Work-related problems in metal handling tasks in Bangladesh: obstacles to the development of safety and health measures

Many manual labourers in Bangladesh are involved with metal-handling tasks that are both physically demanding and stressful. The metal workers have been significantly exposed to prolonged hammering and cutting activities in excessive noise and with awkward body postures. Moreover, stressors from heat and humidity, welding fumes and metal dusts often cause excess strain, and are reflected in a deterioration of their physical work performance. Indeed, physical work is the economic source in many developing countries for the support of worker's family and relatives. Unfortunately, there are many obstacles and a lack of efficient steps to restore ergonomics principles as well as occupational safety and health measures. Thus, in this paper, tasks, and jobs are classified and analysed from the results of an ergonomics survey from 343 subjects (293 adults men, age 20-40 years; 17 women, 19-32 years) and 33 child workers (14-17 years). Four types of metal working sites from two districts in Bangladesh were surveyed using questionnaires and interviews. The results showed that a significant number of workers experienced a high prevalence of work-related problems. The main aim was to identify stressful task that are related to musculoskeletal and psychosocial symptoms. Moreover, the findings reveal the possibility of why ergonomics measures are unsuccessful; and if they could have an immediate effect on the safety and health of metal workers in Bangladesh.     

Workers' intrinsic work motivation when job demands are high: The role of need for autonomy and perceived opportunity for blended working

Work overload or work pressure may undermine workers' intrinsic motivation. In the present research, we tested the conditions under which this may (not) occur, including the perceived opportunity to blend on-site and off-site working through the effective use of computers and modern information and communication technology. Our sample consisted of 657 workers (51% female) representing a variety of industries. As hypothesized, it is not high job demands per se, but high demands in combination with a high need for autonomy and a lack of perceived opportunities for blended working that undermines intrinsic work motivation. When workers high in need for autonomy perceived opportunities for blended working, their intrinsic work motivation was not negatively affected by increasing job demands. This main finding suggests that, particularly for workers high in need for autonomy, the perceived opportunity for blended working is an effective, contemporary resource to cope with the increasing job demands typically observed in today's workplace. Theoretically, these findings contribute to the refinement and extension of influential demands-resource models and Person-Job Fit theory. Practically, our findings may show managers how to effectively keep workers intrinsically motivated and productive in their jobs when job demands are high.     

Preventing falls from roofs: a critical review

Work-related falls from roofs remain a significant problem for workers in the construction industry. Knowledge about the main causative or initiating factors leading to fall incidents is desperately needed for fall prevention intervention. From biomechanical and psychophysiological perspectives the majority of occupational falls, including falls from roofs, can be regarded as loss-of-balance incidents. The primary objective of this paper is to summarize the current knowledge from multiple fields about factors that are related to the control of balance during roofing work. An extensive literature review identified a number of environmental, task-related and personal factors that degrade the control of balance and could be associated with the initiation of falls from roofs. These factors include visual exposure to elevation; unstable visual cues and inadequate visual information in the work environment; ‘confined’ and inclined support surfaces; unexpected changes in roof surface properties; load handling; physical exertion; fatigue; task complexity that diverts workers' attention; individual differences; work experience and training; and personal protective equipment. Current measures to reduce falls from roofs focus mainly on fall protection procedures, such as the use of covers, guardrails, safety nets, and personal fall arrest systems, or the application of warning-line systems, safety monitoring systems, and fall protection plans. In many instances, these procedures are not practical for the industry and current regulations allow the use of alternative means of fall protection, such as slide guards. Future research on preventing falls from roofs should consider the main effects and interactions of the environmental, task-related and personal factors that affect the balance control of workers. Research-supported improvements in the visual and physical characteristics of the roof work environment, the construction materials and methods, and work procedures and practices may result in improved workers' balance control as well as overall safety performance, and would ultimately reduce incidents of falling from a roof.     

Evaluation of proper height for squatting stool

Many jobs and activities in people's daily lives have them in squatting postures. Jobs such as housekeeping, farming and welding require various squatting activities. It is speculated that prolonged squatting without any type of supporting stool would gradually and eventually impose musculoskeletal injuries on workers. This study aims to examine the proper height of the stool according to the position of working materials for the squatting worker. A total of 40 male and female college students and 10 female farmers participated in the experiment to find the proper stool height. Student participants were asked to sit and work in three different positions: floor level of 50 mm; ankle level of 200 mm; and knee level of 400 mm. They were then provided with stools of various heights and asked to maintain a squatting work posture. For each working position, they were asked to write down their thoughts on a preferred stool height. A Likert summated rating method as well as pairwise ranking test was applied to evaluate user preference for provided stools under conditions of different working positions. Under a similar experimental procedure, female farmers were asked to indicate their body part discomfort (BPD) on a body chart before and after performing the work. Statistical analysis showed that comparable results were found from both evaluation measures. When working position is below 50 mm, the proper stool height is 100 or should not be higher than 150 mm. When working position is 200 mm, the proper stool height is 150 mm. When working position is 400 mm, the proper stool height is 200 mm. Thus, it is strongly recommended to use proper height of stools with corresponding working position. Moreover, a wearable chair prototype was designed so that workers in a squatting posture do not have to carry and move the stool from one place to another. This stool should ultimately help to relieve physical stress and hence promote the health of squatting workers. This study sought to evaluate and make suggestions on user preference and BPD of proper stool height, at which work can be done comfortably, according to squatting work position. In short, results showed that proper stool height differed according to working position, even with similar squatting tasks.     

The association between shift work and treatment-seeking migraine in Denmark

Abstract

In Europe, the one-year prevalence of migraine is 14.9% and migraine is on the top-10 list of leading causes of years lost to disability. Sleep disturbances and irregular daily routines are considered triggers of migraine and these factors are well-known consequences of shift work. We studied the association between treatment-seeking migraine and shift work, categorised as fixed evening work, fixed night work and variable working hours with and without night work in a Danish working population of 5872 participants. When compared with fixed day workers, only participants with fixed evening work were found to have significantly increased odds of reporting treatment-seeking migraine after adjustment for socio-demographic and behavioural covariates (OR = 1.56; 95% CI 1.05–2.32). Participants with seniority of 10 years or more notably accounted for this association. Due to the cross-sectional design, selection mechanisms may have biased the results.

Practitioner Summary: The study showed higher odds of treatment-seeking migraine among evening workers even when taking a range of potential confounders into account. Due to the cross-sectional design, we cannot draw any causal inferences, but potential mechanisms underlying the present study are discussed, with an emphasis on possible selection into evening work.     

Effect of Job Rotation Types on Productivity,Accident Rate,and Satisfaction in the Automotive Assembly Line Workers

This study investigates different autonomous job rotation types to analyze their impacts on productivity, accident rate, and worker's satisfaction. The subjects of research were 422 assembly‐line units in 3 production plants from an automobile company. The preferred rotation types and workers’ satisfaction scores in the 422 units were surveyed by the average worker's experience and work productivity, quality and accident rate scores were traced over a 5‐year period. Results showed that workers with little work experience preferred to work in shorter cycles composed of a small variety of tasks, whereas workers with more experience preferred longer cycles composed of a larger variety of tasks. In addition, autonomously chosen rotation systems proved to boost productivity and work satisfaction when compared to units that did not implement job rotation. In contrast, only 4 out of 10 rotation types showed improvements in decreased number of accidents. Of the 10 rotation types, ones with daily cycles with a small range of tasks and weekly cycles with a wide range of tasks displayed the most promising results for productivity, work satisfaction, and accident prevention. This study implies that the preferred types of rotation do not necessarily lead to higher productivity, safety, and satisfaction. The results of this study are expected to serve as a basic guideline for job design.     

Objective Workload and Behavioural Response in Airport Radar Control Rooms

Previous research indicated that peak traffic and the duration of radio-communications were good predictors of behavioural response of air traffic controllers working in air route traffic control centres. In this study we investigated if these two measures of workload were generalisable to controllers (ATCs) working in radar facilities serving major airports. 3,110 observations were made on radar sectors at the 13 major radar control rooms in the U.S.A. A large number of air traffic variables and communication tasks were measured. Behavioural ratings were made by expert-observer ATC's. The results replicated previous findings that peak traffic and the duration of radio-communications functioned as behavioural stressors. Time monitoring and stand-by time also were found to predict behavioural responses. Careful consideration of these and other results led to the conclusion that peak traffic is the most generalisable environmental stressor for ATC's behaviour whereas the other workload measures are more correctly viewed as concomitants of the demand characteristics of ATC work.     

A case study of factor influencing role improvisation in crisis response teams

Common characteristics of crisis situations are ambiguous and unplanned for events. The need for improvised roles can therefore be an imperative factor for the success of an operation. The aim of this study is to deepen the understanding of the processes taking place during improvised work “as it happens”. A case study of a crisis management team at work is presented and provides an in-depth analysis of the information and communication flow of persons acting in improvised roles, including contextual factors influencing the task at hand. The analysis suggests that three main factors lay behind decreased performance by the team when some of its members were forced to take on roles for which they lacked professional training; lack of language skills, lack of domain knowledge and insufficient organizational structure of the tasks. Based on the observations from this case study, we suggest three ways of improving a team’s performance and hence resilience when forced to improvise due to lack of personnel in one or more required competence areas. These are training to take on the responsibility for tasks or roles outside ones professional area of specialization, developing formal routines for changes in roles and tasks and developing and using tools and routines for information sharing.     

How many crowdsourced workers should a requester hire?

Recent years have seen an increased interest in crowdsourcing as a way of obtaining information from a potentially large group of workers at a reduced cost. The crowdsourcing process, as we consider in this paper, is as follows: a requester hires a number of workers to work on a set of similar tasks. After completing the tasks, each worker reports back outputs. The requester then aggregates the reported outputs to obtain aggregate outputs. A crucial question that arises during this process is: how many crowd workers should a requester hire? In this paper, we investigate from an empirical perspective the optimal number of workers a requester should hire when crowdsourcing tasks, with a particular focus on the crowdsourcing platform Amazon Mechanical Turk. Specifically, we report the results of three studies involving different tasks and payment schemes. We find that both the expected error in the aggregate outputs as well as the risk of a poor combination of workers decrease as the number of workers increases. Surprisingly, we find that the optimal number of workers a requester should hire for each task is around 10 to 11, no matter the underlying task and payment scheme. To derive such a result, we employ a principled analysis based on bootstrapping and segmented linear regression. Besides the above result, we also find that overall top-performing workers are more consistent across multiple tasks than other workers. Our results thus contribute to a better understanding of, and provide new insights into, how to design more effective crowdsourcing processes.     

Prevention of accidents and injuries in Brazil

After the Second World War, Brazil went through a process of rapid industrialization: industries increased in size and new factories were built. Agriculture, started to diversify, and hand tools were replaced by machinery. As a result, a large number of new workers were needed. As their work tasks were unfamiliar and their training not good, work accidents and injuries at work increased. Statistical records of industrial accidents were started in 1969 and disclosed that in 1970 nearly 18% of industrial workers suffered accidents. A high proportion led to orthopaedic problems, 74-76% being back problems. Statistics for agricultural workers were not available, but a sample study in the state of Sao Paulo disclosed that 9-22% of workers suffered accidents, 54-65% by those working on sugar cane plantations. Preventive measures imposed by legislation were able to reduce these numbers and in 1984 the percentage of industrial workers suffering accidents fell to 3-84%. Legislation regarding the protection of workers from accidents is discussed and examples of the adopted preventive measures are presented.     

Assessment of duration and frequency of work tasks by telephone interview: reproducibility and validity

Quantitative estimation of physical work load requires breakdown of jobs into smaller entities. The objective was to study the inter-rater reproducibility of the contents, frequency and duration of work tasks assessed by telephone interview. Two researchers interviewed 18 industrial workers with an interval of from 2 to 3 weeks in a balanced and blinded design. Altogether 114 tasks were identified, 68 of which were recorded by both interviewers. The tasks were classified into regularly occurring (n=34) and occasional (n= 80). The outcome was the total duration of the tasks per day computed from the data on frequency and duration. Validity of the interview was studied against prestructured diaries filled in by nine workers. The interviewers' assessments of the overall contents of the tasks were rated as ‘similar’ or ‘very similar’ for 17 of the 18 workers. Both interviewers detected all 34 regularly occurring tasks. The intraclass correlation coefficient (ICC) of the total duration between the interviewers was 0.81 for regularly occurring tasks. ICCs of the total duration between the diary and the two interviewers were 0.90 and 0.91. However, in many cases the workers could not give a numerical value for duration or frequency. A telephone interview can be used as a first step in exposure assessment in epidemiological studies on risk factors of musculoskeletal disorders. These results show that a single telephone interview can give reproducible and valid information of the frequency and duration of tasks occurring daily. For occasional tasks interview methods should be developed further.     

A study of exposure to cold in cold stores

Effects of exposure to cold on skin-temperature and thermal sensations of eight experienced men wearing protective clothing, who were working normally in a cold store at sub-zero temperatures of about -27 degrees C, were studied to assess the feasibility of deriving work recovery routines from experiments conducted in the actual working environment. Although the variations in the responses to cold were such that insistence on a rigid pattern of working and recovery times would be unwise, results indicated that exposures of about 40% of the total time available would not make the risk of discomfort unacceptable, under the usual working conditions provided clothing rated at 5 to 6 togs was worn. Whilst individual reactions are important and there was, for example, an inverse relation between the age of the operative and the time spent in the cold, the results showed that the reactions of the working group are equally important. It was evident that the operatives worked together as a group which appeared to arrange the work loads to suit individual members of the group. The dry-bulb temperature of the air was an adequate index of the thermal environment, which was relatively constant so that the stress upon the operatives was assessed by time spent in the cold. Considerable individual variations in response to cold were evident; the hands and feet were found to be particularly vulnerable areas, and in general a significant fall in skin-temperature occurred whilst the operatives worked inside the store. At some time during the study, all operatives experienced discomfort from cold and there appeared to be a definite association between percentage incidence of discomfort and the time spent in the store. The current practice for the setting of work/recovery routines was questioned and suggestions were made following the results of the investigation.     

A Review of: “The Dictionary of Developmental and Educational Psychology”. Edited by ROM HARRE and ROGER LAMB (Oxford: Black well, 1986.) [Pp. xi + 271.] Price unknown,ISBN 0-631-14604-0.

Preventive measures aimed at minimizing the occurrence of work-related musculoskeletal disorders of the upper limbs (WMSDs) associated with repetitive tasks can be divided into three categories: structural, organizational and educational. Whenever specific risk and injury assessments have shown the need for preventive action, this is most often implemented within the framework of a range of assorted measures. In particular, structural measures involve optimizing the layout of the work area and furnishings, and the 'ergonomic' properties of work tools and equipment. Such measures serve to alleviate the problems caused by the use of excessive force and awkward postures. The authors refer to the principles guiding such structural measures, in the light of the extensive literature that has been published on the subject. Organizational (or reorganizational) measures essentially relate to job design (i.e. distribution of tasks, speeds and pauses). They serve to alleviate problems connected with highly repetitive and frequent actions, excessively lengthy tasks and inadequate recovery periods. Very few relevant findings are available: the authors therefore illustrate in some detail a practical trial conducted in a major engineering firm. The objective was to lower to acceptable limits the frequency of certain repetitive tasks performed using the upper limbs. The trial made it possible to identify a suitable plan and schedule of measures taking into due consideration the impact of the plan on production levels (and costs). The fundamental principles guiding the adoption of specific educational and training programmes for the workers and their supervisors are presented and discussed.     

Using Multimedia to Support Cooperative Editing

By Cooperative Editing we mean the coordinated manipulation of information by a group of authors. During the editing process the (co-)authors need to communicate their ideas, drafts and constraints (remotely or face-to-face) until a final version of the information is achieved. For the different phases of this process - discussion of ideas, editing, cross-checking - different media or media integration are adequate. Furthermore, analysing the transition from individual work to group work, within different human activities, two pitfalls are often detected if computer support is considered: a) technological communication difficulties, especially if the group is remotely located on heterogeneous hardware, associated with a fall in productivity and frequent social inadequacies of the group's computer support; b) the lack of integrated media processing tools available for group editing. In order to solve these problems, we suggest that Multimedia can be applied in two ways: to effectively support the necessary group communication links; and to enhance the expressiveness of the information edited. To test this statement we have been conceptualising and implementing a prototype system. Most of the techniques involved can be used in other tools that need multimedia capabilities or that support other specific types of group activities. The innovative aspects of the work are the use of multimedia techniques to support demanding applications, possibly on cross-platforms, and the integration of several concepts to support cooperation.     

Work routines as an object of resistance during information systems implementations: theoretical foundation and empirical evidence

When implementing new information systems, organizations often face resistance behavior from employees who avoid or underutilize the system. We analyze the extent to which such user resistance behavior is explained by users’ perceptions of the technology compared with their perceptions of work routines. We developed a research model based on work system theory and evaluated it using a study (N=106) of a human resources information system implementation in one organization. The results show that work routines are an object of resistance during IS implementations. We identify perceived usefulness and perceived ease of executing work routines as perceptions of work routines during an IS implementation that have a strong influence on user resistance behavior. In addition, our results show that the perceived ease of executing the work routines mediates the impact of perceived ease of use on user resistance behavior. In practice, our findings imply that interventions during IT implementations should focus on both the new technology and changing work routines.     

Improving shift workers' health and tolerance to shiftwork: recent advances

Recent developments in research in relation to health and tolerance to shiftwork offer useful guidance for improving conditions of shiftwork. These developments were discussed by the papers of this special issue, presented at the Mini-symposium on improving shift workers' health and tolerance to shiftwork in the 24th International Congress on Occupational Health in Nice, France, in 1993. While there is evidence that shiftwork is regarded as a risk factor with respect to the health of shift workers, many shift workers are engaged in shift systems for years while coping with associated burdens in their working life. In order to improve shift workers' health and tolerance, recent research points to the importance of multifaceted measures addressing both the effects of disruptions in circadian rhythms, and the actual interferences with daily routines at work and in family and social life. Increasing attention is paid to changed working hours and shift systems, including more flexible shiftwork systems, as well as to supporting effective coping activities and occupational health services. As shown by the new ILO Convention on night work, a consensus is being built internationally that multifaceted actions are necessary for improving shiftworking conditions and that such actions should be based on participatory planning and implementation.     

Investigating risk factors for slips, trips and falls in New Zealand residential construction using incident-centred and incident-independent methods

Slip, trip and fall (STF) incidents, particularly falls from a height, are a leading cause of injury in the New Zealand residential construction industry. The most common origins of falls from a height in this sector are ladders, scaffolding and roofs, while slipping is the most frequent fall initiating event category. The study aimed to provide detailed information on construction industry STF risk factors for high-risk tasks, work equipment and environments, as identified from an earlier analysis of STF claims data, together with information to be used in the development of interventions to reduce STF risk in New Zealand residential construction. The study involved the use of both incident-centred and incident-independent methods of investigation, including detailed follow-up investigations of incidents and observations and interviews with workers on construction sites, to provide data on a wide range of risk factors. A large number of risk factors for residential construction STFs were identified, including factors related to the work environment, tasks and the use and availability of appropriate height work equipment. The different methods of investigation produced complementary information on factors related to equipment design and work organization, which underlie some of the site conditions and work practices identified as key risk factors for residential construction STFs. A conceptual systems model of residential construction STF risk is presented.     

Working conditions of Iranian hand-sewn shoe workers and associations with musculoskeletal symptoms

The working conditions and the prevalence of self-reported musculoskeletal symptoms among 180 Iranian hand-sewn shoe workers were evaluated in this cross-sectional study. Data were collected using both questionnaire (for assessing musculoskeletal symptoms and associated risk factors) and direct observations of posture (by the Rapid Upper Limb Assessment [RULA] method). The prevalence and severity of symptoms was very high among the study population. The mean RULA grand score of 6.2 indicates that in most cases the workers' postures at their workstations need to be investigated and some changes are required immediately. Multiple logistic regression models indicated that the job experience, daily working hours, duration of continuous work without breaks, feeling pressure due to work and working postures were significantly associated with musculoskeletal symptoms of different body regions. The results are discussed in terms of their implications for hand-sewing tasks. These findings can help to better understand the working conditions of those jobs involving hand-sewing operation and highlight the potential for ergonomic interventions to reduce musculoskeletal symptoms among these working groups.

Practitioner Summary: Working conditions of hand-sewn shoe workers and their musculoskeletal symptoms were investigated. The prevalence and severity of musculoskeletal symptoms was very high among the study population. Poor working postures, feeling pressure due to work, long duration of work without breaks and prolonged daily working hours were positively associated with musculoskeletal symptoms.     

Investigating risk factors for slips,trips and falls in New Zealand residential construction using incident-centred and incident-independent methods

Slip, trip and fall (STF) incidents, particularly falls from a height, are a leading cause of injury in the New Zealand residential construction industry. The most common origins of falls from a height in this sector are ladders, scaffolding and roofs, while slipping is the most frequent fall initiating event category. The study aimed to provide detailed information on construction industry STF risk factors for high-risk tasks, work equipment and environments, as identified from an earlier analysis of STF claims data, together with information to be used in the development of interventions to reduce STF risk in New Zealand residential construction. The study involved the use of both incident-centred and incident-independent methods of investigation, including detailed follow-up investigations of incidents and observations and interviews with workers on construction sites, to provide data on a wide range of risk factors. A large number of risk factors for residential construction STFs were identified, including factors related to the work environment, tasks and the use and availability of appropriate height work equipment. The different methods of investigation produced complementary information on factors related to equipment design and work organization, which underlie some of the site conditions and work practices identified as key risk factors for residential construction STFs. A conceptual systems model of residential construction STF risk is presented.     

The work load of warehouse workers in three different working systems

An investigation was conducted in five companies in the distribution branch. These companies were divided into three different working systems, i.e., highly mechanized (HM), moderately mechanized (MM), and slightly mechanized (SM). The three systems differed in logistics and kind of appliances used. The purpose of this study was to compare the three working systems with different degrees of mechanization concerning the time spent on tasks, activities during the working day, postures that occurred, physiological work load, perceived exertion and recovery from work. To investigate the different tasks, activities and working postures, 50 warehouse workers, originating from the three working systems, were observed by means of a direct observation method, called: ‘TRAC’. To investigate the physiological work load the heart rate was recorded continuously during the working day and related to the individually determined relation between heart rate and oxygen uptake. This relation was constructed with the results of a cycle ergometer test done in the laboratory. During lunch and at the end of the working day the warehouse workers filled in a questionnaire concerning their perceived exertion and recovery from work.

In the slightly mechanized system more time was spent with the trunk flexed more than 75° as compared with the other two systems. This posture was very common during lifting of objects, and lifting was done more often in this system than in the other systems. In the MM system the warehouse workers had the highest estimated oxygen uptake and reported the highest perceived exertion at the end of the working day. The workers in the HM system had a shorter working day and had less problems with recovery from work than the workers of the other two systems. Poor working postures like rotation and lateroflexion were commonly found in the HM working system. An important explanation was the difference in time spent driving an electric car. This activity was done mostly in the HM system. In conclusion, the HM system was considered most favourable when it concerned work load and recovery from work. The appliances used in the HM system, and especially the electric car, need to be designed according to ergonomic guidelines to avoid poor working postures.