This study analyzed the trend of construction accidents focused on the small-scale construction sites and the correlation between the ratios of official inspection by government and total fatality injuries per 10,000 people (TFR) by construction size in Korea. The method is to analyze statistical data for the construction accidents and official safety inspection system. In construction, accidents rate and TFR are recently increasing unlike other industries. In addition, the smaller the scale of construction sites, the higher the TFR, and vice versa. The smaller the scale of construction sites, the greater the degree of difference in the TFR for each year, and vice versa. In small-scale construction sites, which have amounted less than $273,000 (£231,000), approximately 45.7% of deaths occurred on sites between $36,400 (£30,800) and $182,000 (£154,000). The ratio of inspection, which represents the ratio of official inspection proportion to site share, is in inverse proportion to the TFR by construction size. As the ratio approached zero, TFR became higher, and the higher the ratio, the lower TFR since the official inspection was mainly carried out in medium and large-scale construction sites. To get an effect of official inspection, the focus of official inspection should move onto the small-scale construction site.
In February 2012, a serious accident which resulted in five fatalities happened during a TBM-tunnel construction under the seabed in Japan. The cause of the accident appeared to be due to the Key-segment slipping out of the segment ring by the thrusting tailskin (wire brushes) of the TBM into the segment ring. This resulted in the collapse of the rings, causing the seabed ground and seawater to flow into the tunnel. We investigated how thin and thick segments without any circumferential joints behave under isotropic and anisotropic pressures using small-scale physical model. In the model tests, pressures were applied to the surroundings of the segment rings and the strains at each segment were measured in order to evaluate the damage. In addition, cases where lubrication on the contact area between the K- and B-segments was present or not were investigated and their discrete element simulations were also conducted.
The charge elimination method for moving charged objects was investigated using a passive type ionizer with an air assist to effectively eliminate the static charge generated at high speed by the roll-to-roll process. The passive ionizer has a grounded needle placed horizontally with respect to the moving charged roll and an air hole to eject an air flow to transport the ions from the grounded needle. The passive ionizer releases ions from the grounded needle electrode when the electric field at the tip of the grounded needle exceeds the corona inception condition. The experimental set up is composed of a moving charged roll, the passive ionizer and surface voltmeters for evaluating performance. The charge elimination current Ie, which corresponds to the amount of ions produced per second was measured for various movement speeds and charge potentials of the charged roll. Supply of the air flow beneath the needle electrode increased Ie because the ions were effectively transported to a place where the charge elimination of the roll did not affect the corona onset condition. The difference in charge elimination performance between the proposed ionizer and a commercial active ionizer was clarified in terms of Ie and the charge elimination rate.
Prolonged standing can cause discomfort on the body of the workers and can lead to injury and occupational disease. One of the ergonomic intervention is through improving the work-rest scheduling. The purpose of this study are to identify the fatigue level from the perception of the worker and to investigate the impact of the work-rest scheduling to the standing workers for 12 h working time with a different gender. This study involved two methods which are self-assessment of the worker and direct measurement by using electromyography (EMG). For self-assessment, 80 workers have been interviewed using questionnaire in order to identify the fatigue level. For direct measurement, EMG was attached to the 15 selected workers at their respective leg and lower back to analyse the muscle efforts. In terms of perception, the results show the discomfort and fatigue level at the lower body region in the following order as foot ankle, lower back and leg. There is a significant difference between gender on discomfort pain for foot ankle and leg. The results show short frequent break by 10 min can reduce the fatigue at the leg and infrequent long break is preferable in order to reduce the fatigue at the lower back. In conclusion, it was found that prolonged standing affect the muscle fatigue and discomfort especially lower extremities such as foot ankle, lower back and leg. Besides that, different type of work rest scheduling and gender have significant result towards the muscle fatigue development.
The aim of this systematic review was to explore studies regarding association between occupational stress and heart rate variability (HRV) during work. We searched PubMed, Web of Science, Scopus, Cinahl and PsycINFO for peer-reviewed articles published in English between January 2005 and September 2017. A total of 10 articles met the inclusion criteria. The included articles were analyzed in terms of study design, study population, assessment of occupational stress and HRV, and the study limitations. Among the studies there were cross-sectional (n=9) studies and one longitudinal study design. Sample size varied from 19 to 653 participants and both females and males were included. The most common assessment methods of occupational stress were the Job Content Questionnaire (JCQ) and the Effort-Reward Imbalance (ERI) questionnaire. HRV was assessed using 24 h or longer Holter ECG or HR monitoring and analyzed mostly using standard time-domain and frequency-domain parameters. The main finding was that heightened occupational stress was found associated with lowered HRV, specifically with reduced parasympathetic activation. Reduced parasympathetic activation was seen as decreases in RMSSD and HF power, and increase in LF/HF ratio. The assessment and analysis methods of occupational stress and HRV were diverse.
Shift workers are at risk for developing serious health issues due to short sleep. One cause of short sleep is circadian misalignment: sleep time is not synchronized with the body’s natural circadian rhythms. Although circadian rhythms are strongly driven by the light/dark cycle, humans have individualized sleep time preferences (chronotypes) based on genetics, development, and external influences. Evening chronotype individuals fall asleep later than average and have a higher risk for developing various noncommunicable diseases. What is unclear is the association between chronotype, shift work, and risks for acquiring chronic conditions. This review is focused on shift worker chronotype and associations with obesity. Because of the paucity of research, other health issues connected with circadian misalignment were included, allowing for a total of 21 research studies. Evidence from this review supports chronotype and certain health issues are associated with shift work, even after adjusting for short sleep duration. In addition, there is evidence to support future research on how shift worker chronotype matched with shift timing impacts worker health. Through better understanding of this interface, occupational health providers can provide more comprehensive worker education on the risks associated with shift work and sleep disturbances.
Emotional exhaustion and innovation at work are two major topics of interest to organization researchers, employees and employers. However, working conditions that foster innovation may also heighten employees’ emotional exhaustion. By conducting a two-wave, longitudinal online study among the German working population (N=320), we analyzed the longitudinal impact of qualitative overload, unreasonable tasks, social support from a supervisor, and task variety on emotional exhaustion and innovation based on the categorization approach from the job demands-resources model research. Longitudinal structural equation modeling revealed that unreasonable tasks predicted emotional exhaustion (γ=0.111, p<0.01) and that task variety predicted individual innovation (γ=0.126, p<0.01) over time. Social support from a supervisor and qualitative overload, however, did not have any longitudinal influence on either emotional exhaustion or individual innovation. Rather unexpectedly, and in contrast to our hypotheses, no diverging effects from working conditions on emotional exhaustion or innovation could be found. The results demonstrate that the presence of unreasonable tasks impairs employees’ psychological well-being and that a high task variety at work leads to innovation. Implications for practice and future studies are discussed.
The aim of this study was to examine whether the presence of untreated caries is different across occupational status among Japanese adults. This was a cross-sectional survey of 1,342 individuals (990 males and 352 females) aged 40–64 yr who underwent medical and dental checkups at a healthcare center in 2011. Oral examination was performed by a dentist and the presence of untreated caries was defined as having at least one untreated decayed tooth. Data regarding current occupational status were obtained using a self-administered questionnaire; the participants were classified into five groups: professionals and managers, clerical and related workers, service and salespersons, agricultural, forestry, and fishery workers, and homemakers and unemployed. Gender-specific odds ratios (ORs) and 95% confidence intervals (CIs) of occupational status for the presence of untreated caries were estimated using logistic regression. After adjusting for potential confounders, female professionals and managers (OR=3.51, 95% CI=1.04–11.87) and service and salespersons (OR=5.29, 95% CI=1.39–20.11) had greater risks of the presence of untreated caries than female homemakers and unemployed. However, this tendency was not observed among males. In conclusion, there was a significant difference in risk of the presence of untreated caries by occupational status among females.
Hand-arm vibration (HAV) from hand-held vibrating machines increases the risk of injury in the form of vasoconstriction in the fingers, commonly named as vibration induced white fingers (VWF). Cold temperature may increase that risk. This experimental study examined and compared the effects of the skin temperature of the hands during and after exposure to HAV in thermoneutral and cold conditions. Fourteen subjects were exposed to three conditions: 25°C with HAV, 5°C with HAV or 5°C without HAV. Their skin temperatures were continuously recorded for the thumbs, index fingers, palms, and back of hands. After 20 min of acclimatization, the subjects held, for five min, two handles where the right handle could vibrate at 5 m/s2 and the left was stationary. Finally, they released their grip and stood still for 10 more min. HAV had no additional cooling effect in cold during gripping of the handles. After the subjects released the handles there was only a HAV-induced cooling effect in the left palm with on average 0.5°C colder skin temperature. A single exposure to HAV will not cause an injury such as VWF, but as the present study show: short-term exposure to HAV causes some changes in skin temperature.
This study quantitatively assessed personal exposure of 86 workers to indium compounds as total dust at 11 Japanese indium plants. The personal exposures to indium concentrations in the breathing zone during an 8 h work-shift were determined by ICP-MS. The arithmetic mean indium concentration of all the workers was 0.098 mg Indium (In)/m3, with individual values ranging from 0.0001 to 1.421 mg In/m3. There were 11 workers whose exposure to indium concentrations exceeded the American Conference of Governmental Industrial Hygienists’ Threshold Limit Value-Time Weighted Average (TLV-TWA) of 0.1 mg In/m3. Based on the condition TLV-TWA<X95 (upper 95th percentile of log-normal distribution), five indium plants were judged as “control measures required”, while 3 other plants were evaluated as “control measures not required”. Five workers belonging to the worst group were exposed to far higher indium concentrations than the TLV-TWA. Another group of 5 workers belonging to the best group was exposed to far lower indium concentrations than the TLV-TWA, and this was attributed to the stringent engineering control measures used at their workplaces. The quantitative assessment of occupational exposure to indium dust was influenced by different occupational exposure limit values without carcinogenicity and particle size-selectivity of indium particulates or “total” dust.
1,2-Dichloropropane (1,2-DCP) is used widely in Korea as a substitute for trichloroethylene or methylene chloride. Some companies mistakenly consider that 1,2-DCP is an eco-friendly detergent because its use is not regulated, but 1,2-DCP is known to inhibit the central nervous system in animals; a few cases of accidental exposure have been reported in humans. We present a case of acute encephalopathy caused by exposure to 1,2-DCP. A 41 yr-old male presented with dizziness, headache, and diplopia after exposure to the detergent without protective equipment. Brain magnetic resonance imaging suggested metabolic encephalopathy, but the patient had no thiamine deficiency and no other metabolic disorder. As the symptoms had commenced after exposure to a large amount of solvent while skimming rust from the surface, and as the symptoms were more severe during the work week, improved on weekends, and disappeared after solvent exposure ceased, the toxic encephalopathy was likely induced by inhalation of the detergent.
In 2012, there were about 2.3 million deaths worldwide attributed to work. The highest workplace fatality rate (WFR) was reported on construction sites due to high risk activities. Globally, fall from height is the leading cause of fatal injuries for construction workers. The objectives are to determine Brunei Darussalam’s demographic distribution of occupational fatality; identify causal agents and industry where occupational fatalities commonly occur; and determine WFR by year. This cross-sectional study retrospectively reviewed records of occupational fatality which were notified to the Occupational Health Division, Ministry of Health, from January 2012 until December 2016. Notified occupational fatalities in Brunei over a five-year period was 50. Most of the cases were in 31–40 age group. 38% of fatality cases occurred in Indonesian workers. 60% were from the Construction industry. 38% were due to fall from height. WFR averaged 5.28 and the highest industry-specific fatality rate was seen in the Construction industry, ranging from 27.94 to 56.45 per 100,000 workers. WFR for Brunei Darussalam from 2012 to 2016 was similar to that of Malaysia, but higher than Singapore and the UK. Industry-specific fatality rate for the Construction and Manufacturing industries were higher than those of Singapore and the UK.