Introduction: Carpal tunnel syndrome (CTS) is prevalent in workers who utilize hand-held vibration tools, engage in tasks involving repetitive wrist movements, and suffer from wrist overuse. Although electrical injuries involving the median nerve are a relatively rare but plausible cause of CTS, the related literature is limited. Here, we report a case of CTS in which the symptoms developed after an electrical injury, and review the related literature.
Case summary: The patient was a right-handed male electrician who often used hand tools but had no symptoms of CTS before the injury, with the left hand as the point of entry. Typical symptoms of CTS manifested after the electrical injury, and a nerve conduction velocity test confirmed the presence of severe CTS in the left hand. Therefore, we believe that the symptoms can be largely attributed to the electrical injury.
Conclusions: The available literature supports the occurrence of delayed compressive neuropathy caused by scarring from substantial cutaneous burns in patients with electrical injuries. This case shows that electrical injuries may cause CTS in the absence of severe scarring through other mechanisms such as direct injuries to the nerve. Therefore, patients with electrical burns should be routinely examined for peripheral nerve compression symptoms in follow-ups, even when there are minimal cutaneous burns.
Objectives: Fitness is essential to specialist police forces, who have higher occupational demands than general police, and vital to performance and mission success. However, little research has been done profiling the metabolic fitness of these units and how they compare to other populations. The objective of this study was to profile the aerobic fitness of a specialist police unit.
Methods: Body weight was measured to account for any impact on metabolic fitness, while VO2 max was estimated via number of shuttles completed on the 20m Progressive Shuttle Run Test (PSRT) (n=47) on two dates one calendar year apart.
Results: There were no significant (p=.116) differences (mean difference 0.40±1.70kg) in body weight between the initial measures (mean=88.84±8.25kg) and the final measure (mean=89.24±8.77kg) 13 months later. PSRT results increased significantly (p<.005) between the initial (mean=72.62±11.76 shuttles) and final assessments (77.51±11.46 shuttles), with a mean increase of 4.89 (± 2.94) shuttles and a small effect size (d=0.42). The mean VO2 max of the specialist police unit was 51.06±3.61 ml/min/kg following the first assessment, and 52.56±3.46 ml/min/kg following the second assessment. This was a significant finding (p<.001), with a mean difference of 1.19±1.27 ml/min/kg and a small effect size (d=0.23).
Conclusions: Elite police forces have a higher metabolic fitness than the general population and general duties police officers. Having and maintaining this fitness level is imperative for their operational success and preventing injuries. This research suggests that despite the challenges posed by operational requirements, high fitness standards can not only be maintained, but also improved.
This Document, "Guidelines for personal exposure monitoring of chemicals" ("this Guideline"), has been prepared by "The Committee for Personal Exposure Monitoring" ("the Committee") of the Expert Division of Occupational Hygiene & Ergonomics, Japan Society for Occupational Health. Considering the background of the growing importance of personal exposure monitoring in risk assessment and the need to prepare for the introduction of monitoring using personal samplers from an administrative perspective in recent years, the Committee was organized in November 2012. The Committee has prepared this Guideline as a "practical guideline" for personal exposure monitoring, so as to offer proposals and recommendations to the members of the Japan Society for Occupational Health and to society in general. The scope of this Guideline covers all chemical substances and all related workplaces regarded as targets for general assessment and the management of risk. It thus is not to be considered to comment on legal regulations and methodology. The main text provides the basic methods and concepts of personal exposure monitoring, while 31 "Appendices" are provided in this Guideline throughout the series; technical descriptions, statistical bases, and actual workplace examples are provided in these appendices, to assist better understanding. The personal exposure monitoring described as per this Guideline is equivalent to an "expert-centered basic method to reasonably proceed with the assessment and management of risk at workplaces." It is considered that practicing and expanding on this method will significantly contribute in reforming the overall framework of occupational hygiene management in Japan.
Objective: The differences in the methodologies of various occupational health risk assessment (OHRA) models have not been extensively reported. We aimed to understand the qualitative and quantitative differences between common OHRA models in typical industries.
Methods: The Environmental Protection Agency (EPA), Australian, Romanian, Singaporean, International Council on Mining and Metals (ICMM), and the Control of Substances Hazardous to Health (COSHH) models were evaluated, and a theoretical framework was established for a comparative study.
Results: Qualitative comparisons showed that each OHRA model had its own strengths and limitations, and exhibited a diverse distribution at different levels for each evaluation indicator. The Singaporean, COSHH, and EPA models had a much higher comprehensive advantage than the other models for all indicators. Quantitative comparisons demonstrated that these three models also had a stronger ability to distinguish the difference in risk ratios between different industries. The Singaporean model had the strongest correlation with the other models.
Conclusion: Each model possessed its own strengths and limitations depending on its unique methodological principles. Combining the EPA, Singaporean, and COSHH models might be advantageous for developing an OHRA strategy. More studies comparing multiple models in key industries are required.
Background:ortho-Toluidine (OT) was listed as a Group 1 carcinogen by the International Agency for Research on Cancer in 2012 based on epidemiological observations of workers co-exposed to OT and aromatic amines. From 2014 to 2017, several cases of bladder cancer (BCa) secondary to occupational exposure, primarily to OT, were detected in Japan.
Objective: To describe 10 cases of BCa in male Japanese workers exposed primarily to OT at two plants that produce organic dye and pigment intermediates.
Methods: Details of the 10 cases were obtained from company records and through a questionnaire and interview. The surrogate level of exposure to each aromatic amine was calculated as the total job-weight/month for each process for each job-year.
Results: No quantitative exposure data were available. In most cases the surrogate level of exposure to OT was higher than to other amines. All 10 cases were exposed primarily to OT and co-exposed to para-toluidine, ortho-anisidine, aniline, 2,4-xylidine or ortho-chloroaniline. The age range at diagnosis was 41–71 years (mean 56). The duration of OT exposure was 7–28 years (mean 16.5). Disease latency was 16–28 years (mean 21.9). Eight patients were smokers. The main symptom at diagnosis was hematuria (70%).
Conclusions: The characteristics of BCa cases were associated with a high surrogate level of OT exposure and a disease latency of more than 20 years from the initial OT exposure. The main route of OT exposure was likely through the skin. It is necessary to continue health examinations in these target groups.
Objectives: This study aimed to investigate the association between occupational clusters and allergic rhinitis (AR).
Methods: The study was based on data from the Korean National Health and Nutrition Examination Survey (KNHANES: 2007-2015). This study included 46,965 individuals: 20,491 men and 26,474 women. AR was defined as having been diagnosed by a physician. Occupations were classified according to occupational characteristics and skill levels into white (chief executives, senior officials, legislators, managers, professionals, and technicians), pink (clerks, clerical support workers, services and sales workers), blue (craft and related trades workers, drivers, plant and machine operators, assemblers, elementary occupation workers), and green (skilled agricultural, forestry, and fishery workers) categories. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) of AR according to the occupational clusters by using the chi-squared test and logistic regression. Results: In the study population, 10.7% of the men and 13.5% of the women had AR. The prevalence of AR was highest among white-collar workers, followed by pink, blue, and green-collar workers. Compared to green-collar workers, among men the adjusted ORs of the blue, pink, and white-collar workers were 2.00 (95% CI 1.58–2.53), 2.46 (95% CI 1.91–3.15), and 2.78 (95% CI 2.20–3.51), respectively; and among women were 2.45 (95% CI 1.99–3.02), 2.64 (95% CI 2.15–3.25), and 3.63 (95% CI 2.96–4.47), respectively.
Conclusions: This study suggests that AR prevalence is significantly associated with occupational clusters.
Objectives: This study was conducted to: 1) describe sleep duration, fatigue, daytime sleepiness, and occupational errors among Thai nurses and 2) explore the influence of sleep duration on fatigue, daytime sleepiness, and occupational errors.
Methods: A cross-sectional design was implemented. A convenience sample of 233 full-time nurses with at least one year of work experience was recruited to participate in the study. Data were collected using self-reported questionnaires and 1-week sleep diaries. Descriptive and logistic regression statistics were performed using SPSS software.
Results: The mean total sleep time was 6.2 hours. Of the total participants, 75.9% (n=167) experienced short sleep duration, 38.2% (n=84) experienced fatigue, and 49.5% (n=109) experienced excessive daytime sleepiness. Occupational errors were reported by 11.7% (n=25). Medication errors, incorrectly performed procedures, and needle stick injuries were reported by 6.5% (n=13), 5.6% (n=12), and 4.7% (n=10), respectively, of participants performing the associated activities. The "Short Sleep Duration" group experienced more fatigue (p=.044) and excessive daytime sleepiness (p=.001) compared with the "Adequate Sleep Duration" group. Although occupational errors were more common in the "Short Sleep Duration" group, the difference between the two groups did not reach the level of statistical significance. Multivariable logistic regression analysis found that short sleep duration was a statistically significant risk factor for excessive daytime sleepiness (OR=2.47, 95% CI=1.18-5.19).
Conclusions: The majority of registered nurses experience short sleep duration. Short sleep duration increased the risk of excessive daytime sleepiness but not fatigue or occupational errors. Adequate night-time sleep is paramount for preventing daytime sleepiness and achieving optimal work performance.
Objective: One effective strategy for management of musculoskeletal disorders is self-management based on the biopsychosocial model. Self-management requires patients to have adequate health literacy, defined as the individual's ability to seek, understand, and utilize health information. Recently, the neck pain-specific health behavior for office workers (NHBOW) questionnaire was developed based upon a conceptual framework of health literacy. The content in the NHBOW relates to the work and exercise behaviors of office workers. The primary aim of this study was to evaluate the predictive validity of the NHBOW.
Methods: At baseline, 342 healthy participants filled out a series of questionnaires, including the NHBOW. The incidence of neck pain was prospectively recorded every month over a 12-month period. Sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristics curve (AUC) were calculated.
Results: There were 103 (30.7%) incidents of non-specific neck pain among 335 office workers during the 12-month period, and seven participants were lost to follow-up. For the NHBOW, a cut-off score of less than or equal to 8 points (lower scores indicate poorer health behavior) had a sensitivity of 57.3% and a specificity of 96.6%. The positive and negative predictive values were 88.1% and 83.6%, respectively. The AUC was 0.769 (95% CI: 0.706 to 0.832).
Conclusion: The NHBOW was an acceptable screening tool for predicting non-specific neck pain in office workers during the 1-year follow-up period, and can be used in occupational and primary care settings.
Objectives: This retrospective cohort study evaluated the impact of the Stress Check Program, a recently introduced national policy and program aimed at reducing psychological distress among Japanese workers.
Methods: A baseline survey was conducted from November 2015 to February 2016, the period when Japan began enforcing the Stress Check Program. A one-year follow-up survey was conducted in December 2016. In the follow-up survey, two exposure variables were collected: having taken the annual stress survey, and experiencing an improvement in the psychosocial work environment. Psychological distress was assessed using the Brief Job Stress Questionnaire (BJSQ) at baseline and 1-year follow-up. The two exposure variables were used to define four groups: "Neither", "Stress survey (SS) only", "Psychosocial work environment improvement (WI) only", and "Both". BJSQ results were analyzed using repeated measures general linear modeling (GLM).
Results: The study included 2,492 participants: 1,342 in the "Neither" group, 1,009 in the "SS only" group, 76 in the "WI only" group, and 65 in the "Both" group. Overall time-group interaction effects were not significant. The "Both" group showed significantly greater improvements in psychological distress than the "Neither" group (p = 0.02) at the 1-year follow-up, although the effect size was small (d = -0.14).
Conclusions: Combination of the annual stress survey and improvement in psychosocial work environment may have been effective in reducing psychological distress in workers, although the effect size was small.
Objectives: Rotating shift work has been reported to increase the risk of cardiovascular diseases. Vascular endothelial dysfunction and platelet activation are among the leading causes of thrombus formation in patients with myocardial infarction or stroke. Endothelial function has been shown to be impaired immediately after night-shift work; however, it is not known whether platelets are also activated. The aim of this study was to investigate the acute impact of night-shift work on platelet function.
Methods: This observational study included 11 healthy medical staff members (seven women, median age 32 years). We examined each subject's platelet aggregation rates and the serum concentrations of eicosanoid mediators after night-shift work and on day-shift work without preceding night-shift work (baseline).
Results: Platelet aggregation did not differ from baseline levels after night-shift work. However, serum cyclooxygenase (COX)-metabolized eicosanoid mediators, particularly thromboxane (Tx) B2 (a stable metabolite of TxA2 and the most important marker of platelet activation), were significantly higher after the night-shift than at baseline (median 65.3 vs 180.4 ng/ml).
Conclusions: Although platelet aggregation did not increase, there was an increase in serum COX-metabolized eicosanoid mediators such as TxB2 in healthy medical staff after night-shift work. This platelet hypersensitivity may be one of the mechanisms underlying the significant association between night-shift work and adverse cardiovascular outcomes.
Objectives: To evaluate the effects of a 2-month lifestyle intervention for dry eye disease in office workers.
Methods: Prospective interventional study (randomized controlled study). Forty-one middle-aged Japanese office workers (men, 22; women, 19; 39.2 ± 8.0 years) with definite and probable dry eye disease were enrolled and randomized to an intervention group (n = 22) and a control group (n = 19). The intervention aimed at modifying diet, increasing physical activity, and encouraging positive thinking. The primary outcome was change in dry eye disease diagnoses. Secondary outcome was change in disease parameters, including dry eye symptoms, as assessed using the Dry Eye-Related Quality of Life Score, corneal and conjunctival staining scores, tear break-up time, and Schirmer test results.
Results: A total of 36 participants (intervention group, 17; control group, 19) completed the study. The number of definite dry eye disease diagnoses decreased from four to none (p =.05), and the dry eye symptom score showed a significant decrease in the intervention group (p =.03). In contrast, the corneal and conjunctival staining scores, tear break-up time, and Schirmer test results did not differ significantly between groups.
Conclusions: The 2-month lifestyle intervention employed in this study improved dry eye disease status among office workers, with a considerable decrease in subjective symptoms. Lifestyle intervention may be a promising management option for dry eye disease, although further investigation of long-term effects are required.
Objective: In this study, an experiment was conducted to examine whether noise exposure produced acute changes in cardiovascular responses, and whether these responses differed based on psycho-acoustic parameters to noises of low to high intensity. Methods: Thirty healthy subjects were enrolled. Three industrial noises were binaurally presented with a supra-aural earphone. The sound levels of noise were <55, 75, and 90 dB. Each noise was continued for 20 min and the electrocardiogram was simultaneously recorded. Results: The results showed a statistically significant increase in systolic blood pressure (SBP) at the 90 dB sound level. The study estimated a blood pressure increase of 0.85 mmHg/10 dB and 0.71 mmHg/10 dB in SBP and diastolic blood pressure (DBP), respectively. These results suggest that exposure to noise, particularly high-frequency noise, negatively impacts blood pressure. The tonality and fluctuation strength of noise especially impacts systolic blood pressure. Conclusions: The psycho-acoustic parameters of noise should be considered when evaluating the impact of noise exposure.
Background: It has been difficult to make reliable hazard assessments of manufactured nanomaterials, because the nanomaterials form large agglomerations in both in vitro and in vivo studies. Objective: A project by the New Energy and Industrial Technology Development Organization (NEDO) of Japan has succeeded in ensuring the stability of dispersion (nanoscale <100 nm) of manufactured nanomaterials, and is developing hazard assessments of manufactured nanomaterials. Results and Conclusion: Focusing on titanium dioxide, fullerenes and carbon nanotubes, we introduce findings made in inhalation and intratracheal installation studies overseas, and together with the findings made in the NEDO project, and also assess the hazards presented by manufactured nanoparticles.