This study aimed to clarify the degree of utilization of off-campus and club activity instructors in high school club activities and examined its association with coaches’ health status. All club activity coaches, mostly teacher, at Japanese high schools were included. The survey items included the following: school (area, establishment, and number of students), club (type, number and sex of athletes, activity status, and aim), and coach (sex, age, teaching license, teaching career, marital status, smoking, drinking, exercise, medical history, subjective health status, K6 scale, and utilization of off-campus and club activity instructors). The proportion of utilization of off-campus and club activity instructors were analyzed. The odds ratios (ORs) of utilization of off-campus instructors and club activity instructors for good subjective health status were calculated. In addition, the ORs for a good K6 score was determined. A total of 7,892 coaches responded. Of these, 22.0% utilized off-campus instructors and 7.4% utilized club activity instructors. In athletic clubs, coaches who used off-campus instructors demonstrated superior health outcomes. Among culture clubs, the ORs were not significant. However, among athletic clubs, the ORs (95% confidence interval) of utilization of off-campus instructors for subjective health status (good/bad) and the K6 score (13-20 points/0-4 poinst) were 0.74 (0.55-0.98) and 1.68 (1.19-2.37), respectively. Longitudinal studies are needed in the future.

The hazards of self-heating substances are generally measured under a constant airflow rate or natural convection. However, chemical materials are used under a wide range of airflow conditions. An increase of airflow rate around a chemical material is indicative of an increase in the supply of reactants, such as oxygen gas, which increases the risk of self-ignition. However, an excessive air supply may exhibit a cooling effect and reduce the risk of self-ignition. The underestimation or overestimation of these hazards can occur when the effects of the airflow rate are not fully considered.

In this study, the effect of airflow on the self-ignition temperature was assessed using isothermal Grewer oven test and activated carbon as the model material. The tests showed that the self-ignition temperature of activated carbon decreased owing to an increase in the oxygen supply with an increase in the airflow rate, while a significant increase in the airflow rate resulted in an increase of self-ignition temperature owing to cooling with air. These results indicate that the isothermal Grewer oven test under a variable gas flow rate can be used to estimate the risk of underestimating or overestimating hazards owing to gas flow.

In recent years, reducing long working hours through objective methods of working time monitoring has been promoted. However, some studies have indicated a discrepancy between self-reported working hours and company-recorded working hours. This study aimed to examine the current methods of working time monitoring in the workplace. Additionally, the relationships between industry type, number of employees, and overtime work were analyzed. A survey cooperation request was sent to the safety and health managers of 35,000 randomly selected workplaces, and data from 3,587 responses were included in the analysis. Results indicated that approximately 70% of workplaces utilize timecards or IC cards for monitoring working hours, while 20% do not utilize any objective method. Additionally, the “manufacturing” and “wholesale and retail trade” industries tended to utilize objective methods more frequently. Furthermore, workplaces with a smaller number of employees were less likely to utilize objective methods, and those utilizing objective methods were less likely to report long working hours. Based on these findings, there is a need to reveal the current methods of working time monitoring in the workplace and its impact.

Stiff neck and shoulder (Katakori) is a health problem with the largest loss of Japanese labor productivity. This study examined the effectiveness of “anma massage shiatsu therapy by Health-keeper,” for this problem.

Perticipants with “Katakori” and perceived decreased labor productivity were randomly assigned to either the active intervention group (receiving intervention at least once a week), the usual intervention group (receiving intervention at the participant’s convenience), or a no-treatment control group. The intervention was the anma-acupressure therapy of about 20 minutes per time, and health-keepers with the license of the anma/massage/shiatsu were carried out. The primary endpoint was the change in the amount of labor productivity loss due to “Katakori” before and after the 3-month follow-up period.

The amount of change in labor productivity loss was -3,065 yen in the usual intervention group (n=9) and -33,565 yen in the active intervention group (n=13), compared to +36,170 yen in the control group (n=10).

These results indicate that instructing office workers who are aware of the loss of labor productivity due to stiff shoulders to receive anma shiatsu therapy with health-keepers for about 20 minutes per session at least once a week may significantly reduce the amount of labor productivity loss compared to the untreated control.

Among accidents resulting in death, injury, or disease in the workplace that results in absence of four days or more, approximately 800 were caused by hazardous substances. The analysis results caused by “contact with substances, etc.” have been published by the Ministry of Health, Labor and Welfare, but the analysis results for “other types of accidents by substances” have not been published and the actual situation is unknown. So, investigations and analyses are conducted for “other types of accidents by substances”. From 2020 to 2022, there were approximately 400 accidents for these types per year, and more than 80% of these were burns. Looking at the occurrence of burn by type of work, the most common burns occur in cooking-related work, followed by venting gas from spray cans, etc. Approximately 70% of the cases occurred at businesses with fewer than 50 workers. Based on the analysis of accidents, examples of disaster prevention measures are suggested.