CONTENTS:

Articles:

PROTECTION OF HUMAN IN THE WORKING ENVIRONMENT

Will Musculoskeletal, Visual and Psychosocial Stress Change for Visual Display Unit (VDU) Operators When Moving From a Single-Occupancy Office to an Office Landscape? Magne Helland, Gunnar Horgen, Tor Martin Kvikstad, Tore Garthus, Arne Aarås 259-274 Perceived Mental Stress and Reactions In Heart Rate Variability—A Pilot Study Among Employees of an Electronics Company Reetta Orsila, Matti Virtanen, Tiina Luukkaala, Mika Tarvainen, Pasi Karjalainen, Jari Viik, Minna Savinainen, Clas-Hakån Nygård 275-283 Factors Attributed to Fatal Occupational Accidents in a Period of 5 Years Preceding the Athens 2004 Olympic Games Panagiota Katsakiori, Emmanuel Manatakis, Stavros Goutsos, George Athanassiou 285-292 Readability of Characters on Mobile Phone Liquid Crystal Displays Satoshi Hasegawa, Kazuhiro Fujikake, Masako Omori, Masaru Miyao, 293-304 A Comparison of Muscular Activity Involved in the Use of Two Different Types of Computer Mouse Rupesh Kumar, Shrawan Kumar, 305-311

PROTECTION OF HUMAN AT THE WORKSTATION

Sustained Operations in Confined-Space Military Vehicles Nico J. Delleman, Véronique Colaciuri, Emeric Wiederkehr, Pierre J.L. Valk 313-325 Safety Performance Factor Naray Venkataraman 327-331 Occupational Hazards and Illnesses of Filipino Women Workers in Export Processing Zones Jinky Leilanie Lu 333-342 Evaluation and Optimization of Handle Design Parameters of a Grass Trimming Machine Zulquernain Mallick 343-349

NOTES

Ergonomics Interventions at Badger Mining Corporation Janet Torma-Krajewski, Martin Lehman, 351-359

Will Musculoskeletal, Visual and Psychosocial Stress Change for Visual Display Unit (VDU) Operators When Moving From a Single-Occupancy Office to an Office Landscape?
Magne Helland, Gunnar Horgen, Tor Martin Kvikstad, Tore Garthus, Arne Aarås


This study investigated the effect of moving from single-occupancy offices to a landscape environment. Thirty-two visual display unit (VDU) operators reported no significant change in visual discomfort. Lighting conditions and glare reported subjectively showed no significant correlation with visual discomfort. Experience of pain was found to reduce subjectively rated work capacity during VDU tasks. The correlation between visual discomfort and reduced work capacity for single-occupancy offices was rs = .88 (p = .000) and for office landscape rs = .82 (p = .000). Eye blink rate during habitual VDU work was recorded for 12 operators randomly selected from the 32 participants in the office landscape. A marked drop in eye blink rate during VDU work was found compared to eye blink rate during easy conversation. There were no significant changes in pain intensity in the neck, shoulder, forearm, wrist/hand, back or headache...

Perceived Mental Stress and Reactions In Heart Rate Variability—A Pilot Study Among Employees of an Electronics Company
Reetta Orsila, Matti Virtanen, Tiina Luukkaala, Mika Tarvainen, Pasi Karjalainen, Jari Viik, Minna Savinainen, Clas-Hakån Nygård


In this study perceived mental stress during occupational work was compared to heart rate variability (HRV) using a traditional questionnaire and a novel wristop heart rate monitor with related software. The aim was to find HRV parameters useful for mental stress detection. We found the highest correlation between perceived mental stress with the differences between the values of triangular interpolation of rythm-to-rythm (RR) interval histogram (TINN) and the root mean square of differences of successive RR intervals (RMSSD) obtained in the morning and during the workday (r = –.73 and r = –.60, respectively). The analysis shows that as the RMSSD and TINN value differences increase from night to morning, the stress decreases.

Factors Attributed to Fatal Occupational Accidents in a Period of 5 Years Preceding the Athens 2004 Olympic Games
Panagiota Katsakiori, Emmanuel Manatakis, Stavros Goutsos, George Athanassiou


This study aimed to determine the factors attributed to occupational fatalities occurring in the region of East Attica, Greece, in all industry types over a 5-year period preceding the 2004 Olympic Games. Questionnaires, based on the attribution theory, were completed by labor inspectors and were analyzed with principal component analysis. The results showed that most accidents occurred in the construction industry due to large-scale civil works, which took place in East Attica prior to the 2004 Olympic Games. Poor work practices arising from lack of orientation and job training, performance pressure and workers’ inexperience associated with knowledge- and skill-based errors were revealed by the questionnaire as the most common factors attributed to occupational fatalities. Our findings help to identify areas where prevention efforts should be directed to effectively manage safety in Greece.

Readability of Characters on Mobile Phone Liquid Crystal Displays
Satoshi Hasegawa, Kazuhiro Fujikake, Masako Omori, Masaru Miyao


Subject performance in reading characters on mobile phone liquid crystal displays was researched by using (a) English sentences with 3 or 4 different sizes of characters on 2 types of displays with different resolutions (n = 23; age = 31.0 ± 6.0 years), (b) Japanese characters in 3 different sizes and 2 types of font (n = 98; age = 44.5 ± 18.5 years), and (c) Japanese characters vertically enlarged 1–4 times (n = 120; age = 46.9 ± 18.6 years). Subjective evaluation, reading speed, number of reading errors, and viewing distance were recorded. Readability was higher with higher resolution displays, and with Gothic than with Mincho font in Japanese. Young subjects shortened the viewing distance as characters became smaller, whereas elderly subjects increased the viewing distance irrespective of the size of characters. Characters of 3–5 mm are appropriate for the young but inadequate for the elderly. Readability of Japanese characters improved when they were vertically enlarged to approximately twice the width.

A Comparison of Muscular Activity Involved in the Use of Two Different Types of Computer Mouse
Rupesh Kumar, Shrawan Kumar


Two types of computer input devices, a conventional mouse and a roller bar one, were studied in terms of muscular activitiy in m. trapezius dexter, m. deltoideus anterior dexter and m. extensor digitorum dexter, and comfort rating. Fifteen university students and employees participated in this study. The order of the devices was random. While a task was performed, electromyography (EMG) data were recorded for each test. Muscular activity was found to be significantly lower for the roller bar mouse than for the conventional one. Comfort rating indicated there was a significant difference in moving a cursor with the conventional mouse compared to the roller bar one. It is concluded that a roller bar mouse allowed the subjects to work closer to the body compared to the conventional one, thus the former can be recommended as a general means of reducing upper extremity musculoskeletal disorders.

Sustained Operations in Confined-Space Military Vehicles
Nico J. Delleman, Véronique Colaciuri, Emeric Wiederkehr, Pierre J.L. Valk


This paper reports 2 baseline studies and 1 experiment performed in a confined-space military vehicle concerning the effects on fitness and performance of time in a sitting posture and workstation characteristics. On average physical fitness decreased by slightly more than 10% per hour, the observation performance decreased by ~30% per hour, and the technical performance (of gunners) showed a relatively small decrease, i.e., less than 5% per hour. So-called active breaks (changing sitting into standing and walking) led to a significant reduction in the decrease of physical fitness, almost reducing it to zero. Furthermore, the level of confinement was shown to affect physical fitness.

Safety Performance Factor
Naray Venkataraman


Workplace safety performance is computed using frequency rate (FR) and severity rate (SR). Only work time lost due to occupational incidents that need to be reported is counted. FR and SR are the 2 most important safety performance indicators that are applied universally; however, calculations differ from country to country. All injuries and time lost should be considered while calculating safety performance. The extent of severity does not matter as every incident is counted. So, a new factor has to be defined; it should be based on the hours or days lost due to each occupational incident, irrespective of its severity. The new safety performance factor is defined as the average human-hour unit lost due to occupational accidents/incidents, including fatalities, first-aid incidents, bruises and cuts. The formula is simple and easy to apply.

Occupational Hazards and Illnesses of Filipino Women Workers in Export Processing Zones
Jinky Leilanie Lu


This was a baseline study on occupational exposure and health problems among women workers in export processing zones. Physical, chemical, and ergonomic hazards were evaluated and measured through workplace ambient monitoring, survey questionnaires, and interviews with 500 respondents in 24 companies (most were female at 88.8%). The top 5 hazards were ergonomic hazards (72.2%), heat (66.6%), overwork (66.6%), poor ventilation (54.8%), and chemical exposure (50.8%). The most common illnesses were gastrointestinal problems (57.4%), backache (56%), headache (53.2%), and fatigue/weakness (53.2%). Logistic regression showed an association between certain work-related factors and occupational illnesses, and psychosocial problems. Highly significant associations were hearing loss with years spent in the company (p = .005) and gender (p = .006), headache and dizziness with poor ventilation (p = .000), backache with prolonged work (p = .003). These results will have implications for policy and program formulation for women workers’ concerns and issues in export zones.

Evaluation and Optimization of Handle Design Parameters of a Grass Trimming Machine
Zulquernain Mallick


The grass trimming machine is a widely used agricultural machine for cutting grass by the roadside and in other areas in Malaysia. Hand–arm vibration (HAV) syndrome is very common among workers operating power tools and performing similar work for extended periods. Grass trimming involves the use of a motorized cutter spinning at high speed, resulting in high levels of HAV among its operators. The existing D-shape handle causes HAV-related stress and operational load in operators. This research proposes a new design of a handle of the grass trimming machine. When this new design was compared with the old one, it was found that the new handle resulted in 18% lower HAV. To find the lowest HAV, 3 critical parameters of the new handle (length, angle and material of the cap of the handle) were optimized using the Taguchi quality tool. Appropriately selected parameters of the new handle significantly reduced the occurrence of HAV among grass trimmers.

Ergonomics Interventions at Badger Mining Corporation
Janet Torma-Krajewski, Martin Lehman


In 2005, the National Institute for Occupational Safety and Health (NIOSH) and Badger Mining Corporation entered a partnership to implement ergonomics interventions, including a systematic process, to address exposure to risk factors that may result in musculoskeletal disorders or other types of injuries/illnesses. As a result of this partnership, an ergonomics process was integrated with the existing safety and health programme to promote an on-going application of ergonomics principles, and over 40 task-specific interventions were implemented during the first year of the process. This paper presents details of the process integration, and several examples of task-specific interventions that reduced exposure to risk factors.