Objectives: The aim of this study was to identify bacteria in sludge brought by the 2011 tsunami in Japan to determine the necessary precautions for workers who handle the sludge. Methods: Two sludge samples and one water sample were collected from each of two sites in Miyagi Prefecture in June 2011. We also obtained control samples from a paddy field and a dry beach in Fukuoka, Japan. The samples were subjected to physicochemical analyses, conventional cultivation methods, and molecular methods for bacterial flora analysis. The bacterial floras were analyzed using a clone library method employing fragments of the 16S ribosomal RNA gene (rDNA) amplified with universal primers. Results: We detected 51–61 genera in sludge samples and 14 and 17 genera in water samples collected in the tsunami-affected areas. In sludge samples collected in the tsunami-affected areas, more genera belonged to Proteobacteria than to Bacteroidetes, but in water samples collected in these areas, more genera belonged to Bacteroidetes than to Proteobacteria. Non-O1, non-O139 V. cholerae (non-agglutinable vibrio) was found at approximately 104 cells/m/ near the coast of the tsunami affected area. Sulfate-reducing bacteria were detected in sludge collected from the paddy field, and a relatively high concentration of sulfate ions was found in the water sample (258 mg/l). Conclusions: Sludge brought by the tsunami contained some pathogens; therefore, frequent hand washing is recommended for workers who have direct contact with the sludge to minimize their risk of infection. Under the anaerobic conditions of paddy fields, hydrogen sulfide could be produced by sulfate-reducing bacteria metabolizing sulfate ions.
Objectives: The aim of this study was to estimate a benchmark dose (BMD) for chromosome damage induced by vinyl chloride monomer (VCM) in VCM-exposed workers in central China and validate the published results in Shanghai. Methods: VCM-exposed workers who had been exposed to VCM for at least one year (n=463) and matched subjects not exposed to VCM or other toxins (n=273) were asked to participate in this study. Micronucleus (MN) frequency based on the cytokinesis-block micronucleus assay (CBMN) was used as a biomarker for chromosome damage induced by VCM exposure. Results: The MN frequency in the VCM-exposed workers was significantly higher than that in the control group, and multivariate Poisson regression suggested that gender, smoking status and VCM exposure were the significant factors influencing the risk of increased MN frequency. When subjects were further stratified according to gender and smoking status, the results showed that female VCM-exposed workers were more susceptible than the males to the risk of increased MN frequency. The MN frequency of smokers was significantly higher than that of nonsmokers in the control group. Our study also suggested that there was a strong dose-response relationship between VCM CED and the increased risk of MN frequency in the total group, males and females. The BMDL10 was found to be 630.6, 670.2 and 273.7 mg-year for all VCM-exposed workers, males and females, respectively. Conclusions: These results invite further scrutiny of the current VCM occupational exposure limits and warrant further study of the risk of VCM genotoxicity and carcinogenicity.
Objective: The aim of this study was to investigate the effects of an EMG-based feedback device on the human musculoskeletal system by assessing the kinematics of the lumbar and cervical regions during computer operation. Methods: Using an EMG device, measurements were collected under four conditions: with feedback from the upper trapezius muscle, from the L4-erector spinae muscles and from both and without feedback (control). During periods of 15 min of computer operation, kinematic data were collected using the Zebris motion analysis system to investigate 14 university employees. Results: Feedback assessment effectively reduced the kinematic changes in the sagittal plane compared with the control (p<0.05). Feedback from the L4 erector spinae reduced the trunk flexion and forward head angles, which were significantly different compared with those under the feedback from the upper trapezius and the control conditions (p<0.05). Conclusion: We observed that the use of an EMG-based feedback device was effective in reducing habitual forward head and flexed-relaxed postures during computer operation. Additionally, posture correction from the lumbar region could be a way to reduce forward head posture as well as flexed-relaxed posture.
Objectives: The aim of this study was to assess the effects of individual and work-related factors on the incidence of shoulder pain in a large French working population. Methods: A total of 3,710 workers of a French region were randomly included in a cross-sectional study between 2002 and 2005. They completed a self-administered questionnaire about musculoskeletal symptoms, individual factors and exposure to work constraints. In 2007, 2,332 responded to a follow-up questionnaire. The Nordic questionnaire was used both times to assess shoulder pain during the preceding 7 days. Associations between incident shoulder pain and individual and work-related factors at baseline were studied by multivariate logistic regression for both genders. Results: A total of 946 men and 709 women without shoulder pain at baseline were eligible for the analyses. At follow-up, 105 men (11.1%) and 145 women (20.5%) reported shoulder pain. For men, age (OR 3.3, 95% CI, 1.7–6.5 for ≥50 yr), working with arms above the shoulder (1.5; 1.0–2.3) and high perceived physical exertion (1.6; 1.0–2.5) increased the risk of incident shoulder pain. For women, the factors associated with incident shoulder pain were age (2.9; 1.5–5.8 for ≥50 yr), obesity (2.5; 1.4–4.5), temporary employment (2.1; 1.1–3.7), high perceived physical exertion (2.2; 1.4–3.5) and low decision latitude (1.6; 1.0–2.3). Conclusion: Age was the strongest predictor of incident shoulder pain in both genders. BMI and biomechanical and psychosocial factors were also identified as risk factors, whereas no factor related to work organization remained in the final models.
Introduction: After a traumatic event, a significant proportion of victims develop psychiatric disorders. Trauma has been an important ailment among workers. This study aimed to determine the prevalence of post-traumatic stress disorder (PTSD) and other psychiatric disorders at three months after occupational injuries. Methods: Our study candidates were injured workers in Taiwan who were hospitalized for 3 days or longer and received hospitalization benefits from the Labor Insurance program. A two-staged survey study was conducted. A self-reported questionnaire including the Brief Symptom Rating Scale (BSRS-50) and Post-traumatic Symptom Checklist (PTSC) was sent to workers at 3 months after injury. Those who met the criteria were recruited for the second stage phone interview with a psychiatrist using the Mini-international Neuropsychiatrie Interview (MINI). Results: A total of 2001 workers completed the questionnaire (response rate 45.5%). Among them, 357 (17.8%) fulfilled the criteria for the MINI interview and were invited. A total of 148 (41.5%) completed the phone interview. The estimated rates of PTSD, partial PTSD (PPTSD), major depression, comorbid PTSD/PPTSD and major depression, and either PTSD/PPTSD or major depression were 2.7, 4.1, 3.0, 2.3, and 7.5%, respectively. The estimated rates of either PTSD/PPTSD or major depression among workers who suffered from intracranial injury, fracture, burn, crushing injury, and open wound of upper limbs were 10.4, 6.9, 5.9, 5.8 and 0%, respectively. Conclusions: At three months after occupational injuries, a significant proportion of workers suffered from psychiatric disorders. The rates of psychiatric disorders occurring after intracranial injuries were significantly higher than those occurring after non-intracranial injuries.
Objectives: The aim of this study was to explore the involved pathophysiological processes and develop biomarkers of trichloroethylene-induced hypersensitivity dermatitis (THD). Methods: We examined the impact of THD on the serum proteome in 8 male patients by comparing the serum samples between acute and healed stages. Sample pooling and immunodepletion were applied for sample preparation. Two-dimensional gel electrophoresis coupled with matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-TOF/MS) was utilized to identify and quantitate differentially expressed proteins. Changes in selected proteins were further confirmed by an ELISA assay. Results: A total of 41 spots were quantitated with significant alteration (p<0.05; fold-change≥± 3.0) in the serum between the acute and healed stages. Of these proteins, 26 proteins were identified by MALDI-TOF-TOF/MS. The identified proteins could be categorized into diverse functional classes, e.g., immunity and defense response, vitamin and lipid transport, fatty acid biosynthesis, actin binding, proteolysis and glycolysis. The ELISA assay confirmed the relative upregulation of calprotectin (S100A8/A9) and downregulation of retinol binding protein (RBP4) in the serum of the acute stage. The alteration of calprotectin and RBP4 was found to be specific to THD rather than trichloroethylene exposure. Conclusions: The pathophysiological processes underlying THD may involve elevated inflammatory responses and oxidative stress, inhibition of vitamin transport, depression of fatty acid biosynthesis, loss of extracellular actin scavenger, increase in oxygen transport, dysfunction in lipid transport, proteolysis and glycolysis. The combination of higher calprotectin and lower RBP4 levels in the serum could be used as potential biomarkers of THD.
Objective: The aim of this study was to compare the noise attenuation (NA) properties of earplugs by using the headphone-based real-ear-attenuation-at-threshold (hREAT) and field microphone-in-real-ear (F-MIRE) techniques. Methods: The subjects were 89 male workers (mean age: 44.8 ± 12.1 yr) exposed to noise above 85 dBA (mean noise exposure period: 14.3 ± 11.3 yr) in a Japanese nonferrous metal manufacturing plant. They were confirmed to have pure-tone air-conduction hearing threshold levels (HTLs). The hREAT and F-MIRE NA values were measured by a Rion AG-20A and a 3M E-A-Rfit, respectively. Results: The NA values could not be measured by hREAT for four workers (hREAT-group). The mean NA of the earplugs for subjects for whom hREAT measurements were possible (hREAT+ group) was 26.0 ± 10.0 dB. The NA of the earplugs could be measured for all subjects using F-MIRE, and the NAs of the hREAT– and hREAT+ groups were 9.5 ± 8.7 and 21.0 ± 7.3 dB. The mean HTL value at 500 Hz to 2 kHz was 45.8 ± 3.1 dB for the hREAT– group, which was significantly lower than the value for the hREAT+ group, 18.0 ± 8.6 dB. Conclusion: Because there is a difference between the NA values obtained by hREAT and F-MIRE, it may be necessary to compensate for this difference. In addition, workers with hearing loss and the length of the measurement time need to be taken into consideration. Finally the F-MIRE method may be useful for educating workers about using earplugs in noisy workplaces.
Objectives: The objectives of this study were to evaluate manganese (Mn)-containing welding fumes' exposure, assess urinary Mn as a biomarker for Mn exposure and investigate the correlation of Mn in air, total fumes and urinary Mn with pulmonary function indices in 118 welders and 37 unexposed controls from two regions in Iran, Assaluyeh and Borujen. Methods: Air samples were collected on mixed cellulose ester membrane filters in personal air samplers and then analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES) (NIOSH Method 7300). For all participants, urine samples were collected during the entire work shift, and Mn in urine was determined by graphite furnace atomic absorption spectroscopy according to NIOSH Method 8310. Spirometric measurements were also done for participants. Results: The maximum exposures to airborne Mn and total fumes were 0.304 ± 0.256 mg/m3 and 21.52 ± 9.40 mg/m3, respectively. The urine Mn levels in the various groups ranged between 0.77 to 7.58 μg/l. The correlation between airborne Mn and urinary Mn was significant for total whole participants. Some values of spirometric indices were statistically lower in welders rather than controls. Conclusions: Our results indicate that many welders have been exposed to higher concentrations of Mn-containing welding fumes. Urinary Mn can be used as a biomarker for Mn exposure. There were weak inverse correlations between Mn-containing welding fumes and pulmonary function indices, and the inverse correlation between urinary Mn with forced vital capacities (FVC) and forced expiratory volume in 1 s (FEV1) was significant.
Objectives: This study investigated physical, psychological and social job characteristics as potential risk factors for complaints of the arms, neck and shoulders (CANS) and mediating effects of muscular tension and need for recovery. Methods: Data were collected among 105 computer workers using questionnaires and electromyography (EMG), and were analyzed with linear regression analyses. Results: Task interdependence, information processing and lower social support predicted more CANS. Physical job demands had no predictive power over and above psychological and social Stressors. Both muscular tension and need for recovery partially mediated the job characteristics—CANS relationships. Conclusions: Occupational health professionals should not neglect psychological and social job characteristics as potentially important predictors of CANS in specific occupational groups, such as office workers. Our findings imply that CANS interventions should not be restricted to ergonomic improvements, but should be accompanied by improvement of the job design from a psychological and social perspective and reactive intervention aimed at decreasing short-term physical strain (muscular tension) and mental strain (need for recovery).
Objective: We evaluated the possible effects of reduced illumination in the workplace on insomnia among office workers. Methods: Seventy-two office workers answered the Athens Insomnia Scale (AIS) in July 2009 (under ordinary illumination, 01 conditions) and July 2010 (under reduced illumination, Rl conditions). The workers were divided into three groups, indoor workers (IWs), semi-outdoor workers (SWs) and outdoor workers (OWs), according to the frequency of working outside of the office because a worker with a high frequency of working outside of the office might rarely be exposed to the lighting condition within an office. The first five items of the AIS (AIS-5) were used to assess sleep difficulties, and the last three items (AIS-3) assessed next-day consequences of sleep or daytime symptoms, which often result from insomnia and/or sleep disorders. Results: Illuminance levels at a height of 1,100 mm from the floor under the Rl conditions (550–490 lux) were significantly lower than under the Ol conditions (750–700 lux). The AIS-5 score of the IWs was significantly increased under the Rl conditions compared with the Ol conditions. There was no difference in AIS-3 scores between conditions for any group. Conclusion: Indoor workers hardly went outside of the office and were exposed only to office light during the daytime. Thus, the underexposure to light could have had an impact on insomnia in those individuals. A novel lighting environment is required to optimize work-related levels of light exposure.
Objectives: The aim of this report is to describe a measles cluster involving health-care workers (HWCs) that occurred in a teaching hospital in central Italy during winter 2011 and the efforts made to promptly identify all the susceptible contacts in order to stop, as soon as possible, transmission of the infection within the hospital. Methods: An epidemiological investigation took place. The immunization status of all the exposed individuals was assessed by personal interviews (history of measles or measles vaccine). Serologie screening for personnel not immune to measles was performed. Results: Four cases of measles infection in HCWs were identified; of the 72 HCWs tested for measles immunity, 50 reported a past history of measles, while 22 underwent serological screening, which showed that all were IgG positive except for one case, which was excluded from duty as recommended. Strict adherence to use of alcohol-based hand rub and rapid implementation of appropriate isolation precautions are essential but insufficient to prevent measles outbreaks in hospital settings. Vaccination is the only reliable protection against nosocomial spread of measles. Therefore, assessing the immunization status of HCW and implementing vaccination strategies are needed in order to virtually set to zero the risk of acquiring and spreading measles in healthcare settings.
Objectives: The purpose of this research was to develop a simultaneous determination method for monoethanol-amine (MEA) and diethanolamine (DEA) in workplace air for risk assessment. Methods: The characteristics of the proposed method, such as recovery, quantitation limit, reproducibility and storage stability of the samples, were examined. Results: An air sampling cassette containing two sulfuric acid-treated glass fiber filters was chosen as the sampler. The MEA and DEA were extracted from the sampler filters, derivatized with 9-fluorenylmethyloxycarbonyl chloride and then analyzed by a high-performance liquid Chromatograph equipped with a fluorescence detector or photo-diode array detector. The overall recoveries from spiked samplers were 86–99 and 88–99% for MEA and DEA, respectively. The recovery after 5 days of storage in a refrigerator exceeded 95%. The overall limits of quantitation were 0.750 and 0.100 jug/sample for MEA and DEA, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.3–1.6 and 0.4–5.7% for MEA and DEA, respectively. Conclusions: The proposed method enables 4-h personal exposure monitoring of MEA and DEA at concentrations equaling 1/3,000–2 times the threshold limit value-time-weighted average (TLV-TWA: 3 ppmfor MEA, 1 mg/m3 for DEA) adopted by the American Conference of Governmental Industrial Hygienists and also by the Japan Society for Occupational Health. The method is useful for estimating worker exposure to MEA and DEA.
Objectives: We report on a patient presenting with an isolated polyneuropathy mimicking Guillain-Barré syndrome (GBS) associated with arsenic exposure. Case: A 43-year-old man visited our emergency room complaining of progressive quadriparesis over the prior 5 days. His clinical course with laboratory data was typical of GBS. However, because of his recent use of herbal medication, we screened for the presence of several heavy metals. Serial analyses of urinary inorganic arsenic concentrations confirmed exposure to arsenic. He was diagnosed as arsenic neuropathy mimicking GBS without any systemic manifestation of arsenic intoxication. Conclusions: The present case study emphasizes the need to consider arsenic intoxication in patients presenting with acute demyelinating neuropathies and histories of herbal medication use.