CONTENTS:

Articles:

PROTECTION OF HUMAN IN THE WORKING ENVIRONMENT

Cooling Suits, Physiological Response, and Task Performance in Hot Environments for the Power Industry Alwyn L. Furtado, Brian N. Craig, Joshua T. Chard, Victor A. Zaloom & Hsing-Wei Chu, 227-239     A Study of the Influence of Muscle Type and Muscle Force Level on Individual Frequency Bands of the EMG Power Spectrum Paweł Bartuzi, Danuta Roman-Liu & Tomasz Tokarski, 241-254       An Empirical Investigation of the Influence of Safety Climate on Organizational Citizenship Behavior in Taiwan’s Facilities Tzai-Zang Lee, Chien-Hsing Wu & Chih-Wei Hong, 255-269       A Comparative Assessment of the Impact of Different Occupations on Workers’ Static Musculoskeletal Fitness Ananga M. Chandra, Suhana Ghosh, Rauf Iqbal & Nachiketa Sadhu, 271-278

PROTECTION OF HUMAN AT THE WORKSTATION

Biomechanical Assessment of Three Rebar Tying Techniques James T. Albers & Stephen D. Hudock, 279-289     Investigating Data Entry Task Performance on a Laptop Under the Impact of Vibration: The Effect of Color Zulquernain Mallick, 291-303       Low Back Pain Among Residential Carpenters: Ergonomic Evaluation Using OWAS and 2D Compression Estimation David P. Gilkey, Thomas J. Keefe, Philip L. Bigelow, Robin E. Herron, Kirby Duvall, Jacob E. Hautaluoma, John S. Rosecrance & Richard Sesek, 305-321     Cardiovascular Stress, Energy Expenditure and Subjective Perceived Ratings of Fire Fighters During Typical Fire Suppression and Rescue Tasks Joanna Bugajska, Krystyna Zużewicz, Magdalena Szmauz-Dybko & Maria Konarska, 323-331

NOTES

A Discussion of Occupational Health and Safety Management for the Catering Industry in China Chen Qiang & Wan Ki Chow, 333-339     Occupational Exposure to Asbestos During Renovation of Oil-Shale Fuelled Power Plants in Estonia Maie Kangur, 341-346

Cooling Suits, Physiological Response, and Task Performance in Hot Environments for the Power Industry
Alwyn L. Furtado, Brian N. Craig, Joshua T. Chard, Victor A. Zaloom & Hsing-Wei Chu


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.

A Study of the Influence of Muscle Type and Muscle Force Level on Individual Frequency Bands of the EMG Power Spectrum
Paweł Bartuzi, Danuta Roman-Liu & Tomasz Tokarski


The aim of this study was to analyse the electromyographic (EMG) power spectrum indicating differences in the frequency bands of the spectrum resulting from differences in muscle type and force level for the extensor digitorum (ED), palmaris longus (PL) and biceps brachii (BB) muscles. The study was performed on 12 young men as 2 tests different in terms of the type of exerted force (30, 15 and 5% MVC, maximum voluntary contraction). The parameters of the EMG power spectrum were obtained as a result of a division of the EMG power spectrum into ranges determined by border frequencies. The results suggest that (a) frequency bands contained in the 30–80 Hz range and over the frequency of 300 Hz depend on muscle force, and (b) the power spectrum in the frequency range of up to 40 Hz and 60–300 Hz indicates muscle type.

An Empirical Investigation of the Influence of Safety Climate on Organizational Citizenship Behavior in Taiwan’s Facilities
Tzai-Zang Lee, Chien-Hsing Wu & Chih-Wei Hong


Although the social exchange relationships between employers and employees are increasingly important to the performance of safety management systems, the psychological effects of work attitudes on this relationship have been less studied. Using a sample of first-line operators and their supervisors from 188 facilities in Taiwan which had Occupational Health and Safety Assessment Series 18000 (OHSAS 18000) certification, the current research conducted an empirical investigation of the influence of safety climate on organizational citizenship behavior (OCB). Work attitude was used to disclose the psychological effect. Research results indicated that (a) safety climate was a significant predicator of OCB, (b) the psychological effect significantly influenced social exchange relationships, and (c) job satisfaction showed a stronger mediating influence than organizational commitment due to the frequent top management turnover. Discussions and implications are also addressed.

A Comparative Assessment of the Impact of Different Occupations on Workers’ Static Musculoskeletal Fitness
Ananga M. Chandra, Suhana Ghosh, Rauf Iqbal & Nachiketa Sadhu


An ergonomic assessment of the involvement of static muscular forces like back strength, grip strength and pinch strength in different occupations was made. A study was conducted on 45 normal adult males (15 subjects per group) which included video display terminal (VDT) operators, industrial workers and safety inspectors. Their maximum back strength, handgrip strength and pinch strength were measured with dynamometers. The observed values of back strength were significantly lower in VDT operators while significantly higher in safety inspectors and moderate in industrial workers. The values of grip strength and pinch strength of all sample groups were more or less similar. The findings clearly indicate that static muscular strength varies significantly in different occupations. Heavy static muscular load might lead to an accumulation of metabolic waste and toxins on the back resulting in lower back strength in VDT operators and industrial workers.

Biomechanical Assessment of Three Rebar Tying Techniques
James T. Albers & Stephen D. Hudock


The National Institute for Occupational Safety and Health (NIOSH) conducted a study of ironworkers to evaluate their risk for developing back and hand injuries from hand-tying reinforcing steel bar and to investigate whether power tying tools can be an effective intervention for the prevention of work-related musculoskeletal disorders. A field investigation of biomechanical loading when using 3 techniques to tie together rebar was conducted. Researchers measured employees’ wrist and forearm movement with goniometers and videotaped and analyzed trunk postures. Manually tying rebar at ground level involved sustained deep trunk bending and rapid, repetitive, and forceful hand–wrist and forearm movements. Using a power tier significantly reduced the hand–wrist and forearm movements and allowed the ironworkers to use one free hand to support their trunk posture while tying. Adding an extension handle to the power tier allowed the ironworkers to tie rebar while standing erect, minimizing sustained trunk flexion.

Investigating Data Entry Task Performance on a Laptop Under the Impact of Vibration: The Effect of Color
Zulquernain Mallick


The last 20 years have seen a tremendous growth in mobile computing and wireless communications and services. An experimental study was conducted to explore the effect of text/background color on a laptop computing system along with variable environmental vibration on operators’ data entry task performance in moving automobiles. The operators’ performance was measured in terms of the number of characters entered per minute without spaces (NCEPMWS) on a laptop computing system. The subjects were divided into 3 categories, namely, Novices, Intermediates and Experts. Findings suggest a re-evaluation of existing laptop designs taking ergonomics into consideration. It appears that proper selection of text/background color on the laptop coupled with controlled vehicular speed could result in a better quality of interaction between human and laptops and it could also resolve the problem of poor data entry task performance.

Low Back Pain Among Residential Carpenters: Ergonomic Evaluation Using OWAS and 2D Compression Estimation
David P. Gilkey, Thomas J. Keefe, Philip L. Bigelow, Robin E. Herron, Kirby Duvall, Jacob E. Hautaluoma, John S. Rosecrance & Richard Sesek


Occupational low back pain (LBP) remains a leading safety and health challenge. This cross-sectional investigation measured the prevalence of LBP in residential carpenters and investigated ergonomic risk factors. Ninety-four carpenters were investigated for LBP presence and associated risk factors. Ten representative job-tasks were evaluated using the Ovako Working Posture Analysis System (OWAS) and ErgoMaster™ 2D software to measure elements of posture, stress, and risk. Job-tasks were found to differ significantly for total lumbar compression and shear at peak loading (p < .001), ranging from 2 956 to 8 606 N and 802 to 1 974 N respectively. OWAS indicated that slight risk for injury was found in 10 job-tasks while distinct risk was found in 7 of the 10 job-tasks. Seven of the 10 job-tasks exceeded the National Institute for Occupational Safety and Health (NIOSH) action limit of 3 400 N for low back loading. The point prevalence for LBP was 14% while the annual prevalence was 38%.

Cardiovascular Stress, Energy Expenditure and Subjective Perceived Ratings of Fire Fighters During Typical Fire Suppression and Rescue Tasks
Joanna Bugajska, Krystyna Zużewicz, Magdalena Szmauz-Dybko & Maria Konarska


The study determined physiological and psychophysical responses to fire fighters’ typical activities. Selfreported assessment of the most demanding fire fighting/rescue tasks were collected with a questionnaire. Then 19 voluntary fire fighters performed 3 simulated fire fighting/rescue tasks in protective clothing. Heart rate (HR), blood pressure and energy expenditure were measured; the rating of perceived exertion (RPE) was assessed with the Borg scale. The questionnaires showed that carrying out victims, fire suppression and resuscitation were classified as heavy load; climbing stairs with a hose as moderate load. According to RPE the subjects considered their effort during ladder climbing fairly light and only somewhat harder during stair climbing and carrying out injured people. The study demonstrated that typical fire fighting/rescue tasks were associated with high energy expenditure and imposed considerable cardiovascular stress. The Borg scale appeared not suitable for assessing perceived exertion in fire fighters during simulated tasks.

A Discussion of Occupational Health and Safety Management for the Catering Industry in China
Chen Qiang & Wan Ki Chow


The catering industry is developing rapidly in China. Statistics in 2002 indicated that there were over 3.5 million dining places in China, hiring over 18 million people. However, the accident rate was high. Occupational health and safety (OHS) has to be watched more carefully. It is proposed to develop an OHS management system for the catering industry and to integrate it with an ongoing management system by referring to OHSAS 18001:1999. The first step is risk identification and evaluating the major factors concerned by referring to the codes in China, the list of occupational diseases, operation rules, requirements of the law, and records of past incidents. The technological aspect has to be considered in working out the safety strategies. This includes technical measures in accident prevention at the workplace. The kitchen is the main area to be focused on. Methods for hazard identification and risk assessment of dangerous factors in kitchens are proposed in this paper.

Occupational Exposure to Asbestos During Renovation of Oil-Shale Fuelled Power Plants in Estonia
Maie Kangur


Many thousands of tonnes of asbestos were used in buildings in the past, especially for thermal insulation of pipes and boilers in power plants. Occupational exposure to asbestos dust now mainly occurs during demolition, renovation and routine maintenance activities. The objective of this study was to evaluate occupational exposure to airborne asbestos during renovation of solid oil-shale fuelled power plants carried out in 2001–2003. Air monitoring inside and outside of the renovation area was performed. The concentration of airborne fibres in the working environment increased during renovation but the valid limit value (0.1 fibres/cm3) was not exceeded.