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Background: The impact of COVID-19 infection on workers' work function persists even after the acute phase of the infection. We studied this phenomenon in Japanese workers. Methods: We conducted a one-year prospective cohort study online, starting with a baseline survey in December 2020. We tracked workers without baseline work functioning impairment and incorporated data from 14,421 eligible individuals into the analysis. We estimated the incidence rate ratio for new onset of work functioning impairment due to COVID-19 infection during follow-up, using mixed-effects Poisson regression analysis with robust variance. Results: Participants reporting infection between January and December 2021 showed a significantly higher incidence of new work functioning impairment (adjusted incidence rate ratio: 2.18, 95% confidence interval: 1.75–2.71, p

Background and Objectives: Limited research has focused on the relationship between cancer, job loss, and factors associated with job loss among older workers. Therefore, in this study, we aimed to examine the relationship between cancer and intention to leave and between physical-health-related issues, mental-health-related issues, and cancer-related symptoms and intention to leave among older workers with cancer. Materials and Methods: This cross-sectional internet-based study included 4498 workers aged 60–75 years. Intention to leave was assessed based on whether individuals considered quitting their current jobs in the near future. Results: A multivariate logistic regression analysis showed a significant association between cancer and intention to leave (adjusted odds ratio [aOR]: 1.42, 95% confidence interval [CI]: 1.01–2.00, p = 0.045). In addition, physical-health-related issues (aOR: 2.33, 95% CI: 1.10–4.92, p = 0.026) and mental-health-related issues (aOR: 4.44, 95% CI: 1.80–10.98, p = 0.001) were significantly associated with the intention to leave. Conclusions: Healthcare providers and employers must address the physical- and mental-health-related issues facing older workers with cancer to help them secure their employment.

ObjectiveVaccine hesitancy is a major issue for acquiring herd immunity. However, some individuals may go unvaccinated owing to inhibitory factors other than vaccine hesitancy. If there is even a small number of such people, support is needed for equitable vaccine distribution and acquiring herd immunity. We investigated sociodemographic factors that affected not undergoing COVID-19 vaccination in Japan among individuals who had strong intention to vaccinate before beginning the vaccination.MethodsWe conducted this prospective cohort study on workers aged 20–65 years from December 2020 (baseline), to December 2021 using a self-administered questionnaire survey. There were 27,036 participants at baseline and 18,560 at follow-up. We included 6,955 participants who answered yes to this question at baseline: “Would you like to receive a COVID-19 vaccine as soon as it becomes available?” We applied multilevel logistic regression analyses to examine the association between sociodemographic factors and being unvaccinated at follow-up.ResultsIn all, 289 participants (4.2%) went unvaccinated. The odds ratios (ORs) for being unvaccinated were significantly higher for participants aged 30–39 and 40–49 than those aged 60–65 years. Being divorced, widowed, or single, having low income, and having COVID-19 infection experience also had higher ORs.DiscussionWe found that some participants who initially had strong intention to vaccinate may have gone unvaccinated owing to vaccine side effects and the financial impact of absenteeism due to side effects. It is necessary to provide information repeatedly about the need for vaccination as well as social support to ensure that those who intend to vaccinate are able to do so when aiming for acquiring herd immunity through vaccination against COVID-19 as well as other potential infection pandemics in the future.

ABSTRACTObjectives The work style reforms and the coronavirus disease pandemic in Japan have prompted efforts toward teleworking, mainly work from home (WFH). This study aimed to prospectively evaluate the impact of WFH on job stress among Japanese workers.Methods This online survey-based prospective cohort study was conducted from December 2020 (baseline) to December 2021 (1-year follow-up) using self-administered questionnaires. At baseline, 27,036 participants completed the questionnaires, whereas 18,560 (68.7%) participated in the 1-year follow-up. After excluding the 11,604 participants who left or changed workplaces within 1 year or who were physical laborers and hospitality workers, data from 6,956 participants were analyzed. We asked participants about WFH frequency at baseline and conducted a follow-up using the Brief Job Stress Questionnaire (BJSQ). Participants were divided into four groups according to WFH frequency. The odds ratios of poor states of the association of the four subscales (job demand, job control, supervisor support, and coworker support) determined by the BJSQ with WFH frequency were estimated using a multilevel logistic model.Results In both the gender–age adjusted and multivariate models, compared to the non-WFH group, the medium and low WFH groups were less likely to have poor job control, whereas the high WFH group were likely to have similar levels as the non-WFH group. In both models, compared to non-WFH participants, the high WFH group were more likely to have poor supervisor and coworker support.Conclusions High-frequency WFH requires further attention, because it may increase job stress by exacerbating deficits of social support in the workplace. Medium- and low-frequency WFH workers were more likely to have satisfactory job control; therefore, limiting WFH to three or fewer days per week may lead to better job stress management.

Objectives: This study examined the relationship of potential advisors — human resources or services that advise workers when they experience health issues that affect their work and work-related health — with psychological distress and analyzed which human resources have a greater impact on improving workers’ mental health. Methods: An Internet-based survey using a self-administered questionnaire was conducted. The target population was workers between the ages of 20 and 69 years. Among a total of 5,111 participants, 4,540 were included in the present analysis. Participants were asked questions regarding potential advisors on work-related health issues. The Kessler 6-item Psychological Distress Scale (K6) was used to assess psychological distress. We used a generalized linear model with a binomial response for assessing the relationship between K6 scores and each potential advisor on work-related health issues. Results: Participants without potential advisors on work-related health issues were significantly more likely to score both K6 ≥5 (cutoff for mild psychological distress) and K6 ≥13 (cutoff for severe psychological distress) than the participants with potential advisors (all p

Abstract Background To prevent the spread of coronavirus disease (COVID-19), it is important to avoid 3Cs (closed spaces, crowded places, and close-contact settings). However, the risk of contact with an unspecified number of people is inevitable while commuting to and from work. In this study, we investigated the relationship between commuting, and the risk of COVID-19 and COVID-19-induced anxiety. Methods An internet-based questionnaire survey was conducted to obtain a dataset from 27,036 respondents. One-way commuting time was evaluated using a five-case method. The commuting distance was estimated using zip codes of the home and workplace. Logistic regression analysis was performed with the following outcomes: COVID-19 risk, close contact, infection anxiety, and infection anxiety due to commuting. Commuting distance and commuting time were analyzed separately in the model. We excluded participants with incalculable commuting distance, commuting distance exceeding 300 km, commuting distance of 0 km, or who telecommuted at least once a week. Results The total number of participants included in the analysis was 14,038. The adjusted odds ratios (aORs) of using public transportation for severe acute respiratory syndrome coronavirus 2 infection were 4.17 (95% confidence interval [CI]: 2.51–6.93) (commuting time) and 5.18 (95% CI: 3.06–8.78) (commuting distance). The aOR of COVID-19 diagnosis decreased significantly with increasing commuting distance. The aORs of using public transportation to infection anxiety were 1.44 (95% CI: 1.31–1.59) (commuting time) and 1.45 (95% CI: 1.32–1.60) (commuting distance). The longer the commuting time, the more the aOR increased. Conclusions COVID-19 risk, close contact, and infection anxiety were all associated with the use of public transportation during commuting. Both commuting distance and time were associated with infection anxiety due to commuting, and the strength of the association increased with increase in commuting time distance. Since transportation by commuting is associated with COVID-19 risk and anxiety, we recommend the use of telecommuting and other means of work.

Background: There are increasing concerns that prevention measures against coronavirus disease 2019 (COVID-19) such as social distancing and telework are leading to loneliness and poor lifestyle habits like increased alcohol consumption. The purpose of this study was to assess whether loneliness reported among workers during the COVID-19 pandemic is associated with changes in alcohol consumption. Methods: The study comprised a cross-sectional, online survey of 27,036 workers between December 22 and 26, 2020. A questionnaire was used to assess loneliness, usual alcohol consumption and whether that consumption had changed. Odds ratios (ORs) were estimated by logistic regression analysis. Results: A total of 2831 (10.5%) workers indicated they had increased alcohol consumption during the pandemic. Increased alcohol consumption was significantly associated with loneliness (OR = 1.94, 95%CI 1.70–2.21). This association held true for those who indicated they drank two or more days per week (OR = 1.98 95%CI 1.71–2.30) and those who drank less than one day per week (OR = 1.51 95%CI 0.71–3.25). In contrast, there was no association between increased alcohol consumption and loneliness among those who indicated they hardly ever drank (OR = 1.22 95%CI 0.55–2.72). Conclusions: Among those drinking more than once a week, increased alcohol consumption is associated with loneliness.

BackgroundThe COVID-19 pandemic has dramatically transformed the work environment and practices worldwide. Long-term infection control practices may increase the psychological distress of workers, and, conversely, inadequate infection control practices in the working place may increase the fear of infection. This study aimed to determine the relationship between infection control practices in the working place and employee mental state during the COVID-19 pandemic in Japan.MethodsThis study was conducted in December 2020 and February 2021. The participants had undergone a preliminary survey, which revealed that they were in a good mental state. Their psychological distress was investigated via a second survey, and the factors associated with distress were studied using a logistic model.ResultsThe results of the second survey indicated that 15.3% of participants demonstrated psychological distress. This was associated with leave-of-absence instructions, instructions for shortening business hours, and requests to avoid the working place in case of any symptoms.ConclusionThe study found that while some infection control practices reduce workers' distress, others worsen it. Employers need to consider infection control practices as well as the worsening mental state of employees following a decrease in income caused by such measures. Follow-up studies may be necessary to clarify the long-term effects on workers' mental states.

BackgroundOwing to the impact of the COVID-19 pandemic, work environments and systems, as well as occupational health measures or activities that fall within our research field, are constantly changing. It is necessary to assess the impact of these changes on the physical and mental health of workers. ObjectiveTo assess how occupational health measures affect the health of workers, we conducted a baseline, longitudinal internet-based survey among Japanese workers in October 2021 and additionally scheduled 2 follow-up surveys for 2022 and 2023. We describe the details of the protocol of the work systems and health internet research (WSHIR) study, provide an overview of the results of the baseline survey, and discuss the study procedures and data used in the study. MethodsThis prospective cohort study was conducted online among internet monitors. The baseline survey was conducted from October 1 to 7, 2021. This study targeted those who were working and between the ages of 20 and 69 years. A total of 5111 respondents who passed the screening survey and proceeded to the main survey were enrolled according to collection units organized by sex and age. For the screening and main surveys, the questionnaire consisted of 9 and 33 items with 9 and 55 questions, respectively. Consistency and completeness checks were performed after the questionnaires were submitted. We compared basic characteristics, such as sex, age group, educational background, and marital status, among all participants, including those who withdrew from the analysis. ResultsOf the 5111 initial survey respondents, 571 (11.2%) were considered fraudulent. The data of the remaining 4540 (88.8%) participants (2273, 50.1%, males; 2267, 49.9%, females) included in the analysis were well balanced across participant sex and age groups according to the sampling plan because there was no significant difference by sex and age group using the chi-square test for checking the distribution bias of the participants (P=.84). Compared to female participants, male participants tended to be more likely to be managers and supervisors (323, 14.2%, males; 86, 3.8%, females), to work in a secondary industry (742, 32.6%, males; 357, 15.7%, females), and to have an annual income of ≥5 million yen (976, 42.9%, males; 429, 18.9%, females). For the evaluation of a psychological indicator, Kessler 6 (K6) score, by sex and age group, the characteristics of the score distribution of the included participants were similar to those reported in previous studies. ConclusionsThis study presents a protocol and overview of the results of an internet-based occupational health survey of workers. Using the results of this survey, we hope to evaluate the changes in occupational health activities and their impact on workers' health while controlling for the COVID-19 pandemic.

BackgroundThe COVID-19 pandemic has resulted in treatment interruption for chronic diseases. The scale of COVID-19 in Japan has varied greatly in terms of the scale of infection and the speed of spread depending on the region. This study aimed to examine the relationship between local infection level and treatment interruption among Japanese workers.MethodsCross-sectional internet survey was conducted from December 22 to 26, 2020. Of 33,302 participants, 9,510 (5,392 males and 4,118 females) who responded that they required regular treatment were included in the analysis. The infection level in each participant's prefecture of residence was assessed based on the incidence rate (per 1,000 population) and the number of people infected. Age-sex and multivariate adjusted odds ratios (ORs) of regional infection levels associated with treatment interruption were estimated by multilevel logistic models, nested by prefecture of residence. The multivariate model was adjusted for sex, age, marital status, equivalent household income, educational level, occupation, self-rated health status and anxiety.ResultsThe ORs of treatment interruption for the lowest and highest levels of infection in the region were 1.32 [95 % confidence interval (CI) were 1.09–1.59] for the overall morbidity rate (per 1,000) and 1.34 (95 % CI 1.10–1.63) for the overall number of people infected. Higher local infection levels were linked to a greater number of workers experiencing treatment interruption.ConclusionsHigher local infection levels were linked to more workers experiencing treatment interruption. Our results suggest that apart from individual characteristics such as socioeconomic and health status, treatment interruption during the pandemic is also subject to contextual effects related to regional infection levels. Preventing community spread of COVID-19 may thus protect individuals from indirect effects of the pandemic, such as treatment interruption.

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has been linked to a rise in loneliness. Loneliness is associated with sleep-related problems, which in turn can be a risk factor for various psychiatric disorders. However, it is unclear whether loneliness is linked to sleep-related problems during the pandemic. Here, we studied the association between loneliness and sleep-related problems during the COVID-19 pandemic in Japan.MethodsA total of 33,302 individuals who indicated they were employed were surveyed online. The survey responses of 27,036 participants were analyzed. Odds ratios (ORs) were estimated using univariate and multiple logistic regression analyses.ResultsOf those analyzed, 2,750 (10.2%) experienced feelings of loneliness. Further, sleep-related problems were significantly more common among those who felt lonely both in the short term (more than 3 days) and the long term (more than 3 months). The ORs were much weaker after adjusting for factors related to interpersonal connections, such as family and friendships, than after adjusting for factors related to socioeconomic status.ConclusionLoneliness may be a risk factor for sleep-related problems in the COVID-19 pandemic. Having connections with family and friends may have a moderating effect on the occurrence of sleep-related problems.

Abstract Background Exposure to toner, a substance used in photocopiers and printers, has been associated with siderosilicosis and other adverse effects. However, these findings are limited, and there is insufficient evidence on the long-term effects of toner exposure. Using longitudinal analysis, this study aimed to examine the effects of work involving toner exposure on the respiratory system over time. Methods We conducted a prospective cohort study in a Japanese toner and copier manufacturing enterprise between 2003 and 2013. The cohort included a total of 1468 workers, which comprised 887 toner-handling workers and 581 non-toner-handling workers. We subdivided the toner-handling workers into two groups according to the toner exposure concentration, based on the baseline survey in 2003. We compared the chest X-ray results, respiratory function indicators, and serum and urinary biomarkers of inflammation, allergy, and oxidative stress among the three groups: high-concentration toner exposure group, low-concentration toner exposure group, and non-toner-handling group. To consider the effects of individual differences on the longitudinal data, we used a linear mixed model. Results Similar chest X-ray results, the biomarkers, and most of the respiratory function indicators were found in the non-toner-handling and toner-handling groups. There were no significant yearly changes in the percentage of vital capacity (%VC) in the high-concentration toner exposure group, while there was a significant yearly increase in %VC in the low-concentration toner exposure group and non-toner-handling group. The yearly change in each group was as follows: high-concentration toner exposure group, − 0.11% (95% confidence interval [CI], − 0.29 to 0.08; P = 0.250); low-concentration toner exposure group, 0.13% (95% CI, 0.09–0.17; P

BackgroundStudies have determined that exercise and physical activity positively affect physical and mental health, and that healthy workers contribute to increased work performance. The relationship between the time spent on exercise during leisure time and physical activity, including work, with health-related quality of life (HRQOL) in workers is unclear, with variations observed between occupational types. This cross-sectional study examined these associations among Japanese workers from various occupations during the COVID-19 pandemic.MethodsAn Internet-based national health survey—Collaborative Online Research on Novel-coronavirus and Work-study (CORoNaWork study)—was conducted among 33,087 Japanese workers in December 2020. After excluding invalid responses, 27,036 participants were categorized into four and five groups according to exercise and physical activity time, respectively. Each group's scores were compared on each of the four questions on the Japanese version of the Centers for Disease Control and Prevention Health-Related Quality of Life (CDC HRQOL-4) using generalized linear models. Age-sex adjusted and multivariate models were used to compare each index of the CDC HRQOL-4.ResultsCompared to the reference category (almost never), any level of exercise (ORs 0.56–0.77) and physical activity (ORs 0.93–0.88) were associated with better self-rated health in the multivariate model. Any exercise was also associated with significantly reduced odds for physically or mentally unhealthy days; however, high levels of physical activity (≥120 min/day) were associated with significantly increased odds for these outcomes (ORs = 1.11 and 1.16, respectively).ConclusionsThe results suggest that exercise habits are more critical to workers' HRQOL than physical activity. Interventions that encourage daily exercise even for a short time are likely to be associated with better workers' health and work performance.

In dust-generating scenarios in occupational environments, it is important to take measures to prevent not only pneumoconiosis, but also heatstroke. The aim of this study was to verify whether using a tight-fitting half-facepiece breath-response powered air-purifying respirator (PAPR) in combination with a self-produced cooling device could abate the deep body temperature while performing activities. We conducted a crossover study involving 10 subjects. The subjects were subjected to three conditions: wearing a PAPR equipped with a cooling device, PAPR, or a replaceable particulate respirator. During the experiment, the rectal temperature of the subjects was measured, along with the temperature near the PAPR inlet in container with the cooling device when the PAPR equipped with the cooling device was worn. The subjects rested in a cold chamber set at a dry-bulb temperature of 28°C and relative humidity of 45% for 20 min. Then, they moved to a hot chamber set to a dry-bulb temperature of 36°C (with the same relative humidity) in 5 min and exercised on a cycle ergometer for 30 min. After that, the subjects moved to the cold chamber for 5 min and rested for 20 min. Notably, the air inhaled by the subjects wearing PAPR equipped with the cooling device was approximately 10°C cooler than the ambient air. Furthermore, 35 min after the initiation of the experiment (after the middle of the exercise period), the rectal temperature of the participants wearing the PAPR equipped with the cooling device was lower than of those wearing PAPR or replaceable particulate respirators (p

The purpose of this study was to examine the association between loneliness and psychological distress during the COVID-19 pandemic in Japan. We conducted a cross-sectional online study from 22 to 26 December 2020. A total of 27,036 participants, all employed at the time, were included in the analysis. Participants were asked if they felt loneliness in a single-item question. The Kessler 6 (K6) was used to assess psychological distress, defined as mild for K6 scores of 5 to 12 and severe for 13 or higher. The odds ratios (ORs) of psychological distress associated with loneliness were estimated using a multilevel logistic model nested in the prefecture of residence, with adjustment for age, sex, marital status, equivalent income, educational level, smoking, alcohol consumption, job type, number of workplace employees, and cumulative incidence rate of COVID-19 in the prefecture. Communication with friends, acquaintances, and family was strongly associated with psychological distress, so we adjusted for these factors and eating meals alone. Results showed a significant association between loneliness and psychological distress (OR = 36.62, 95% CI = 32.95–40.69). Lack of friends to talk to, lack of acquaintances to ask for help, and lack of people to communicate with through social networking sites were all strongly associated with psychological distress, as were family time and solitary eating. Even after adjusting for these factors, loneliness remained strongly associated with psychological distress (OR = 29.36, 95% CI = 26.44–32.98). The association between loneliness during the COVID-19 pandemic and psychological distress indicates the need for intervention.

A cohort study spanning ten years was conducted to assess the health effects on toner manufacturing workers. A survey consisting of questions investigating subjective respiratory symptoms, current medical history, disease occurrence, dust exposure concentrations at the workplace, respiratory function tests, biochemical and immunological items in blood and urine, and a chest radiograph or chest computed tomography survey was conducted. The results of these surveys have been published in academic journals, and none of the surveys showed any findings suggesting significant health problems in the toner-worker group compared to the non-toner-worker group. The results suggest that the health risks associated with toner handling are not high when the work environment at the toner handling site is well controlled.

Objectives: The aim of this study was to clarify the current status of respiratory protection and associated problems among workers engaged in dust-generating work, including the type of respiratory protective equipment (RPE) used, methods for wearing RPE, and awareness of respiratory protection. Methods: We surveyed 212 male workers involved in dust-generating work from 10 plants on the current status and problems associated with respiratory protection. The survey inquired about work environment, type of RPE used, methods for wearing RPE, and knowledge of respiratory protection. Questions about methods for wearing RPE inquired about the position of the headband and placement of something like fabric between the face-piece cushion and face when wearing RPE. Analyses were performed using simple tabulation of each question item. Results: A total of 53.3% of RPE used by participants were replaceable filter dust masks and 19.3% were disposable dust masks. Of the workers who regularly used replaceable filter RPE, 50.0% wore the headband around the helmet. Meanwhile, 27.4% placed a knit cover between the face-piece cushion and their faces, and 11.0% used a towel instead of a knit cover. A total of 69.5% of workers who placed fabric between the face-piece cushion and their face perceived that “there was no problem with respiratory protection”. Conclusion: We found that workers engaged in dust-generating work used a variety of methods for wearing RPE. Workers should be provided with appropriate education on respiratory protection and instruction on appropriate methods for wearing RPE in the workplace.

Objectives: Although musculoskeletal pain is considered to be a major contributor to chronic pain in Japan, there are few epidemiological studies on chronic musculoskeletal pain in workers. Presenteeism, defined as attendance at work in spite of the need to rest due to poor health, related to chronic pain causes a decrease in labor productivity, and its economic loss is said to be four times greater than that of Absenteeism. In this study, we examined the relationship between the actual state of musculoskeletal pain in workers and chronic musculoskeletal pain and labor productivity, with the goal of obtaining useful information to improve labor productivity. Methods: A questionnaire was distributed to 3,406 workers, of whom 2,055 were analyzed to determine the prevalence of chronic musculoskeletal pain and the affected body parts, and the influence of work-related factors and the degree of labor productivity loss due to chronic musculoskeletal pain. Results: 34.0% of subjects had chronic musculoskeletal pain. The most commonly reported pain site was “neck and shoulder”. Chronic musculoskeletal pain was significantly more common in people working overtime and in physical workers. Labor productivity was significantly lower in the group with chronic musculoskeletal pain than in the group without musculoskeletal pain, and it was significantly lower in the “neck and shoulder” and “lower back” groups than in the group without chronic musculoskeletal pain. Conclusions: Thirty-four percent of workers were engaged in work while experiencing chronic musculoskeletal pain. These workers had significantly decreased labor productivity. Efforts to improve conditions for workers with chronic musculoskeletal pain in each work type and working condition may improve labor productivity.

Objectives This report shows the relationship between toner exposure and respiratory effects for individuals with a longterm occupational toner-handling history, from 2004 to 2013. Material and Methods Authors studied 752 Japanese male workers in toner handling workshops. A total of 673 men who participated in an annual monitoring survey were analyzed in this study. The following monitoring was performed in the same season each year: personal exposure measurements, biological markers, respiratory function tests, a chest X-ray, chronic respiratory symptoms and incidences of respiratory diseases. To evaluate the toner exposure effect, the exposure categories suitable for each evaluation index were established. Results For those with an occupational toner-handling history, the mean occupational toner-handling period was 14.36 years (standard deviation = 6.62); one participant had 35 years of exposure, which was the longest and one participant had 1 year of exposure which was the shortest. There were no statistically significant differences in the rate of change of respiratory function tests. An ANOVA conducted on blood and urine test results showed that statistically significantly differences were observed for a few items but all the values were very low and within the standard range. Conclusions Authors conducted a 10-year ongoing study, but no obvious negative influences on health were attributed to toner exposure. In a work environment where adequate administrative controls are in place, personal toner exposure levels may be expected to be low, with no adverse effects on human health. Int J Occup Med Environ Health 2018;31(6):809–822

Monitoring of personal exposure to hazardous substances has garnered increasing attention over the past few years. However, no straightforward and exact indoor positioning technique has been available until the recent discovery of Wi-Fi round trip time (Wi-Fi RTT). In this study, we investigated the possibility of using a combination of Wi-Fi RTT for indoor positioning and a wearable particle monitor (WPM) to observe dust concentration during walking in a simulated factory. Ultrasonic humidifiers were used to spray sodium chloride solution inside the factory. The measurements were recorded three times on different routes (Experiments A, B, and C). The error percentages, i.e., measurements that were outside the expected measurement area, were 7% (49 s/700 s) in Experiment A, 2.3% (15 s/660 s) in Experiment B, and 7.8% (50 s/645 s) in Experiment C. The dust measurements were also recorded without any obstruction. A heat map was created based on the results from both measured values. Wi-Fi RTT proved useful for computing the indoor position with high accuracy, suggesting the applicability of the proposed methodology for occupational health monitoring.

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Background: Focusing on the respiratory function for health effect indices, we conducted a cross-sectional study on workers who did and did not handle toner to compare the longitudinal changes. Methods: Among 116 individuals who worked for a Japanese business equipment manufacturer and participated in the study, the analysis included 69 male workers who we were able to follow up for 4 years. We categorized the 40 workers engaged in toner-handling work as the exposed group and the 29 workers not engaged in these tasks as the referent group, and compared their respiratory function test results: peak expiratory flow rate (PEFR), vital capacity (VC), predicted vital capacity (%VC), forced expiratory volume in 1 second (FEV1), and forced expiratory volume in 1 second as a percent of forced vital capacity (FEV1%). Results: The cross-sectional study of the respiratory function test results at the baseline and at the 5th year showed no statistically significant differences in PEFR, VC, %VC, FEV1, and FEV1% between the exposed and referent workers. Also, respiratory function time-course for 4 years was calculated and compared between the groups. No statistically significant differences were shown. Conclusion: Our study does not suggest any toner exposure effects on respiratory function. However, the number of subjects was small in our study; studies of larger populations will be desired in the future.

The purpose of this study was to examine the effects of toner-handling work on respiratory symptoms and diseases. We conducted a prospective cohort study of 1468 workers between 2003 and 2013. The cohort included 887 toner-handling workers and 581 non-toner-handling workers, employed in one toner and copier manufacturing enterprise. Toner-handling workers were subdivided into two groups based on the 8-h time-weighted average toner exposure concentration for each work category in the baseline survey. We compared the incidence of respiratory disease and longitudinal changes in the prevalence of subjective respiratory symptoms among three groups, as follows: High-concentration toner exposure group, the low-concentration toner exposure group, and a control group. The incidence of respiratory disease and changes in the prevalence of subjective respiratory symptoms were similar between the non-toner-handling group and the toner-handling group. In contrast, the odds ratio for yearly changes in the prevalence of wheezing without asthmatic response was significantly lower in the high-concentration toner exposure group than in the control group. At the study site, dust scattering was well controlled and workers used respiratory protection appropriately. These findings suggest that toner-handling work had little adverse effect on respiratory function in a work environment with sufficiently controlled ventilation.

Background Cigarette smoking is one of the major factors that increases arterial stiffness. The purpose of this study was to examine further the relationship between smoking status and arterial stiffness using a new index, the cardio-ankle vascular index (CAVI), in male Japanese workers. Methods This cross-sectional study included 4,729 male Japanese workers undergoing annual health checkups. CAVI was measured at the time of the annual health checkup between April 2007 and March 2008. The subjects were divided into three groups, smokers (n = 1,913), former smokers (n = 1,481) and non-smokers (n = 1,348) according to their responses to a questionnaire. We compared the CAVI in the three groups after adjusting for age. Multiple regression analysis was used to examine the association between CAVI and the number of cigarettes smoked per day in order to examine whether there was a dose–response relationship between smoking and CAVI. Results The mean CAVI for each group was 7.81 ± 0.02 for smokers, 7.70 ± 0.02 for former smokers and 7.64 ± 0.02 for non-smokers. A significant difference was observed between each group. According to the results of multiple regression analysis, the standardized β of the number of cigarettes smoked per day was 0.09 (p < 0.01). This confirmed a positive association with CAVI. Conclusions Our study demonstrated that there is a significant association between the number of cigarettes smoked per day and arterial stiffness, as measured by CAVI.

Understanding the effects of lifestyle and radiation on health is important for the health management of disaster recovery workers. International research has demonstrated the relationship between natural disasters and diseases. The lifestyle and working conditions following the Great East Japan Earthquake potentially increased the incidence of cardiovascular disease and obesity among affected individuals. The aim of this study was to analyze the body mass index (BMI) of 1,341 emergency workers who responded to the accident at the Fukushima Daiichi Nuclear Power Plant. The BMI of each emergency worker was measured immediately after the accident and compared with that measured at the initial survey conducted 5 yr later to determine the effect of lifestyle habits on BMI. Awareness of the frequency of eating out and caloric intake helped maintain their BMI, while evacuation contributed to the increase in BMI. Prevention of obesity, which can trigger or exacerbate certain health conditions, such as heat exhaustion, infection, and cerebrocardiovascular disease, requires diet counseling, with a focus on maintaining adequate caloric intake; moreover, special consideration should be provided to evacuated workers. [ABSTRACT FROM AUTHOR]

This study evaluated the differences in respiratory protection between replaceable particulate respirators (RPRs) and powered air-purifying respirators (PAPRs) based on different wearing methods during exercise tasks. Ten participants wore RPRs and PAPRs alternately in ways comparable to those adopted by workers in actual workplaces. We measured the fit factor of the respiratory protective equipment (RPE) during exercise tasks for each wearing variation. The exercise load was set to 80W using an ergometer. The exercise tasks comprised five actions described in the Japan Industrial Standard T8150 in 2018. We compared the results with experimental data obtained at rest in our previous studies. The fit factor of RPRs during exercise was significantly lower than (p<0.001) and about half that measured at rest, indicating inadequate respiratory protection. On the other hand, the fit factor of PAPRs during exercise tasks was also significantly lower than (p<0.001) and about half that at rest, but respiratory protection was maintained. This suggests that the protection provided by PAPRs is independent of wearing method during exercise. PAPRs may thus be better than RPRs for workers who have to wear RPE inappropriately due to health problems. [ABSTRACT FROM AUTHOR]

There is a drive to support workers in Japan undergoing medical treatment who wish to continue working, known as the work–treatment balance. This support for the work–treatment balance is expected to boost their mental health. This study examines the relationship among the work–treatment balance, job stress, and work engagement. This study was conducted in December 2020 in Japan, with 27,036 participants. We divided the participants into three groups by the receipt state of support for work–treatment balance: control group (do not need support), unsupported group, and supported group. The scores on the parameters of the job content questionnaire and the Utrecht Work Engagement Scale (UWES-3) were compared among groups using a multilevel regression with age-sex or multivariate-adjusted models. In the two models, the job control score of the unsupported group was significantly lower than that of the control group. The two social support scores of the supported group were significantly higher than those of the control group. The scores on the UWES-3 of the unsupported group were significantly lower than those of the control group. The support of work–treatment balance for workers could have a positive impact on their mental health. [ABSTRACT FROM AUTHOR]

This study evaluated the performance of two respirators, a replaceable particulate respirator (RPR) and a powered air-purifying respirator (PAPR), worn according to non-recommended methods. Ten subjects wore either an RPR or PAPR according to the recommended method, or according to a non-recommended method, with a knit cover placed between the facepiece cushion and face, with a towel placed between the facepiece cushion and face, or with the headband on a helmet. The leakage rate of each wearing variation was then measured, according to the procedure for determining the protection factor of respiratory protective equipment, using atmospheric dust as required by JIS T8150. The average leakage rate for the RPR was 1.82-10.92%, whereas that of the PAPR was 0.18-0.42%. The performance of the RPR decreased when worn in methods outside of recommendations; however, there was no significant decrease in the performance of PAPR under any method of wear. Therefore, a PAPR is recommended for work in which a replaceable or disposable particulate respirator fails to provide sufficient protection against hazardous dust substances, or for workers who are unable to use a particulate respirator according to the recommended method owing to the work environment or health conditions. [ABSTRACT FROM AUTHOR]

This study examines the acute and chronic respiratory effects of toner exposure based on markers for interstitial pneumonia, oxidative stress and pulmonary function tests. A total of 112 subjects working in a Japanese toner and photocopier manufacturing company participated in this study in 2004. We annually conducted personal exposure measurements, pulmonary function tests, chest X - ray examinations, biomarkers, and questionnaires on respiratory symptoms to the subjects. We report in this paper the results of the analysis of combined annual survey point data from 2004 to 2008 and data from three annual survey points, 2004, 2008, and 2013. During these survey periods, we observed that none of subjects had a new onset of respiratory disease or died of such a disease. In both the analyses, there were no significant differences in each biomarker and pulmonary function tests within the subjects, nor between a toner -- handling group and a non - toner -- handling group, except for a few results on pulmonary function tests. The findings of this study suggest that there were no acute and chronic respiratory effects of toner exposure in this cohort group, although the number of subjects was small and the level of toner exposure in this worksite was low. [ABSTRACT FROM AUTHOR]

This study examines the relationship between toner-handling work and its health effects on self-reported respiratory symptoms. The subjects were 1,504 male workers in a Japanese toner and photocopier manufacturing company. Personal exposure measurement, pulmonary function tests, chest X-ray examination, measurement of biomarkers, and a questionnaire about self-reported respiratory symptoms were performed annually. This study discusses the questionnaire results. We found that the toner-handling group showed significantly higher prevalence of breathlessness than the never-toner-handling group. The significant reduction of pulmonary function and fibrosis change in the chest X-ray examination associated with breathlessness were not observed. However the morbidity of asthma was higher compared to the Japanese population in both of the toner-handling group and the never-toner handling group, the effect of toner exposure was not clarified. Nevertheless, while the toner exposure levels in the current well controlled working environment may be sufficiently low to prevent adverse health effects, further studies are needed to assess the more long-term latent health effects of toner exposure. [ABSTRACT FROM AUTHOR]

Previous studies have shown that immature polymorphonuclear leukocytes (PMNs) newly released from the bone marrow on pulmonary inflammation may preferentially sequester in the lung and cause endothelial damage in the lung microvessels, which may contribute to the observed decrease in lung function. The aim of this study was to determine changes in PMN release from the bone marrow induced by crystalline silica. Japanese white rabbits were exposed to crystalline silica (Min-U silica, 50 mg) (n = 6) intratracheally. The systemic inflammatory response was measured as changes in circulating 5Œ-bromo-2-deoxyuridine (BrdU)-positive PMN (PMNBrdU) newly released from the bone marrow. Silica exposure caused a shortening transit time of PMN through the bone marrow, especially in their last division in the mitotic pool, than in the control (P < 0.02). A BAL study 48 h after instillation of crystalline silica showed that the number of PMN and PMNBrdU recovered by lavage was significantly greater than from the control (P < 0.05). We conclude that, as with other inflammatory sources such as cigarette smoking, ambient particulate matter or pneumococcal pneumonia, crystalline silica instillation into the lung induces immature PMN from bone marrow and may contribute to the observed pulmonary lesion. [ABSTRACT FROM AUTHOR]