Cooling suits, physiological response, and task performance in hot environments for the power industry.

Heat stress on workers working outdoors in the power industry may result in fatigue and deterioration in task performance. This research collected and analyzed data on task performance of workers working indoors and outdoors with and without a cooling suit. The task performance was compared on the basis of heart rate, oxygen consumption, tympanic temperature, subjective responses, productivity, and error rates. Based on One-Way Analysis Of Variance (ANOVA) results, a significantly lower estimated working oxygen consumption was observed (p < .001) when the cooling suit was worn. The productivity was higher while workers wore the cooling suit as compared to no cooling suit (p = .011) whereas the error rates were significantly lower (p < .001). Also a significantly lower self-reported discomfort was observed in the neck and shoulders while working wearing the cooling suit (p = .004). This study concluded that wearing a cooling suit while working outdoors was associated with physiological benefits as well as improved task performance of the study participants.     

The effects of chemical protective suits on human performance

Workers in the chemical industry are often required to wear protective suits while performing tasks. While these suits can be life saving, they increase the difficulty and discomfort faced by the wearer. This research explores the performance of individuals wearing the highly cumbersome Level A suit. The suits are heat-retentive and can cause fatigue that affects performance by increasing response time and decreasing accuracy. Members of Missouri’s Civil Support Team (CST) served as subjects for this research. They conducted fine and gross motor tests. Their completion time and accuracy were evaluated both out-of-suit and in-suit for the Level A chemical protective suits.A t-test was conducted to evaluate the effect of the Level A suits on performance. Results showed a significant increase in completion time and errors for gross motor tasks. This type of task had up to a 103% increase in time required and up to a 34% decrease in accuracy. The suit’s impact on fine motor skill was also significant, but to a lesser extent. Repeated measures test was performed to evaluate any potential time-in-suit effect. A decrease in mean task completion time was observed for some of the tasks. There was a corresponding decrease in accuracy but no consistent time-in-suit effect was identified.The results indicate the need for care when designing procedures and equipement to be used by humans wearing restrictive PPE. It is important to take human limitations into consideration in the design phase in order to decrease the need for human adaptation and increase system safety. To achieve this, understanding human factors is imperative when designing equipment, tasks, or procedures for workers wearing PPE.     

Combined Effects of Physical Demands and Shift Working on Low Back Disorders Among Nursing Personnel

The aim of this study was to investigate the synergistic effects of physical demands and shift working on low back disorders (LBDs) among nursing personnel. The study used 2 questionnaires: a self-administered questionnaire composed of parts of Nordic musculoskeletal questionnaire to assess LBDs and job content questionnaire to assess physical demands. The participants were divided into 4 groups: from group 1 (low physical demands day workers) to group 4 (high physical demands shift workers). In regression analysis, high physical demands were associated with the prevalence of LBDs independently (OR 4.4, 95% CI [2.40, 8.00] and p < .05), but there was no association between shift working and LBDs (p > .05). Odds ratio in high physical demands shift workers was 9.33 compared to the reference group (p < .001). Calculated synergistic index was 7.37. Simultaneous impacts of shift working and high physical demands may increase the prevalence of LBDs among nursing personnel.     

Physiological evaluation of chemical protective suit systems (CPSS) in hot conditions.

This job-related experiment investigated physiological strain in subjects wearing impermeable chemical protective suit systems (CPSSs) weighing about 28 kg. Two types of CPSSs were studied: the self-contained breathing apparatus was carried either inside or outside the suit. Eight healthy and physically fit male firefighter instructors aged 32 to 45 years volunteered for the study. The test drill, performed at a dry, windless ta of 40 degrees C, was divided into 2 consecutive work sessions of 14.5 min (a 20-min rest between) including typical operational work tasks. Considerable thermal and maximal cardiovascular strain and intense subjective discomfort measured in the firefighters emphasize the need to limit working time in hot conditions to only 10-12 min while wearing CPSSs. The present results indicate that the exceptionally heavy physical load and psychological stress during operations in chemical emergencies must be considered in the assessment of the cardiovascular capacity of ageing firefighters using CPSSs.     

Effects of carrying handles,postures, materials and distances on carrying capability

This study recruited 14 industrial workers to examine the effects of carrying handles, postures, materials and distances on maximum acceptable weights of carrying (MAWC), and resulting heart rate and body rating of perceived exertion (RPE) for a 20 min intensive carrying task. This study showed that MAWC of carrying with bar handles, carrying with hands-and-body posture, solid materials and 4?m distance were significantly higher than that of carrying with groove handles, carrying with hands posture, liquid materials and 8?m distance, respectively. The resulting heart rates while carrying MAWCs of groove handles, hands-and-body carrying posture, solid materials and 4?m distance were lower than the resulting heart rates while carrying MAWCs of bar handles, hands carrying posture, liquid materials and 8?m distance, respectively. Most pair levels of independent variables resulted in similar body's RPEs except for the pair levels of carrying distance.     

A ventilation cooling shirt worn during office work in a hot climate: cool or not?

The aim of the study was to identify whether a ventilation cooling shirt was effective in reducing heat strain in a hot climate. Eight female volunteers were exposed to heat (38?°C, 45% relative humidity) for 2?h with simulated office work. In the first hour they were in normal summer clothes (total thermal insulation 0.8?clo); in the second hour a ventilation cooling shirt was worn on top. After the shirt was introduced for 1?h, the skin temperatures at the scapula and the chest were significantly reduced (p?<?0.05). The mean skin and core temperatures were not reduced. The subjects felt cooler and more comfortable by wearing the shirt, but the cooling effect was most conspicuous only during the initial 10?min. The cooling efficiency of the ventilation shirt was not very effective under the low physical activity in this hot climate.     

Respiratory Impairment in Cotton-Ginning Workers Exposed to Cotton Dust

Dust generated during the handling and processing of cotton causes ill health of ginning workers. The purpose of this study was to determine the prevalence of respiratory symptoms among cotton-ginning workers. This study involved 188 workers of 10 cotton-ginning factories. Forced vital capacity (FVC), peak expiratory flow rate (PEFR), and forced expiratory volume in 1 s (FEV1) declined significantly with increasing duration of exposure (p < .001) of the cotton-ginning workers. Results of a standard respirator medical evaluation questionnaire indicated that, depending on duration of exposure, 51%–71% of cotton-ginning workers suffered from chest tightness, 55%–62% experienced chest pain, while 33%–42% of the workers reported frequent cough. Blood tests of the workers showed higher values of erythrocyte sedimentation rate, eosinophils, and white blood cells when exposure was longer. Byssinosis symptoms were observed among the workers. We recommend regular periodical medical check-ups, compulsory use of personal protective equipment, and proper ventilation at the workplace.     

Prediction of Duration Limited Exposure for Participants Wearing Chemical Protective Clothing in the Cold

The suitability of the IREQ (insulation required) index for predicting the thermal responses of 6 participants wearing chemical protective clothing was tested during exercise at -20 and -25 °C. IREQ was used to calculate duration limited exposure (DLE). Measured DLE correlated (r= .899, p < .001) with the predicted DLE. In exposures exceeding 40 min, however, the predicted DLE tended to be 10-20 min too short compared to the measured one. During short exposures the prediction was 5-20 min too long. The results show that IREQ overestimated the cold strain in participants wearing chemical protective clothing during cold exposures longer than 40 min. Nevertheless, predicted DLE never exceeded measured times and thus the prediction was always safe from the occupational point of view.     

Occupational noise exposure and hearing defects among sawmill workers in the south of Thailand

The aim of this study was to investigate occupational noise exposure and hearing defects among sawmill workers in the south of Thailand. Seven hundred sawmill workers participated, of which 335 (47.9%) were male. The mean age of the sawmill workers was 33.5 years (SD 10.2), and more than 60% were <35 years old; 75.1% of the workers had less than 5 years of work experience. Only about one in four workers (25%) had been trained in use of personal protective equipment (PPE), and half of the participants never or rarely wore PPE while working. The prevalence rate of noise-induced hearing loss (NIHL) was 22.8% (N?=?42). Male workers had significantly higher risk than female workers (odds ratio [OR]?=?2.21). Workers aged older than 25 years had significantly higher risks for NIHL (OR?=?3.51–12.42) than workers younger than 25 years. Sawing workers had higher risk for NIHL than office workers (OR?=?3.07).     

Evaluating the effectiveness of a logger safety training program

INTRODUCTION: Logger safety training programs are rarely, if ever, evaluated as to their effectiveness in reducing injuries. METHOD: Workers' compensation claim rates were used to evaluate the effectiveness of a logger safety training program, the West Virginia Loggers' Safety Initiative (LSI). RESULTS: There was no claim rate decline detected in the majority (67%) of companies that participated in all 4 years of the LSI. Furthermore, their rate did not differ from the rest of the WV logging industry that did not participate in the LSI. Worker turnover was significantly related to claim rates; companies with higher turnover of employees had higher claim rates. Companies using feller bunchers to harvest trees at least part of the time had a significantly lower claim rate than companies not using them. Companies that had more inspections per year had lower claim rates. CONCLUSIONS: High injury rates persist even in companies that receive safety training; high employee turnover may affect the efficacy of training programs. The logging industry should be encouraged to facilitate the mechanization of logging tasks, to address barriers to employee retention, and to increase the number of in-the-field performance monitoring inspections. Impact on industry There are many states whose logger safety programs include only about 4-8 hours of safe work practices training. These states may look to West Virginia's expanded training program (the LSI) as a model for their own programs. However, the LSI training may not be reaching loggers due to the delay in administering training to new employees and high levels of employee turnover. Regardless of training status, loggers' claim rates decline significantly the longer they work for a company. It may be that high injury rates in the state of West Virginia would be best addressed by finding ways to encourage and facilitate companies to become more mechanized in their harvesting practices, and to increase employee tenure. Increasing the number of yearly performance inspections may also be a venue to reduce claim rates. Future research could investigate in better detail the working conditions of West Virginia loggers and identify barriers to job tenure, particularly for workers whose primary job task is chainsaw operation. A larger-scale study of the effect of performance monitoring inspections on claim rates is also warranted.     

Electromyographic analysis of relevant muscle groups during completion of computer tasks using different computer mouse positions

Background. We analyzed muscular activity for different computer mouse positions during the completion of a timed computer task and determined whether the different mouse positions could affect muscular activity, productivity and perceived fatigue. Methods. The subjects were nine healthy young men. Two mouse positions were studied: the distal position (DP), with the forearm rested on the desk; the proximal position (PP), with only the wrist rested on the desk. The subjects performed a 16-min task in each position. Surface electromyography data were recorded for the upper back and shoulder muscles. Work productivity and muscular activity were measured for each mouse position. A visual analog scale was used to assess subjective fatigue. Results. Muscular activity was higher in muscle (m.) deltoideus (posterior) for the DP, while it was significantly higher in m. inferior infraspinatus for the PP. The visual analog scale score was significantly higher and work productivity was lower in the PP. Conclusions. We found that using a mouse in the DP rather than the PP leads to less activity of the external rotators, less perceived fatigue and more productivity. This suggests that the DP is preferable to the PP for computer work involving a mouse.     

The interactive relationship of competitive climate and trait competitiveness with workplace attitudes,stress, and performance

There has been a considerable debate about the individual and organizational benefits of competition. Adopting a person–environment fit perspective, this research examined the influence of competition as an interaction between trait competitiveness and competitive climate. Using a sample of information technology workers, competitive climate was considered as both an individual level variable and a workgroup variable. Results show that the effect of competitive climate depended on trait competitiveness and the level at which climate was assessed for four of the outcomes assessed: job satisfaction, organizational commitment, job dedication, and supervisor‐rated task performance. In general, the effect of competitive climate was more negative for individuals lower in trait competitiveness. Competitive psychological climate was associated with greater stress regardless of the level of trait competitiveness but was not directly related to self‐rated task performance. Findings suggest that managers should be cautious in encouraging competitive climate. Copyright © 2007 John Wiley & Sons, Ltd.     

Musculoskeletal Symptoms In Workers

Self-report measures of musculoskeletal discomfort are a widely used and generally accepted risk factor for musculoskeletal disorders in epidemiologic research. The aim of this study was to investigate the prevalence of musculoskeletal symptoms in packing workers. A cross-sectional study of 75 workers was carried out using a modified Nordic questionnaire. Prevalence was determined with the percentage of positive responses to questions on musculoskeletal symptoms. Odds ratios and 95% confidence intervals were the measures of association between prevalent musculoskeletal symptoms and demographic factors; they were determined with logistic regression. Most musculoskeletal symptoms in workers were from the low back (44.0%), shoulders (33.3%) and neck (32.0%). Years worked were strongly significantly associated with musculoskeletal symptoms and pain in the neck, shoulders and wrists/hands, P< .001-.050. Hazards related to repetitive movements and discomfort postures could be reduced with stretching exercises, rotation schedules and through new engineering solutions.     

视觉记忆型次任务对驾驶绩效及安全的影响

为研究视觉记忆型次任务对驾驶绩效及安全的影响,采用对未知内容的记忆任务和对已知内容的再认任务分别表征工作记忆和长时记忆过程,构建多组不同难度的次任务,基于标准换道试验环境LCT进行双任务研究。提取并分析驾驶人执行不同任务时车道保持、换道控制等指标的差异以及次任务绩效,基于主客观数据构建综合评判模型。结果表明:双任务驾驶条件下,车辆平均路径偏差、方向盘平均转向角、车道偏移次数指标增大,正确换道比例减小,感知负荷增大,总绩效下降。困难工作记忆组与简单工作记忆组相比,随着任务难度增大,换道控制绩效下降,感知负荷增大,总绩效下降36.1%;困难再认组与工作记忆组相比,车道保持绩效、换道控制绩效提高,感知负荷下降,总绩效提高50%;简单再认组与工作记忆组相比,总绩效变化不大;困难工作记忆组综合绩效最低。上述结果说明:随着次任务难度增大,总绩效下降,但将对未知内容的工作记忆过程转化为对已知内容的再认过程时,总绩效明显提升,这一特点在任务难度较大时更为显著。     

Effects of Dram Shop,Responsible Beverage Service Training,and State Alcohol Control Laws on Underage Drinking Driver Fatal Crash Ratios

Objectives: In this study, we aimed to determine whether three minimum legal drinking age 21 (MLDA-21) laws—dram shop liability, responsible beverage service (RBS) training, and state control of alcohol sales—have had an impact on underage drinking and driving fatal crashes using annual state-level data, and compared states with strong laws to those with weak laws to examine their effect on beer consumption and fatal crash ratios.

Methods: Using the Fatality Analysis Reporting System, we calculated the ratio of drinking to nondrinking drivers under age 21 involved in fatal crashes as our key outcome measure. We used structural equation modeling to evaluate the three MLDA-21 laws. We controlled for covariates known to impact fatal crashes including: 17 additional MLDA-21 laws; administrative license revocation; blood alcohol concentration limits of.08 and.10 for driving; seat belt laws; sobriety checkpoint frequency; unemployment rates; and vehicle miles traveled. Outcome variables, in addition to the fatal crash ratios of drinking to nondrinking drivers under age 21 included state per capita beer consumption.

Results: Dram shop liability laws were associated with a 2.4% total effect decrease (direct effects: β =.019, p =.018). Similarly, RBS training laws were associated with a 3.6% total effect decrease (direct effect: β =.048, p =.001) in the ratio of drinking to nondrinking drivers under age 21 involved in fatal crashes. There was a significant relationship between dram shop liability law strength and per capita beer consumption, F (4, 1528) = 24.32, p <.001, partial η² =.016, showing states with strong dram shop liability laws (Mean (M) = 1.276) averaging significantly lower per capita beer consumption than states with weak laws (M = 1.340).

Conclusions: Dram shop liability laws and RBS laws were both associated with significantly reduced per capita beer consumption and fatal crash ratios. In practical terms, this means that dram shop liability laws are currently associated with saving an estimated 64 lives in the 45 jurisdictions that currently have the law. If the remaining 6 states adopted the dram shop law, an additional 9 lives could potentially be saved annually. Similarly, RBS training laws are associated with saving an estimated 83 lives in the 37 jurisdictions that currently have the laws. If the remaining 14 states adopted these RBS training laws, we estimate that an additional 28 lives could potentially be saved.     

The Effects of Hearing Protectors on Auditory Localization: Evidence From Audio-Visual Target Acquisitioi

Response times (RT) in an audio-visual target acquisition task were collected from 3 participants while wearing either circumaural earmuffs, foam earplugs, or no hearing protection. Analyses revealed that participants took significantly longer to locate and identify an audio-visual target in both hearing protector conditions than they did in the unoccluded condition, suggesting a disturbance of the cues used by listeners to localize sounds in space. RTs were significantly faster in both hearing protector conditions than in a non-audio control condition, indicating that auditory localization was not completely disrupted. Results are discussed in terms of safety issues involved with wearing hearing protectors in an occupational environment.     

基于深度学习的复杂作业场景下安全帽识别研究

为有效预防由于个人防护缺失所造成的事故,着力探究复杂作业情况下施工人员安全帽佩戴情况的智能化识别.提出在Faster R-CNN目标检测算法的基础上,针对小目标的安全帽识别问题通过增加锚点提升检测能力,为解决数据集中类别不平衡问题采用Focal loss替代原本的损失函数,为解决安全帽预测区域不匹配问题,引入ROI A...     

Hazard perception of stroke drivers in a video-based Japanese hazard perception task

Objective: Hazard perception (HP) is the ability to identify a hazardous situation while driving. Though HP has been well studied among neurologically intact populations, little is known about the HP of neurologically impaired populations (in this study, stroke patients). The purpose of this study is, first, to investigate the HP of stroke patients and, second, to verify the effect of lesion side (right or left hemisphere) on HP, from the viewpoint of hazard types.

Methods: Sixty-seven neurologically intact age-matched older drivers and 63 stroke patients with valid driver’s licenses conducted a video-based Japanese HP task. Participants were asked to indicate the hazardous events in the driving scenario. These events were classified into 3 types: (1) behavioral prediction hazards (BP), which are those where the cause is visible before it becomes a hazard; (2) environmental prediction hazards (EP), which are those where the ultimate hazard may be hidden from view; and (3) dividing and focusing attention hazards (DF), which are those where there is more than one potential hazard to monitor on approach．Participants also took part in the Trail Making Test (TMT) to evaluate visual information processing speed.

Results: The results showed that the number of responses was significantly fewer for stroke patients than for age-matched drivers for all hazard types (P < .001), and this difference was not affected by lesion side (P > .05). It was also found that stroke patients showed a slower response time than age-matched drivers only for BP (P < .001). The lesion side did not affect response latency (P > .05). Results of the TMT revealed that age-matched drivers completed the task significantly faster than stroke patients (P < .001) and that neither TMT-A nor TMT-B differentiated between patients with left hemisphere damage and patients with right hemisphere damage (P > .05).

Conclusions: Firstly, HP in stroke patients is low compared to age-matched drivers. Secondly, even if stroke patients notice hazards, their response may be delayed in a BP situation, due to a slower visual information processing speed. Thirdly, the lesion side does not appear to affect HP.     

Validity and reliability of a job factors questionnaire related to the work tasks of physical therapists

Physical therapists engage in work tasks that expose them to occupational risk factors related to musculoskeletal disorders. Due to the gap in the literature on instruments focused on those workers, this study adapted a job factors questionnaire to physical therapists, and assessed its psychometric properties. The questionnaire was adapted and its content validity was established. The psychometric properties were evaluated among 142 physical therapists. Reliability was verified using the temporal-stability design and internal consistency. Construct validity was assessed with the known-groups technique. Test-retest results demonstrated intraclass correlation coefficients between .82 and .90 (p < .001). Cronbach's α of .91 verified the reliability of the questionnaire. The known-groups technique demonstrated a statistically significant difference on the scores of the items when physical therapists were compared to office workers. The results indicated that the adapted questionnaire had acceptable psychometric properties for assessing problematic job factors among physical therapists working in hospitals.