Objectives: Prolonged sitting with a flexed back and neck is recognized as being associated with an increased risk of neck and back pain disorders among overhead crane operators. The aim of this study was to compare back and head postures over a full shift of work between operators who experience back and neck pain, and healthy operators. Methods: In a first phase, the prevalence of musculoskeletal symptoms was assessed using the Nordic questionnaire among 120 crane operators. Based on first phase results, 17 operators with back/neck disorders were matched with 15 healthy operators based on age and selected to participate in the second phase of the study. Postures and movements were continuously measured over an 8 h shift using inclinometers. Results: The highest 12-month prevalence of musculoskeletal disorders was found in the lower back, neck and knees. Case and control groups differed significantly in back and head flexion angles at the 50th percentiles APDF (p < 0.05). There was also a significant difference in the time spent working in an extreme posture of the back and head between groups (p < 0.05). Conclusions: This is the first study to document work postures assumed during a full work shift and to compare postures between symptomatic and healthy overhead crane operators. Physical exposure in case group operators was characterized by more awkward and extreme postures in the back and head. The results of this study demonstrate that effective prevention strategies directed towards musculoskeletal disorders are required that address awkward work postures for overhead crane operators.
Objectives: This report reviews the carcinogenicity of multi-walled carbon nanotubes (MWCNTs) in experimental animals, concentrating on MWNT-7, a straight fibrous MWCNT. Methods: MWCNTs were administered to mice and rats by intraperitoneal injection, intrascrotal injection, subcutaneous injection, intratracheal instillation and inhalation. Results: Intraperitoneal injection of MWNT-7 induced peritoneal mesothelioma in mice and rats. Intrascrotal injection induced peritoneal mesothelioma in rats. Intratracheal instillation of MWCNT-N (another straight fibrous MWCNT) induced both lung carcinoma and pleural mesothelioma in rats. In the whole body inhalation studies, in mice MWNT-7 promoted methylcholanthrene-initiated lung carcinogenesis. In rats, inhalation of MWNT-7 induced lung carcinoma and lung burdens of MWNT-7 increased with increasing concentration of airborne MWNT-7 and increasing duration of exposure. Conclusions: Straight, fibrous MWCNTs exerted carcinogenicity in experimental animals. Phagocytosis of MWCNT fibers by macrophages was very likely to be a principle factor in MWCNT lung carcinogenesis. Using no-observed-adverse-effect level-based approach, we calculated that the occupational exposure limit (OEL) of MWNT-7 for cancer protection is 0.15 μg/m3 for a human worker. Further studies on the effects of the shape and size of MWCNT fibers and mode of action on the carcinogenicity are required.
Objectives: Human resources (HR) are essential indicators of safety and health (SH) status, and HR can be key sources of workplace safety management such as safety and health education at work (SHEW). This study analyzed significant HR factors associated with SHEW of small manufacturing businesses in Korea. Methods: The secondary data of the 2012 Korea Occupational Safety and Health Trend Survey were used to achieve this research purpose. A total of 2,089 supervisors or managers employed in the small manufacturing businesses completed the interview survey. Survey businesses were selected by multiple stratified sampling method based on industry code, business size, and region in Korea. The survey included workplace characteristics of HR and SHEW. Results: SHEW was significantly related to business size, occupational injury incidence in the previous year, foreign and elderly worker employment, presence of site supervisors, and presence of SH committees (p <.05). SHEW for office workers, non-office workers, and newcomers was associated with business size, presence of site supervisors, and presence of SH committees in logistic regression analysis (p <.001). Businesses with 30–49 workers conducted SHEW 3.64 times more than did businesses with 5 to fewer than 10 workers. The companies that had occupational injuries in the previous year conducted SHEW 1.68 times more than the others. The businesses that had site supervisors and committees conducted SHEW 2.30 and 2.18 times more, respectively, than others. Conclusions: Site supervisors and SH committees were significant HR factors that improved SHEW in small manufacturing businesses.
Expert Division of Occupational Hygiene & Ergonomics, the Japan Society for Occupational Health, "The Committee for Personal Exposure Monitoring", Haruo Hashimoto, Kenichi Yamada, Hajime Hori, Shinji Kumagai, Masaru Murata, Toshio Nagoya, Hirohiko Nakahara, Nobuyuki Mochida
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.
Objectives: For occupational health (OH) nurses to perform activities effectively, not only skills and knowledge but also competencies proposed by Dr. McClelland are indispensable. This study aimed to identify competencies required for OH nurses and to show their structure diagram.
Methods: Qualitative descriptive research was conducted from October 2010 to August 2011. Eight high-performing OH nurses participated, and data were collected from semi-structured interviews held for each nurse. Data were qualitatively and inductively analyzed using the KJ method.
Results: Seven competencies were identified: "self-growth competency," "OH nursing essence perpetuation competency," "strategic planning and duty fulfillment competency," "coordination competency," "client growth support competency," "team empowerment competency," and "creative competency." A structure diagram of the seven competencies was clarified. As the definitions of the competencies were different, the findings of competencies for OH nursing in the United States of America (USA) could not simply be compared with the findings of our study; however, all seven competencies were compatible with those in AAOHN model 1 and AAOHN model 2 in the USA.
Conclusion: Our seven competencies are essential for OH nurses to perform activities that meet the expectations of employees and the employer.
Objective: We utilized job safety analysis (JSA) and hazard identification for work accident prevention in Para rubber wood sawmills, which aimed to investigate occupational health risk exposures and assess the health hazards at sawmills in the Trang Province, located in southern Thailand. Methods: We conducted a cross-sectional study which included a walk-through survey, JSA, occupational risk assessment, and environmental samplings from March through September 2015 at four Para rubber wood sawmills. Results: We identified potential occupational safety and health hazards associated with six main processes, including: 1) logging and cutting, 2) sawing the lumber into sheets, 3) planing and re-arranging, 4) vacuuming and wood preservation, 5) drying and planks re-arranging, and 6) grading, packing, and storing. Working in sawmills was associated with high risk of wood dust and noise exposure, occupational accidents injuring hands and feet, chemicals and fungicide exposure, and injury due to poor ergonomics or repetitive work. Discussion: Several high-risk areas were identified from JSA and hazard identification of the working processes, especially high wood dust and noise exposure when sawing lumber into sheets and risk of occupational accidents of the hands and feet when struck by lumber. All workers were strongly recommended to use personal protective equipment in any working processes. Exposures should be controlled using local ventilation systems and reducing noise transmission. We recommend that the results from the risk assessment performed in this study be used to create an action plan for reducing occupational health hazards in Para rubber sawmills.
Objectives: The application of multiwall carbon nanotubes (MWCNTs) currently extends to various fields. However, it has been reported that exposure to CNT causes hazardous effects on animals and cells. The purpose of this study was to quantify the exposure to MWCNT in MWCNT/polymer composites for exposure assessment. We focused on catalytic metals included in the MWCNT and the diameter of dust released during the working processes. Although the Co in MWCNTs is not a common catalyst, it was used as a tracer in this study. Methods: A field survey was conducted in a MWCNT/polymer composite pilot factory. Airborne MWCNTs were monitored using black carbon monitors (BCMs) and optical particle sizers (OPSs) and collected on a filter. The MWCNT powder, all polymer resins used during the working processes, and the filter were analyzed in our lab using inductively coupled plasma mass spectrometry (ICP-MS) and electron microscopic observation. Results: The mean concentration of airborne MWCNT contained in the collected dust was 0.92 μg/m3 a few meters away from the extruder during the working processes (using elemental analysis). The maximum concentration measured using BCMs was shown to be seven times higher than the base concentration during the pelletizing process of polycarbonate (PC) and MWCNT composites. However, free, isolated, and unbound agglomerated MWCNTs were not detected using scanning electron microscopic (SEM) observation. Conclusions: The result obtained by elemental analysis indicated it was possible to quantify MWCNT in composites. The mean concentration at this factory was lower than the recommended exposure limit. However, additional studies during the pelletizing process are required in the future.
Objectives: Nanoparticles (NPs), including hazardous substances, are generated in crematoriums due to the high temperatures during the combustion process. NPs are reported to greatly impact animals' health by reaching the alveoli and being carried to the entire body through the blood stream. However, studies in crematoriums have yet to assess workers' exposure to the generated NPs. The purpose of this study is to assess workers' exposure to NPs released in crematoriums. Methods: Field surveys were conducted in three crematoriums with an emphasis on cremation, bone rearrangement and cleaning processes. The NP concentrations and size distributions were analyzed. The deposition of NPs in each respiratory region during each working process was calculated based on the measured data using the Human Respiratory Tract Model. Results: The mean particle number concentration was maximized momentarily during the bone rearrangement process. The concentration at the time a crematory's door was opened was 500,000 particle/cm3. NPs aggregated to micro-sized particles within a few minutes, dust generated by the bone rearrangement, or both. As a result of model calculation, the mean ratios (alveolar per the other regions by a crematory) were approximately 3.0 (bronchus and bronchioles regions: except for the first survey in crematorium A which had the obstruction of measurement) and 4.3 (extrathoracic airways). The ratios were similar for all crematoriums. Conclusions: These results can be used for health risk assessments in crematoriums. In addition, these results should be applicable to estimate the inhalation unit risk of each respiratory organ such as lungs and nose.
Burnout constitutes a health risk, and interventions are needed to reduce it.
The aim of this study was to synthesize evidence regarding the relationship between physical activity and burnout by conducting a systematic review of longitudinal and intervention studies.
A literature search resulted in the identification of a final set of ten studies: four longitudinal and six intervention studies. In separate analyses for each category, evidence was synthesized by extracting the study characteristics and assessing the methodological quality of each study. The strength of evidence was calculated with the standardized index of convergence (SIC).
In longitudinal studies, we found moderately strong evidence (SIC(4)= −1) for a negative relationship between physical activity and the key component of burnout, i.e., exhaustion. We found strong evidence (SIC(6)= −0.86) for the effect of physical activity on reducing exhaustion in intervention studies. As only one study could be classified as a high quality study, these results of previous studies need to be interpreted with some caution.
This systematic review suggests that physical activity constitutes an effective medium for the reduction of burnout. Although consistent evidence was found, there is a lack of high quality longitudinal and intervention studies considering the influence of physical activity on burnout. Therefore, future research should be conducted with the aim to produce high quality studies, to develop a full picture of physical activity as a strategy to reduce burnout.
Objectives: Sickness presenteeism (SP) is postulated as workers' response to their general state of health; hence, SP is expected to affect workers' future health. In the present study, we examined the reciprocal relationship between SP and health in response to job stressors, with specific reference to psychological distress (PD) as workers' state of health.
Methods: We conducted mediation analysis, using data from a three-wave cohort occupational survey conducted at 1-year intervals in Japan; it involved 1,853 employees (1,661 men and 192 women) of a manufacturing firm. We measured SP and PD, using the World Health Organization Health and Work Performance Questionnaire and Kessler 6 score, respectively. For job stressors, we considered job demands and control, effort and reward, and procedural and interactional justice.
Results: PD mediated 11.5%–36.2% of the impact of job control, reward, and procedural and interactional justice on SP, whereas SP mediated their impact on PD, albeit to a much lesser extent in the range of 3.4%–11.3%. Unlike in the cases of these job stressors related to job resources, neither SP nor PD mediated the impact of job demands or effort.
Conclusions: Our results confirmed the reciprocal relationship between SP and PD in response to selected types of job stressors, emphasizing the need for more in-depth analysis of the dynamics of these associations.
Objectives: The aims of present study were to determine the prevalence of work-related musculoskeletal disorders (WRMSDs) among sonographers in China and to provide evidence for appropriate intervention measures to be taken. Methods: A self-reported questionnaire was used to screen WRMSDs experienced by sonographers during the past 12 months. This questionnaire survey was created and hosted on the WeChat official account platform for sonographers. Results: In the present study, 567 sonographers from 521 medical institutions completed the questionnaire. The vast majority (99.3%) of respondents reported experiencing symptoms of WRMSDs for at least one body region during the past 12 months. Work-related musculoskeletal pain or discomfort was most frequently reported for the neck (95.1%), right shoulder (84.1%), lower back (82.4%), right wrist/hand (81.0%), upper back (78.1%), right forearm/elbow (72.0%), and left shoulder (66.1%). Scanning hours per day, number of patients per day, and years of experience were positively associated with the occurrence and frequency of experiencing WRMSDs of some common and specific anatomical regions. Taking a regular rest break during the scanning working day was associated with a reduction of WRMSDs of the right shoulder and right wrist/hand. Adopting a sitting posture while performing scanning was associated with a reduction of WRMSDs, particularly for the lower back and the neck. Performing regular physical activity during leisure time was associated with a reduction of WRMSDs of the neck. Conclusions: The prevalence of WRMSDs among sonographers in China was extremely high. It is necessary and essential to reduce the number of scanning hours and patients per day, adopt a sitting posture while performing scanning, schedule regular rest breaks during the scanning working day, and encourage performance of regular physical activity during leisure time to alleviate this WRMSD issue experienced by sonographers.
Health care workers (HCWs) face risks of needle stick and sharp injuries (NSIs). Most NSIs occur in developing countries, however, no epidemiological study on NSIs is publicly available in Lao PDR. The objective of this study is to identify the prevalence and risk factors of NSIs among HCWs in Lao PDR.
This cross-sectional study was designed to determine the prevalence and risk factors of NSIs among four tertiary hospitals in Vientiane, Lao People's Democratic Republic.
Six months before the survey, 11.4% (106/932) of hospital staff had experienced NSIs, while 42.1% did in their entire career. Key protective factors of NSIs among nurses included adequate availability of needles, syringes, and sharp equipment (p = 0.042; odds ratio [OR], 0.47) and attendance to educational or refresher courses on safety regarding NSIs (p = 0.038; OR, 0.50). As an on-site practice, single-handed recapping was prevalent (46.7%, 257/550) among participants.
The result showed that high rates of NSIs persist among HCWs. The findings of this research call for comprehensive health and injection safety programs for HCWs involved in clinical practice.
Objectives: Work-related carpal tunnel syndrome (CTS) has been reported in different occupations, including laboratory technicians, so this study was carried out to determine the prevalence and the associated personal and ergonomic factors for CTS among laboratory technicians.
Methods A cross-sectional study was conducted among 279 laboratory technicians at King Fahd Hospital, Saudi Arabia, who filled in a self-administered questionnaire, including questions regarding their demographic criteria, occupational history, job tasks, workplace tools, ergonomic factors at work, and symptoms suggestive of CTS. Physical examinations and electrodiagnostic studies were carried out for those who had symptoms suggestive of CTS to confirm the diagnosis. Univariate and multivariate analysis were performed for both personal and physical factors in association with confirmed CTS among laboratory technicians.
Results: The prevalence of CTS among the laboratory technicians was 9.7% (27/279). The following were the statistically significant risk factors for CTS among them: gender (all cases of CTS were female, P = 0.00), arm/hand exertion (OR:7.96; 95% CI: 1.84–34.33), pipetting (OR:7.27; 95% CI: 3.15–16.78), repetitive tasks (OR: 4.60; 95% CI: 1.39–15.70), using unadjustable chairs or desks (OR:3.35; 95% CI: 1.23–9.15), and working with a biosafety cabinet (OR: 2.49; 95% CI: 1.11–5.59). CTS cases had significant longer work duration (17.9 ± 5.6 years) than CTS non-case (11.5 ± 7.4 yeas) with low OR (1.108).
Conclusion: This study demonstrates some personal and ergonomic factors associated with CTS among the laboratory technicians, including female gender, arm/hand exertion, pipetting, repetitive tasks, working with a biosafety cabinet, and an unadjusted workstation.
Objectives: The objective of this study was to validate a short version of the Effort-Reward-Imbalance (ERI) questionnaire in the context of New Zealand among older full-time and part-time employees.
Methods: Data were collected from 1694 adults aged 48–83 years (mean 60 years, 53% female) who reported being in full- or part-time paid employment in the 2010 wave of the New Zealand Health, Work and Retirement study. Scale reliability was evaluated by item-total correlations and Cronbach's alpha. Factorial validity was assessed using multi-group confirmatory factor analyses assessing nested models of configural, metric, scalar and strict invariance across full- and part-time employment groups. Logistic regressions estimated associations of effort-reward ratio and over-commitment with poor physical/mental health, and depressive symptoms.
Results: Internal consistency of ERI scales was high across employment groups: effort 0.78–0.76; reward 0.81–0.77, and over-commitment 0.83–0.80. The three-factor model displayed acceptable fit in the overall sample (X2/df = 10.31; CFI = 0.95; TLI = 0.94; RMSEA = 0.075), and decrements in model fit indices provided evidence for strict invariance of the three-factor ERI model across full-time and part-time employment groups. High effort-reward ratio scores were consistently associated with poor mental health and depressive symptoms for both employment groups. High over-commitment was associated with poor mental health and depressive symptoms in both groups and also with poor physical health in the full-time employment group.
Conclusions: The short ERI questionnaire appears to be a valid instrument to assess adverse psychosocial work characteristics in old full-time and part-time employees in New Zealand.
Objectives: Objective measurements using built-in smartphone sensors that can measure physical activity/inactivity in daily working life have the potential to provide a new approach to assessing workers' health effects. The aim of this study was to elucidate the characteristics and reliability of built-in step counting sensors on smartphones for development of an easy-to-use objective measurement tool that can be applied in ergonomics or epidemiological research.
Methods: To evaluate the reliability of step counting sensors embedded in seven major smartphone models, the 6-minute walk test was conducted and the following analyses of sensor precision and accuracy were performed: 1) relationship between actual step count and step count detected by sensors, 2) reliability between smartphones of the same model, and 3) false detection rates when sitting during office work, while riding the subway, and driving.
Results: On five of the seven models, the inter-class correlations coefficient (ICC (3,1)) showed high reliability with a range of 0.956–0.993. The other two models, however, had ranges of 0.443–0.504 and the relative error ratios of the sensor-detected step count to the actual step count were ±48.7%–49.4%. The level of agreement between the same models was ICC (3,1): 0.992–0.998. The false detection rates differed between the sitting conditions.
Conclusions: These results suggest the need for appropriate regulation of step counts measured by sensors, through means such as correction or calibration with a predictive model formula, in order to obtain the highly reliable measurement results that are sought in scientific investigation.
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.