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: Legionnaires' disease (LD), which is atypical pneumonia with a broad variety of clinical symptoms, can lead to death despite its low incidence. There are multiple risk factors for LD, yet little information is available concerning what kind of environmental factors are linked to higher risk of LD development. We have experienced a fatal case of LD, which occurred in a decontamination worker after the Fukushima nuclear disaster.
Case: A 53-year-old Japanese male visited our hospital with symptoms of fever, vomiting, diarrhea, and altered mental status, but not with respiratory manifestations. He was engaged in decontamination work, which generally includes operations such as the removal of topsoil in mountainous areas and cleaning roads and roofs of residential buildings with high-pressure water. He was required to wear specific equipment to prevent radiation exposure, and lived in a workers' dormitory or shared house, thereby sharing spaces with other workers.
Normal antibiotic therapy did not improve his symptoms following his diagnosis with pneumonia. A urinary antigen detection test was then conducted, leading to a diagnosis of LD. Despite the change of antibiotic to levofloxacin, multiple organ failure led to his death.
Conclusion: Decontamination workers may be at a high risk for developing LD and living and working conditions among them are possible contributors.
Objectives: This study aimed to describe the sleep quantity, sleep quality, and daily rest periods (DRPs) of Japanese permanent daytime workers.
Methods: Information about the usual DRP, sleep quantity, and sleep quality (Japanese version of the Pittsburgh Sleep Quality Index: PSQI-J) of 3867 permanent daytime workers in Japan was gathered through an Internet-based survey. This information was analyzed and divided into the following eight DRP groups: <10, 10, 11, 12, 13, 14, 15, and ≥16 h.
Results: The sleep durations for workers in the <10, 10, 11, 12, 13, 14, 15, and ≥16 h DRP groups were found to be 5.3, 5.9, 6.1, 6.3, 6.5, 6.7, 6.7, and 6.9 h, respectively. The trend analysis revealed a significant linear trend as the shorter the DRP, the shorter was the sleep duration. The PSQI-J scores for the <10, 10, 11, 12, 13, 14, 15, and ≥16 h DRP groups were 7.1, 6.7, 6.7, 6.3, 6.0 (5.999), 5.6, 5.2, and 5.2, respectively. The trend analysis revealed a significant linear trend as the shorter the DRP, the lower was the sleep quality.
Conclusions: This study described sleep quantity, sleep quality, and DRP in Japanese daytime workers. It was found that a shorter DRP was possibly associated with poorer sleep quantity as well as quality.
Objective: To determine the convergent validity and responsiveness of the work functioning impairment scale (WFun) in workers with musculoskeletal disorder–related pain.
Methods: Participants were extracted from an internet user study and prospectively examined using the pain intensity numerical rating scale (pain-NRS), the work ability numerical rating scale (productivity-NRS), and the WFun at baseline, 2 weeks, 6 weeks, and 3 months. The convergent validity and responsiveness of the WFun were examined by multilevel regression analysis.
Results: A total of 786 workers participated and 593 completed all surveys. The WFun score gradually increased and decreased as the pain-NRS and the productivity-NRS increased, respectively. Changes in the WFun score steadily increased and decreased as changes in the pain-NRS and the productivity-NRS increased, respectively. Multilevel analyses showed that all linear associations were significant.
Conclusions: The convergent validity and responsiveness of the WFun were consistent with the expected direction and magnitude.
Work stress among nurses has increased in recent years due to the demands of clinical nursing
To investigate psychosocial work stress among nurses using the effort–reward imbalance (ERI) model with assessment malondialdehyde (MDA) as an oxidative stress marker and total antioxidants.
The present study was conducted on 204 registered nurses worked at two tertiary hospitals in Menoufia governorate, Egypt through the period from the 1st of February to the end of July 2016. Two questionnaires were applied including general demographic and occupational histories as well as effort–reward questionnaire. Blood analysis was performed to assess MDA and total antioxidant levels.
ERI was prevalent among the study participants (72.5%). ERI was more prevalent among young married nurses who worked more than 10 years. Nurses that worked at ICUs complained more of ERI (43.2%) while nurses that worked at operation rooms complained more of overcommitment (62.5%). MDA levels were significantly positively correlated with E/R ratios (rho = 0.350, P ≤ 0.001)
Work stress was prevalent among the studied nurses as revealed by the high ERI and MDA levels. Young married female nurses complained more of work stress. ICUs and operating rooms were the most stressful departments at the studied hospitals. Hence, implementing programs and strategies that eliminate stressful working conditions at hospitals is critical to the reduction and prevention of work stress among nurses.
With the immense economic growth and social development, China has gained worldwide attention. With the quick growth of industrialization, several international professionals are gaining interest in occupational management system and in the role of the Chinese Government in protecting the worker's health. The Law on Prevention and Control of Occupational Diseases and the Work Safety Law are the two most important laws in China, which highlight the responsibilities of the employer, employee, governmental agencies, authorized occupational health service agency, and other stakeholders. The State Council comprises two departments, namely, the State Administration on Work Safety (SAWS) and the National Health and Family Planning Commission (NHFPC), which are responsible for governing the occupational health work. A series of regulations and standards have been promulgated by the Chinese Government to encourage or instruct the employers to fulfill their responsibility; however, several issues persist related to occupational health work, including administrative, technological, and sociocultural aspects. At present, the Chinese Government wants to enhance the reform in both economic and administrative structures, and the adjustments for modifying and/or improving the occupational health regulatory system are expected. Notably, the occupational health work in China must be altered for better.
Objectives: This study aimed to elucidate the effects of two naps taken at night on morning waking state and performance.
Methods: The participants were 12 women. The experiment was performed in a laboratory over 2 days (16:00–09:00). In this crossover comparative study, three experimental nap conditions were used (naps from 22:30 to 00:00 and from 02:30 to 03:00 (22:30-NAP), 00:30 to 02:00 and 04:30 to 05:00 (00:30-NAP), and no naps (NO-NAP), respectively). Measurement items were a Visual Analog Scale for sleepiness and fatigue, the Psychomotor Vigilance Test (PVT), and single-digit addition calculations (10 min) every hour for 18 h from 16:00 to 09:00, excluding nap times.
Results: Sleep inertia and sleepiness were noted directly after napping. Less sleepiness and fatigue were noted in the nap groups between 06:00 and 09:00 in the morning than in the NO-NAP condition and PVT response times were faster. Since participants in the nap groups were able to conduct more single-digitaddition calculations, the performance of these groups appeared to be superior to that of the NO-NAP condition. Furthermore, the performance of calculations was significantly better in the 00:30-NAP than in the 22:30-NAP.
Conclusions: Taking two naps during a simulated night shift helps improve sleepiness and fatigue and maintain performance. Taking a nap in the early morning appears to be promising for improving the waking state.
Objectives: The purpose of this research was to develop a method for monitoring personal exposure to benzyl violet 4B (BV) and direct blue 15 (DB) in workplace air for risk assessment. Methods: We evaluated the utility of the proposed method by examining the following: recovery; method limit of quantification; reproducibility; and storage stability of the samples. Results: An air sampling cassette containing a glass fiber filter was chosen as the sampler. BV and DB were extracted from the sampler filters with a solution of water and methanol (7:3, v/v) and then analyzed by a high-performance liquid chromatograph equipped with a photo-diode array detector. The overall recoveries from spiked samplers were 94–102% and 94–99% for BV and DB, respectively. The recovery after seven days of storage at 4°C exceeded 95%. The method limits of quantification were 0.250 and 1.25 μg/sample for BV and DB, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.6–4.1% and 0.8–2.9% for BV and DB, respectively. Conclusions: The proposed method enables 4 h personal exposure monitoring of BV and DB at concentrations of 1–2,000 μg/m3 for BV and 5–2,000 μg/m3 for DB, with a 240 l sampling. Thus, the proposed method is useful for estimating worker exposure to BV and DB.
Background: We examined the effects of challenge stress and hindrance stress on general health and presenteeism among Chinese healthcare workers.
Methods: Structural equation modeling was used to evaluate data from a national hospital survey in China (n = 1392). Job stress, general health, and presenteeism were measured by the Perceived Ability to Work Scale, the 8-item Short-Form Health Survey, and the Challenge- and Hindrance-Related Self-reported Stress Scale.
Results: Challenge stress and hindrance stress were significantly positively correlated (β = 0.62, SE = 0.021; p < 0.001). Challenge stress was directly negatively associated with presenteeism (β = −0.05, SE = 0.037; p < 0.001;), while hindrance stress was positively associated with presenteeism (β = 0.25, SE = 0.040; p < 0.001). These associations with presenteeism were partially mediated by health.
Conclusions: Hospital managers should provide healthcare workers with an appropriate level of challenge, but employee health is the most important consideration. Further efforts targeting job stress and health of junior healthcare workers are required.
Objectives:N,N-Dimethylacetamide (DMAC) is widely used in industry as a solvent. It can be absorbed through human skin. Therefore, it is necessary to determine exposure to DMAC via biological monitoring. However, the precision of traditional gas chromatography (GC) is low due to the thermal decomposition of metabolites in the high-temperature GC injection port. To overcome this problem, we have developed a new method for the simultaneous separation and quantification of urinary DMAC metabolites using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Methods: Urine samples were diluted 10-fold in formic acid, and 1-μl aliquots were injected into the LC-MS/MS equipment. A C18 reverse-phase Octa Decyl Silyl (ODS) column was used as the analytical column, and the mobile phase consisted of a mixture of methanol and aqueous formic acid solution.
Results: Urinary concentrations of DMAC and its known metabolites (N-hydroxymethyl-N-methylacetamide (DMAC-OH), N-methylacetamide (NMAC), and S-(acetamidomethyl) mercapturic acid (AMMA)) were determined in a single run. The dynamic ranges of the calibration curves were 0.05–5 mg/l (r ≥ 0.999) for all four compounds. The limits of detection for DMAC, DMAC-OH, NMAC, and AMMA in urine were 0.04, 0.02, 0.05, and 0.02 mg/l, respectively. Within-run accuracies were 96.5%–109.6% with relative standard deviations of precision being 3.43%–10.31%.
Conclusions: The results demonstrated that the proposed method could successfully quantify low concentrations of DMAC and its metabolites with high precision. Hence, this method is useful for evaluating DMAC exposure. In addition, this method can be used to examine metabolite behaviors in human bodies after exposure and to select appropriate biomarkers.
Background: Numerous workers have participated in recovery efforts following the accident that occurred at the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Plant after the Great East Japan Earthquake. These workers, belonging to various companies, have been engaged in various tasks since the accident. Given the hazards and stress involved in these tasks and the relatively long time required to transport sick or injured workers to medical institutions, it became necessary to quickly implement a more stringent management program for fitness for duty than in ordinary work environments. Case: It took considerable time to introduce and improve a fitness-for-duty program because of several concerns. Various efforts were conducted, sometimes triggered by guidance from the Ministry of Health, Labour and Welfare (MHLW), but the implementation of the program was insufficient. In April 2016, a new program was initiated in which all primary contractors confirmed that their subcontractors had achieved five conditions for workers' fitness for duty on the basis of guidance from the MHLW and occupational health experts. TEPCO confirmed that all primary contractors had implemented the program successfully as of the end of November 2016. Conclusion: Following a disaster, even though the parties concerned understand the necessity of fitness-for-duty programs and that companies in high positions have responsibilities beyond their legal requirements, it is highly possible that they may hesitate to introduce such programs without guidance from the government. It is necessary to prepare a governmental framework and professional resources that introduce these stringent management programs quickly.
The study was conducted to report on the scope and prevalence of occupational health related-problems experienced by dentists, dental therapists, and oral hygienists in their practice of dentistry.
Background: Professional practice and dental training have many risk factors, and the dental team should be able to recognize these factors to protect themselves. The prevalence of conditions related to the musculoskeletal system, stress, percutaneous injuries, ears, and eyes are of concern. The dental team should also not forget hepatitis B, hepatitis C, and HIV as risks in practice. Dental practitioners should protect themselves by self-recognizing risk factors and by maintaining proper working conditions.
Methods: The study targeted all empirical research, case studies, and systematic literature reviews written in English. All articles selected were subjected to a data analysis process. Data were captured on an Excel spreadsheet and reported in a comprehensive table.
Results: The literature addressing occupational health among dental practitioners included mainly cross-sectional studies and review papers (2001–2016). Forty-nine studies were included in the review. Musculoskeletal disorders remain the most researched occupational health–related problems in dentistry. Eye protection compliance was low among practitioners. Percutaneous injuries especially among young dentists and students were still a concern.
Conclusion: Occupational health–related problems are still prevalent in current dentistry practice, despite changes in equipment and surgery design. The reported prevalence of occupational related-health problems and other findings of investigative studies highlight the need for continuous professional education and a need to improve clinical practice aspects of dentistry curricula.
Objectives: Indium compounds are used in manufacturing displays of mobile phones and televisions. However, these materials cause interstitial pneumonia in exposed workers. Animal experiments demonstrated that indium compounds caused lung cancer. Chronic inflammation is considered to play a role in lung carcinogenesis and fibrosis induced by particulate matters. 8-Nitroguanine (8-nitroG) is a mutagenic DNA lesion formed during inflammation and may participate in carcinogenesis. To clarify the mechanism of carcinogenesis, we examined 8-nitroG formation in indium-exposed cultured cells.
Methods: We treated RAW 264.7 mouse macrophages with indium oxide (In2O3) nanoparticles (primary diameter: 30–50 nm), and performed fluorescent immunocytochemistry to detect 8-nitroG. The extent of 8-nitroG formation was evaluated by quantitative image analysis. We measured the amount of nitric oxide (NO) in the culture supernatant of In2O3-treated cells by the Griess method. We also examined the effects of inhibitors of inducible NO synthase (iNOS) and endocytosis on In2O3-induced 8-nitroG formation.
Results: In2O3 significantly increased the intensity of 8-nitroG formation in RAW 264.7 cells in a dose-dependent manner. In2O3-induced 8-nitroG formation was observed at 2 h and further increased at 4 h, and the amount of NO released from In2O3-exposed cells was significantly increased at 2–4 h compared with the control. 8-NitroG formation was suppressed by 1400W (an iNOS inhibitor), methyl-β-cyclodextrin and monodansylcadaverine (inhibitors of caveolae- and clathrin-mediated endocytosis, respectively).
Conclusions: These results suggest that endocytosis and NO generation participate in indium-induced 8-nitroG formation. NO released from indium-exposed inflammatory cells may induce DNA damage in adjacent lung epithelial cells and contribute to carcinogenesis.
Objectives: The purposes of this study were to clarify 1) the prevalence of foot and ankle pain and 2) the factors associated with foot and ankle pain among nurses. Methods: Nurses working at a university hospital in Japan were recruited to participate in this cross-sectional, questionnaire-based study. The occurrence of foot and ankle pain in the previous month was assessed by using the Standardized Nordic Questionnaire and the Manchester Foot Pain and Disability Index. Subjects also answered questions on footwear-related factors, including using the visual analog scale for shoe comfort. In addition, information on personal factors and psychosocial factors was collected using the Job Content Questionnaire. The relationships between the presence of foot and ankle pain and the associated factors were examined using multiple logistic regression analysis. Results: Responses of 636 nurses (response rate, 67%) were included for analysis. The prevalence of foot and ankle pain was 23% and 51% when using the Standardized Nordic Questionnaire and the Manchester Foot Pain and Disability Index, respectively. The prevalence of pain that prevented the nurses from performing activities of daily living and work was 4% and 17%, respectively. A low level of shoe comfort, personal factors (age and body mass index), and psychosocial factors (low job control and high job strain) was independently associated with the presence of foot and ankle pain. Conclusions: Foot and ankle pain occurred frequently in nurses. Shoe comfort, personal factors, and psychosocial factors were associated with foot and ankle pain.
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.