 1.10-1.67) compared with the risk at the first percentile of daily mean temperature (2.9 °C) over 0-4 days lag period. In subgroup analyses, the RR of a drug overdose at 21 °C was 1.36 (95% CI: 1.02-1.81) for females and 1.07 (95% CI: 0.66-1.75) for males. Also, we observed that the risk was highest among those aged ≥65 years (RR = 2.54; 95% CI: 0.94-6.90), followed by those aged 15-34 years (RR = 1.25; 95% CI: 0.89-1.77) and those aged 35-64 years (RR = 1.15; 95% CI: 0.78-1.68). There was no evidence for the difference in RRs between urban (23 special wards) and sub-urban areas in Tokyo. CONCLUSIONS: An increase in daily mean temperature was associated with increased drug overdose risk. This study indicated the positive non-linear association between temperature and incomplete attempts by drug overdose. The findings of this study may add further evidence of the association of temperature on suicidal behavior and suggests increasing more research and investigation of other modifying factors.
BACKGROUND: Epidemiological studies based on mortality and crime data have indicated that short-term exposure to higher temperature increases the risk of suicide and violent crimes. However, there are few studies on non-fatal intentional injury, especially on non-fatal self-harm which is much more common than suicide. OBJECTIVES: We aimed to clarify how short-term exposure to temperature is associated with emergency ambulance transport caused by intentional injuries including acts of self-harm and assault. METHOD: We applied a time-stratified case-crossover design using a conditional quasi-Poisson regression model for each of the 46 prefectures. All temperatures were converted to percentile value for each prefecture, to account for the varied climate across Japan. A Distributed Lag Non-Linear Model was used to explore the temperature percentile and lag pattern. The prefecture-specific results were combined using a meta-analysis with the random effects model. RESULT: Between 2012 and 2015, the number of acts of self-harm and assault across all 46 prefectures totaled 151,801 and 95,861, respectively. We found that as the temperature increased, the relative risk (RRs) for both self-harm and assault behaviors increased in a nearly linear manner. The pooled relative risk at the 99th percentile temperature for self-harm behavior was 1.11 (95% CI: 1.07, 1.15) compared with the risk at the 1st percentile temperature, and that for assault was 1.12 (95% CI: 1.08, 1.16) at lag 0. The RRs were highest at lag0 and less than 1 at lag7-20. CONCLUSION: The present study found that short-term exposure to higher temperature promotes the risk of emergency ambulance transport due to acts of self-harm and assault. The lag pattern indicates a possible “displacement” effect. These results suggest that exposure to high temperatures may potentially function as a trigger for intentional injuries.
BACKGROUND: Many studies have investigated the devastating health effects of heat waves, but less is known about health risks related to cold spells, despite evidence that extreme cold may contribute to a larger proportion of deaths. OBJECTIVES: We aimed to systematically investigate the association between cold spells and mortality in Japan. METHODS: Daily data for weather conditions and 12 common causes of death during the 1972-2015 cold seasons (November-March) were obtained from 47 Japanese prefectures. Cold spells were defined as ≥ 2 consecutive days with daily mean temperatures ≤ 5th percentile for the cold season in each prefecture. Quasi-Poisson regression was combined with a distributed lag model to estimate prefecture-specific associations, and pooled associations at the national level were obtained through random-effects meta-analysis. The potential influence of cold spell characteristics (intensity, duration, and timing in season) on associations between cold spells and mortality was examined using a similar two-stage approach. Temporal trends were investigated using a meta-regression model. RESULTS: A total of 18,139,498 deaths were recorded during study period. Mortality was significantly higher during cold spell days vs. other days for all selected causes of death. Mortality due to age-related physical debilitation was more strongly associated with cold spells than with other causes of death. Associations between cold spells and mortality from all causes and several more specific outcomes were stronger for longer and more intense cold spells and for cold spells earlier in the cold season. However, although all outcomes were positively associated with cold spell duration, findings for cold spell intensity and seasonal timing were heterogeneous across the outcomes. Associations between cold spells and mortality due to cerebrovascular disease, cerebral infarction, and age-related physical debility decreased in magnitude over time, whereas temporal trends were relatively flat for all-cause mortality and other outcomes. DISCUSSION: Our findings may have implications for establishing tailored public health strategies to prevent avoidable cold spell-related health consequences. https://doi.org/10.1289/EHP7109.
Japanese encephalitis (JE) is an important mosquito-borne infectious disease in rural areas of Asia that is caused by Japanese encephalitis virus (JEV). Culex tritaeniorhynchus is the major vector of JEV, nevertheless there are other mosquitoes that may be able to transmit JEV. This study confirms that the midgut, head tissue, salivary glands, and reproductive tissue of Aedes albopictus, Armigeres subalbatus, and Culex quinquefasciatus are all able to be infected with JEV after a virus-containing blood meal was ingested by female mosquitoes. Even though the susceptibility to JEV of the different tissues varies, the virus-positive rate increased with the number of days after JEV infection. Moreover, once JEV escapes the midgut barrier, the oral transmission rates of JEV were 16%, 2%, and 21% for Ae. albopictus, Ar. subalbatus, and Cx. quinquefasciatus at 14 days after infection at 30 °C, respectively. There is no supporting evidence to suggest vertical transmission of JEV by the tested mosquitoes. Collectively, raising the temperature enhances JEV replication in the salivary gland of the three mosquito species, suggesting that global warming will enhance mosquito vector competence and that this is likely to lead to an increase in the probability of JEV transmission.
Dengue fever is a leading cause of illness and death in the tropics and subtropics, and the disease has become a threat to many nonendemic countries where the competent vectors such as Aedes albopictus and Aedes aegypti are abundant. The dengue epidemic in Tokyo, 2014, poses the critical importance to accurately model and predict the outbreak risk of dengue fever in nonendemic regions. Using climatological datasets and traveler volumes in Japan, where dengue was not seen for 70 years by 2014, we investigated the outbreak risk of dengue in 47 prefectures, employing the temperature-dependent basic reproduction number and a branching process model. Our results show that the effective reproduction number varies largely by season and by prefecture, and, moreover, the probability of outbreak if an untraced case is imported varies greatly with the calendar time of importation and location of destination. Combining the seasonally varying outbreak risk with time-dependent traveler volume data, the unconditional outbreak risk was calculated, illustrating different outbreak risks between southern coastal areas and northern tourist cities. As the main finding, the large travel volume with nonnegligible risk of outbreak explains the reason why a summer outbreak in Tokyo, 2014, was observed. Prefectures at high risk of future outbreak would be Tokyo again, Kanagawa or Osaka, and highly populated prefectures with large number of travelers.
Few studies have examined the effects of inbound overseas travelers and meteorological conditions on the shift in human respiratory syncytial virus (HRSV) season in Japan. This study aims to test whether the number of inbound overseas travelers and meteorological conditions are associated with the onset week of HRSV epidemic season. The estimation of onset week for 46 prefectures (except for Okinawa prefecture) in Japan for 4-year period (2014-2017) was obtained from previous papers based on the national surveillance data. We obtained data on the yearly number of inbound overseas travelers and meteorological (yearly mean temperature and relative humidity) conditions from Japan National Tourism Organization (JNTO) and Japan Meteorological Agency (JMA), respectively. Multi-level mixed-effects linear regression analysis showed that every 1 person (per 100,000 population) increase in number of overall inbound overseas travelers led to an earlier onset week of HRSV epidemic season in the year by 0.02 week (coefficient -0.02; P<0.01). Higher mean temperature and higher relative humidity were also found to contribute to an earlier onset week by 0.30 week (coefficient -0.30; P<0.05) and 0.18 week (coefficient -0.18; P<0.01), respectively. Additionally, models that included the number of travelers from individual countries (Taiwan, South Korea, and China) except Australia showed that both the number of travelers from each country and meteorological conditions contributed to an earlier onset week. Our analysis showed the earlier onset week of HRSV epidemic season in Japan is associated with increased number of inbound overseas travelers, higher mean temperature, and relative humidity. The impact of international travelers on seasonality of HRSV can be further extended to investigations on the changes of various respiratory infectious diseases especially after the coronavirus disease 2019 (COVID-19) pandemic.
Numerous epidemiological studies have reported that ozone (O(3)) and temperature are independently associated with health outcomes, but modification of the effects of O(3) on health outcomes by temperature, and vice versa, has not been fully described. This study aimed to investigate effect modification by temperature on the association between O(3) and emergency ambulance dispatches (EADs) in Japan. Data on daily air pollutants, ambient temperature, and EADs were obtained from eight Japanese cities from 2007 to 2015. A distributed lag non-linear model combined with Poisson regression was performed with temperature as a confounding factor and effect modifier to estimate the effects of O(3) on EADs at low (<25th percentile), moderate (25th-75th percentile), and high (>75th percentile) temperature for each city. The estimates obtained from each city were pooled by random-effects meta-analysis. When temperature was entered as a confounder, the estimated effects of O(3) on EADs for all acute, cardiovascular, and respiratory illnesses were largest at lag 0 (current-day lag). Therefore, this lag was used to further estimate the effects of O(3) on EADs in each temperature category. The estimated effects of O(3) on EADs for all acute, cardiovascular, and respiratory illnesses in all eight Japanese cities increased with increasing temperature. Specifically, a 10 ppb increase in O(3) was associated with 0.80 % (95 % CI: 0.25 to 1.35), 0.19 % (95 % CI: -0.85 to 1.25), and 1.14 % (95 % CI: -0.01 to 2.31) increases in the risk of EADs for all acute, cardiovascular, and respiratory illnesses, respectively, when city-specific daily temperature exceeded the 75th percentile. Our findings suggest that the association between O(3) and EADs for all acute, cardiovascular, and respiratory illnesses is the highest during high temperature. Finding of this study can be used to develop potential mitigation measures against O(3) exposure in high temperature environment to reduce its associated adverse health effects.
Airborne pollens cause pollinosis and have the potential to affect microphysics in clouds; however, the number of monitored species has been very limited due to technical difficulties for the morphotype identification. In this study, we applied an eDNA approach to the airborne pollen communities in the suburbs of the Tokyo metropolitan area in Japan, within a mixed urban, rural, and mountain landscape, revealing pollen seasonality of various taxa (a total of 78 families across the period) in the spring season (February to May). Those taxa distinctly shifted in the season, especially in the beginning of February and the middle of April. Air temperature shift was an obvious key factor to affect the airborne pollen community, while the influence of other meteorological factors, such as wind speed, humidity, and precipitation, was not clear. Taxonomic classification of major Amplicon Sequence Variants (ASVs) indicates multiple pollen sources, including natural forest, planted forest, roadside, park lands, and horticultural activities. Most major ASV belongs to Japanese cedar (Cryptomeria japonica), which is the most notable allergen that causes pollinosis in Japan, peaking in mid-February to March. Backward trajectory analysis of air masses suggests that the Japanese cedar and other Cupressaceae plantation forests in the western mountains were a significant source of airborne pollen communities detected at our sampling site. Other major plant pollen sources, including Japanese zelkova (Zelkova serrata) and ginkgo (Ginkgo biloba), emanated from the nearby parks or roadside regions. This study’s approach enables us to visualize the phenology of multiple pollen, including timing and duration. Long-term monitoring of this type would provide additional insight into understanding the role of climate change on pollen transmission and links to flowering events.
In Japan, the representative allergenic airborne pollen-related allergic diseases include Cupressaceae in early spring, the birch family and grass in spring and mugwort in autumn. As a result of a long- term survey the past 27 to 33 years, an increasing in the amount of conifer airborne pollen and an earlier start dispersal were observed, related climate change. In addition, an increase in the number of patients with Japanese cedar pollinosis and the severity has been observed. Provision of medical pollen information, medication and sublingual immunotherapy have all been enhanced. Recently, pollen-food allergic syndrome has become of increased interest.
We herein report a 56-year-old woman who developed allergic bronchopulmonary aspergillosis (ABPA) possibly due to fungal exposure after disastrous heavy rainfall in Western Japan in 2018. She was diagnosed with ABPA complicated with asthma, increased peripheral blood eosinophil count, elevation of specific immunoglobulin E for Aspergillus fumigatus, positive Aspergillus fumigatus precipitation antibody reaction test results, and notable chest computed tomography findings. After treatment with benralizumab, her symptoms, peripheral blood eosinophil count, radiological findings, and respiratory function dramatically improved. The administration of benralizumab appears to be an effective treatment strategy for ABPA.
BACKGROUND: Ambient temperature may contribute to seasonality of mortality; in particular, a warming climate is likely to influence the seasonality of mortality. However, few studies have investigated seasonality of mortality under a warming climate. METHODS: Daily mean temperature, daily counts for all-cause, circulatory, and respiratory mortality, and annual data on prefecture-specific characteristics were collected for 47 prefectures in Japan between 1972 and 2015. A quasi-Poisson regression model was used to assess the seasonal variation of mortality with a focus on its amplitude, which was quantified as the ratio of mortality estimates between the peak and trough days (peak-to-trough ratio (PTR)). We quantified the contribution of temperature to seasonality by comparing PTR before and after temperature adjustment. Associations between annual mean temperature and annual estimates of the temperature-unadjusted PTR were examined using multilevel multivariate meta-regression models controlling for prefecture-specific characteristics. RESULTS: The temperature-unadjusted PTRs for all-cause, circulatory, and respiratory mortality were 1.28 (95% confidence interval (CI): 1.27-1.30), 1.53 (95% CI: 1.50-1.55), and 1.46 (95% CI: 1.44-1.48), respectively; adjusting for temperature reduced these PTRs to 1.08 (95% CI: 1.08-1.10), 1.10 (95% CI: 1.08-1.11), and 1.35 (95% CI: 1.32-1.39), respectively. During the period of rising temperature (1.3?°C on average), decreases in the temperature-unadjusted PTRs were observed for all mortality causes except circulatory mortality. For each 1?°C increase in annual mean temperature, the temperature-unadjusted PTR for all-cause, circulatory, and respiratory mortality decreased by 0.98% (95% CI: 0.54-1.42), 1.39% (95% CI: 0.82-1.97), and 0.13% (95% CI: – 1.24 to 1.48), respectively. CONCLUSION: Seasonality of mortality is driven partly by temperature, and its amplitude may be decreasing under a warming climate.
The 2020 summer Olympic and Paralympic Games in Tokyo were postponed to July-September 2021 due to the coronavirus disease 2019 (COVID-19) pandemic. While COVID-19 has emerged as a monumental health threat for mass gathering events, heat illness must be acknowledged as a potentially large health threat for maintaining health services. We examined the number of COVID-19 admissions and the Tokyo rule for emergency medical care, in Tokyo, from March to September 2020, and investigated the weekly number of emergency transportations due to heat illness and weekly averages of the daily maximum Wet Bulb Globe Temperature (WBGT) in Tokyo in the summer (2016-2020). The peak of emergency transportations due to heat illness overlapped the resurgence of COVID-19 in 2020, and an increase of heat illness patients and WBGT has been observed. Respect for robust science is critical for the decision-making process of mass gathering events during the pandemic, and science-based countermeasures and implementations for COVID-19 will be warranted. Without urgent reconsiderations and sufficient countermeasures, the double burden of COVID-19 and heat-related illnesses in Tokyo will overwhelm the healthcare provision system, and maintaining essential health services will be challenging during the 2021 summer Olympic and Paralympic Games.
Recognition of Individual and environmental risks is crucial to alleviate damage inflicted by disasters. In particular, an awareness of floods and their health risks in patients’ residences is important for patients and their healthcare professionals.
Nitrogen dioxide (NO(2)) is an air pollutant discharged from combustion of human activities. Nitrous acid (HONO), measured as NO(2), is thought to impact respiratory function more than NO(2). HONO and NO(2) have an equilibrium relationship, and their reaction is affected by climate conditions. This study was conducted to discuss the extent of HONO contained in NO(2), depending on the level of urbanization. Whether climate conditions that promote HONO production enhanced the level of NO(2) measured was investigated using time series analysis. Climate and outdoor air pollution data measured in April 2009-March 2017 in urban (Tokyo, Osaka, and Aichi) and rural (Yamanashi) areas in Japan were used for the analysis. Air temperature had a trend of negative associations with NO(2), which might indicate the decomposition of HONO in the equilibrium between HONO and NO(2). The associations of relative humidity with NO(2) did not have consistent trends by prefecture: humidity only in Yamanashi was positively associated with NO(2). In high relative humidity conditions, the equilibrium goes towards HONO production, which was observed in Yamanashi, suggesting the proportion of HONO in NO(2) might be low/high in urban/rural areas.
Particulate matter from natural sources such as desert dust causes harmful effects for health. Asian dust (AD) increases the risk of acute myocardial infarction (AMI). However, little is known about the risk of myocardial infarction with nonobstructive coronary arteries (MINOCA), compared to myocardial infarction with coronary artery disease (MI-CAD). Using a time-stratified case-crossover design and conditional logistic regression models, the association between short-term exposure to AD whereby decreased visibility (
BACKGROUND: PM(2·5) is an important but modifiable environmental risk factor, not only for pulmonary diseases and cancers, but for cardiovascular health. However, the evidence regarding the association between air pollution and acute cardiac events, such as out-of-hospital cardiac arrest (OHCA), is inconsistent, especially at concentrations lower than the WHO daily guideline (25 ?g/m(3)). This study aimed to determine the associations between exposure to ambient air pollution and the incidence of OHCA. METHODS: In this nationwide case-crossover study, we linked prospectively collected population-based registry data for OHCA in Japan from Jan 1, 2014, to Dec 31, 2015, with daily PM(2·5), carbon monoxide (CO), nitrogen dioxide (NO(2)), photochemical oxidants (O(x)), and sulphur dioxide (SO(2)) exposure on the day of the arrest (lag 0) or 1-3 days before the arrest (lags 1-3), as well as the moving average across days 0-1 and days 0-3. Daily exposure was calculated by averaging the measurements from all PM(2·5) monitoring stations in the same prefecture. The effect of PM(2·5) on risk of all-cause or cardiac OHCA was estimated using a time-stratified case-crossover design coupled with conditional logistic regression analysis, adjusted for daily temperature and relative humidity. Single-pollutant models were also investigated for the individual gaseous pollutants (CO, NO(2), O(x), and SO(2)), as well as two-pollutant models for PM(2·5) with these gaseous pollutants. Subgroup analyses were done by sex and age. FINDINGS: Over the 2 years, 249?372 OHCAs were identified, with 149?838 (60·1%) presumed of cardiac origin. The median daily PM(2·5) was 11·98 ?g/m(3) (IQR 8·13-17·44). Each 10 ?g/m(3) increase in PM(2·5) was associated with increased risk of all-cause OHCA on the same day (odds ratio [OR] 1·016, 95% CI 1·009-1·023) and at lags of up to 3 days, ranging from OR 1·015 (1·008-1·022) at lag 1 to 1·033 (1·023-1·043) at lag 0-3. Results for cardiac OHCA were similar (ORs ranging from 1·016 [1·007-1·025] at lags 1 and 2 to 1·034 [1·021-1·047] at lag 0-3). Patients older than 65 years were more susceptible to PM(2·5) exposure than younger age groups but no sex differences were identified. CO, O(x), and SO(2) were also positively associated with OHCA while NO(2) was not. However, in two-pollutant models of PM(2·5) and gaseous pollutants, only PM(2·5) (positive association) and NO(2) (negative association) were independently associated with increased risk of OHCA. INTERPRETATION: Short-term exposure to PM(2·5) was associated with an increased risk of OHCA even at relatively low concentrations. Regulatory standards and targets need to incorporate the potential health gains from continual air quality improvement even in locations already meeting WHO standards. FUNDING: None.
OBJECTIVE: It is well known that air temperature is closely related to health outcomes. We investigated the relationship between air temperature parameters and the number of deaths stratified by cause in Gifu prefecture, Japan. METHODS: The number of deaths stratified by cause in Gifu prefecture Japan between January 2007 and December 2016 was obtained from the official homepage of Gifu prefecture, Japan. Air temperature parameters (?), i.e., the mean air temperature, mean of the highest air temperature, mean of the lowest air temperature, the highest air temperature, and the lowest air temperature during the same period in Gifu city were also obtained from the Japan Meteorological Agency official home page. The relationship between air temperature parameters and the number of deaths was evaluated in an ecological study. RESULTS: The number of deaths due to heart disease, cerebrovascular disease, pneumonia, accidents, or renal failure in January (coldest winter season in Japan) was the highest among the months. Simple correlation analysis also demonstrated a significant and negative relationship between air temperature parameters and the number of deaths due to heart disease, cerebrovascular disease, senility, pneumonia, accidents, and renal failure. CONCLUSION: Lower air temperature may be associated with a higher number of deaths due to diseases in Gifu prefecture, Japan.
It has been reported that suicide is associated with ambient temperature; however, the heterogeneity in this association and its underlying factors have not been extensively investigated. Therefore, we investigated the spatial and temporal variation in the temperature-suicide association and examined climatic, demographic, and socioeconomic factors that may underlie such heterogeneity. We analyzed the daily time-series data for the suicide counts and ambient temperature, which were collected for the 47 prefectures of Japan from 1972 to 2015, using a two-stage analysis. In the first stage, the prefecture-specific temperature-suicide association was estimated by using a generalized linear model. In the second stage, the prefecture-specific associations were pooled, and key factors explaining the spatial and temporal variation were identified by using mixed effects meta-regression. Results showed that there is an inverted J-shape nonlinear association between temperature and suicide; the suicide risk increased with temperature but leveled off above 24.4 °C. The nationwide relative risk (RR) for the maximum suicide temperature versus 5th temperature percentile (2.9 °C) was estimated as 1.26 (95% CI: 1.22, 1.29). The RRs were larger for females than for males (1.32 vs. 1.22) and larger for elderly people (?65 y) than for the non-elderly (15-64 y) (1.51 vs. 1.18). The RRs were larger for rural prefectures, which are characterized by smaller population, higher proportions of females and elderly people, and lower levels of financial capability and the proportion of highly educated people. The RRs were also larger in colder and less humid prefectures. These findings may help in understanding the potential mechanism of the temperature-suicide association and projecting the future risk of suicide under climate change.
Many studies have reported effects of global climate change on wildlife, including changes in species distributions and population sizes but perspectives on interactions between the biosphere and the anthroposphere are limited. Bears have a worldwide range and often come into conflict with humans. We assessed the effects of weather variables including temperature, precipitation, and sunshine on human-bear conflicts. Given that the relationship between climate and bear physiology is poorly understood, we first conducted an exploratory analysis using regression techniques. We then built a final predictive model using generalized linear mixed modelling and Akaike’s Information Criterion (AIC)-based model selection. Our model highlighted the influence of cold temperatures during denning on the frequency of human-bear conflicts. Cold temperatures during denning are related to increased energy requirements for thermoregulation. It is likely that the resulting increase in demand for food following denning leads to an increase in human-bear conflicts. Our results also indicate that cool springs, lingering winter snowpacks, and hot summers may increase human-bear conflicts due to associated reductions in key food sources.
Southwestern Japan suffered its worst rains in 2018 causing floods and mudslides, claiming 225 lives and forcing millions for evacuations. Referred as “Heisei san-j?-nenshichi-gatsug?u”, the disaster was the result of incessant precipitation caused by the interaction of typhoon “Prapiroon” with the seasonal rain front “Baiu”. The present epidemiological study aims to investigate disaster-induced health issues in 728 residents of Innoshima island in the Hiroshima Prefecture by comparing their clinical data in pre-disaster (2017) and disaster-hit (2018) years which was obtained from annual health screening. Comparison of data showed a significant increase in the urine protein concentration in victims following the disaster. Probing further into the household conditions, showed that a total of 59,844 households were affected with water outage during the heavy rains, which was accompanied by severe damage of sewerage pipelines with complete recovery process taking two weeks. This two weeks of the crisis forced victims to refrain from using restrooms which in turn led to infrequent urination, thereby explaining the increased urine protein concentration in victims following the disaster. The present study addresses the acute health implications caused by the water crisis and serves as a precautionary measure for disaster management council to provide enhanced aftercare services in victims in further events of natural disasters.
The WHO Housing and health guidelines recommend a minimum indoor temperature of 18°C to prevent cold-related diseases. In Japan, indoor temperatures appear lower than in Euro-American countries because of low insulation standards and use of partial intermittent heating. This study investigated the actual status of indoor temperatures in Japan and the common characteristics of residents who live in cold homes. We conducted a nationwide real-world survey on indoor temperature for 2 weeks in winter. Cross-sectional analyses involving 2190 houses showed that average living room, changing room, and bedroom temperatures were 16.8°C, 13.0°C, and 12.8°C, respectively. Comparison of average living room temperature between prefectures revealed a maximum difference of 6.7°C (Hokkaido: 19.8°C, Kagawa: 13.1°C). Compared to the high-income group, the odds ratio for living room temperature falling below 18°C was 1.38 (95% CI: 1.04-1.84) and 2.07 (95% CI: 1.28-3.33) for the middle- and low-income groups. The odds ratio was 1.96 (95% CI: 1.19-3.22) for single-person households, compared to households living with housemates. Furthermore, lower room temperature was correlated with local heating device use and a larger amount of clothes. These results will be useful in the development of prevention strategies for residents who live in cold homes.
Measures to mitigate climate change are being considered all over the world. Reducing the use of air conditioners is one such measure. While it seems to be effective in mitigating climate change, it may also reduce individuals’ well-being and increase the risk of heatstroke. To compare the impact of reducing air conditioner use and the mortality risks, the indicator Loss of Happy Life Expectancy (LHpLE), which measures the reduction in the length of life that individuals can spend happily, was used. The reduction in well-being due to non-use of air conditioners was obtained by applying the propensity score matching method to the results of a questionnaire. We evaluated the impact of reducing air conditioner use in both the current and future situation in comparison to the mortality risk from flood and heatstroke, respectively. The increase in mortality risk due to flooding was estimated based on numerical simulation, and the increase in the risk of mortality due to heatstroke was estimated based on existing reports in Japan. Using these results, the magnitude of the impacts on LHpLE caused by the reduction in well-being due to the non-use of an air conditioner and the increase in the mortality risks were compared, both for the current situation and the future. The results show that LHpLE due to non-use of air conditioners was much greater than that due to the risk of mortality due to flood and heatstroke, and implied that reducing air conditioner use is not necessarily a good way as a mitigation measure. This result would be useful for creating and implementing measures to counter climate change and could also be applied in many other fields.
