Amid the effects of global warming, Tokyo has become an increasingly hot city, especially during the summertime. To prepare for the upcoming 2020 Summer Olympics and Paralympics in Tokyo, all participants, including the athletes, staff, and spectators, will need to familiarize themselves with Tokyo’s hot and humid summer conditions. This paper uses the wet-bulb globe temperature (WBGT) index, which estimates the risk of heat illness, to compare climate conditions of sports events in Tokyo with the conditions of the past three Summer Olympics (held in Rio de Janeiro, London, and Beijing) and to subsequently detail the need for establishing appropriate countermeasures. We compared WBGT results from the past three Summer Olympics with the same time periods in Tokyo during 2016. There was almost no time zone where a low risk of heat illness could be expected during the time frame of the upcoming 2020 Tokyo Olympics. We also found that Tokyo had a higher WBGT than any of those previous host cities and is poorly suited for outdoor sporting events. Combined efforts by the official organizers, government, various related organizations, and the participants will be necessary to deal with these challenging conditions and to allow athletes to perform their best, as well as to prevent heat illnesses among staff and spectators. The sporting committees, as well as the Olympic organizing committee, should consider WBGT measurements in determining the venues and timing of the events to better avoid heat illness and facilitate maximum athletic performance.

Carbamazepine (CBZ) is the most frequent culprit drug for severe cutaneous adverse drug reactions (ADR), such as Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and drug‐induced hypersensitivity syndrome (DIHS). A strong association between human leukocyte antigen (HLA)‐B*1502 and CBZ‐induced SJS/TEN has been reported in Han Chinese, Thai, Malaysian and Indian populations, but not in Caucasian or Japanese populations. Recent studies showed an association between HLA‐A*3101 and CBZ‐induced ADR in Caucasian and Japanese populations. We conducted a case–control study to determine HLA genotyping of patients with CBZ‐induced ADR in a Japanese population. Fifteen patients with CBZ‐induced ADR and 33 subjects who had taken CBZ for more than 3 months without evidence of any ADR as a control were enrolled. In addition, the results of a CBZ‐induced lymphocyte stimulation test were compared between the groups. A strong association was found between HLA‐A31 and CBZ‐induced ADR (P < 0.001), and a weak association was found between HLA‐A11 and HLA‐B51 with CBZ‐induced ADR. No HLA‐B*1502 was found in either patients or control subjects. The mean CBZ‐induced lymphocyte stimulation index was significantly high in patients with CBZ‐induced ADR compared with CBZ‐tolerant patients (P < 0.001); however, no significant difference was seen between HLA‐A31‐positive subjects and HLA‐A31‐negative subjects in either group. These findings suggest that HLA‐A31 is strongly associated with CBZ‐induced ADR in the Japanese, but does not determine CBZ‐induced lymphocyte proliferation.

Heat-related illness (HRI) is a common occupational injury, especially in construction workers. To explore the factors related to HRI risk in construction workers under hot outdoor working conditions, we surveyed vital and environmental data of construction workers in the summer season. Sixty-one workers joined the study and the total number of days when their vital data during working hours and environmental data were recorded was 1165. Heart rate with high-risk HRI was determined using the following formula: 180 − 0.65 × age. As a result of the logistic regression analysis, age, working area, maximum skin temperature, and heart rate immediately after warming up were significantly positively related, and experience of construction was significantly negatively related to heart rate with high-risk HRI. Heart rate immediately after warming up may indicate morning fatigue due to reasons such as insufficient sleep, too much alcohol intake the night before, and sickness. Asking morning conditions may lead to the prevention of HRI. For occupational risk management, monitoring of environmental and personal conditions is required.

The present study was a cross-sectional study conducted to reveal the prevalence of metabolic syndrome and its components and describe the features of such prevalence among Japanese workers by clustered business category using big data. The data of approximately 120,000 workers were obtained from a national representative insurance organization, and the study analyzed the health checkup and questionnaire results according to the field of business of each subject. Abnormalities found during the checkups such as excessive waist circumference, hypertension or glucose intolerance, and metabolic syndrome, were recorded. All subjects were classified by business field into 18 categories based on The North American Industry Classification System. Based on the criteria of the Japanese Committee for the Diagnostic Criteria of Metabolic Syndrome, the standardized prevalence ratio (SPR) of metabolic syndrome and its components by business category was calculated, and the 95% confidence interval of the SPR was computed. Hierarchical cluster analysis was then performed based on the SPR of metabolic syndrome components, and the 18 business categories were classified into three clusters for both males and females. The following business categories were at significantly high risk of metabolic syndrome: among males, Construction, Transportation, Professional Services, and Cooperative Association; and among females, Health Care and Cooperative Association. The results of the cluster analysis indicated one cluster for each gender with a higher prevalence of metabolic syndrome components; among males, a cluster consisting of Manufacturing, Transportation, Finance, and Cooperative Association, and among females, a cluster consisting of Mining, Transportation, Finance, Accommodation, and Cooperative Association. These findings reveal that, when providing health guidance and support regarding metabolic syndrome, consideration must be given to its components and the variety of its prevalence rates by business category and gender.

Risk and preventive factors for heat illness in radiation decontamination workers after the Fukushima Daiichi Nuclear Power Plant accident: Takeyasu Kakamu, et al. Department of Hygiene and Preventive Medicine, Fukushima Medical University School of MedicineObjective: The aim of this study was to reveal factors related to heat illness in radiation decontamination workers and determine effective preventive measures.Methods: A self‐administered questionnaire was sent to 1,505 radiation decontamination workers. The questionnaire included age, sex, duration of decontamination work, previous occupation, education provided by employers regarding heat illness, preventive action against heat illness, and subjective symptoms of heat illness during work. We included 528 men, who replied and answered all questions, in the statistical analysis. Subjective symptoms of heat illness were categorized as “no symptoms”, “Grade I” and “Grade II” according to severity. A multiple linear regression model was used to determine the factors associated with the severity of heat illness.Results: The mean age of the subjects was 47.6 years old (standard deviation: 13.4). Of the 528 workers, 316 (59.8%) experienced heat illness symptoms (213 at Grade I and 103 at Grade II). The results of the stepwise selection revealed that age, outdoor manual labor, adequate sleep, use of a cool vest, and salt intake were selected as preventive factors, whereas living in a company dormitory or temporary housing, wearing light clothing, and consuming breakfast were selected as risk factors for heat illness.Conclusions: Both working conditions and living environment are associated with heat illness in radiation decontamination workers. Type of housing and sleep are also strongly related to heat illness during work. Employers should consider not only the working conditions of the employee but also the employee's daily living conditions, in order to prevent heat illness.

Aim: Polypharmacy in elderly people is a social issue and has been reported to cause not only drug adverse events, but also falls, dysfunction and cognitive decline. Those events may trigger prolonged length of hospitalization. Therefore, the aim of this study was to investigate whether polypharmacy has a prolonging effect on hospitalization.Methods: The study subjects were 584 patients in a university hospital in Japan who had been admitted for hepatectomy, pancreaticoduodenectomy, gastrectomy or colectomy, and to whom clinical pathways had been applied. In this study, polypharmacy was defined as taking five or more regular oral medications, and prolonged hospitalization was defined as hospitalization longer than that determined by the clinical pathway. Multiple logistic regression analysis was performed to investigate whether polypharmacy affects the length of hospitalization.Results: The subjects were 348 males and 236 females, mean ± SD age of 65.8 ± 12.9 years. Among all subjects, 228 (39.0%) were receiving polypharmacy at admission, and the number of patients with prolonged hospitalization was 262 (44.9%). Multiple logistic regression analysis revealed that the following variables were significantly associated with prolonged hospitalization; polypharmacy (odds ratio = 1.532; 95% confidence interval = 1.010–2.327), age 50–59; 2.971 (1.216–7.7758), age 60–69; 2.405 (1.059–5.909), organ pancreas; 0.298 (0.122–0.708), operation time ≥386 min; 2.050 (1.233–3.432), intraoperative bleeding volume ≥401 mL; 2.440 (1.489–4.038), postoperative delirium; 2.395 (1.240–4.734), postoperative infection; 10.715 (4.270–33.059).Conclusion: The current study revealed that polypharmacy at admission was an independent factor for prolonged hospitalization. In future, measures against polypharmacy are required, collaborating with outpatient clinics, family doctors and dispensing pharmacies. Geriatr Gerontol Int 2020; 20: 1085–1090..