CONTENTS:

Articles:

PROTECTION OF HUMAN IN THE WORKING ENVIRONMENT

Exposure of Workers to Electromagnetic Fields. A Review of Open Questions on Exposure Assessment Techniques Kjell Hansson Mild, Tommi Alanko, Gilbert Decat, Rosaria Falsaperla, Krzysztof Gryz, Maila Hietanen, Jolanta Karpowicz, Paolo Rossi, Monica Sandström 3-33 Coronary Heart Disease Risk Factors and Cardiovascular Risk in Physical Workers and Managers Joanna Bugajska, Janina Małgorzata Michalak, Anna Jędryka-Góral, Adam Sagan, Maria Konarska 35-43 A Parallel Graded-Mesh FDTD Algorithm for Human–Antenna Interaction Problems Luca Catarinucci, Luciano Tarricone 45-52 A Study on the Effect of Human Laterality, Type of Computer and Noise on Operators’ Performance of a Data Entry Task Zahid A. Khan, Sayed Aliul H. Rizvi 53-60

PROTECTION OF HUMAN AT THE WORKSTATION

Physiological Effects of a Modification of the Construction of Impermeable Protective Clothing Anna Marszałek, Grażyna Bartkowiak, Krzysztof Łężak 61-73 A Video-Based Observation Method to Assess Musculoskeletal Load in Kitchen Work Irmeli Pehkonen, Ritva Ketola, Riikka Ranta, Esa-Pekka Takala 75-88 Optical Properties of Plane and Convex Mirrors: Investigation of Mirror Use to Enhance Construction Flagger Safety Edward Stevens Jr, Martin Cohen, Peregrin Spielholz 89-100 Risk Observatory—A Tool for Improving Safety and Health at the Workplace Karin Reinhold, Marina Järvis, Piia Tint 101-112

NOTES

An Ergonomics Approach Model to Prevention of Occupational Musculoskeletal Injuries Altan Koltan 113-124 Investigation of Dust Levels in Different Areas of Underground Coal Mines Mustafa Önder, Seyhan Önder, Tuncay Akdag, Firat Ozgun 125-130

Exposure of Workers to Electromagnetic Fields. A Review of Open Questions on Exposure Assessment Techniques
Kjell Hansson Mild, Tommi Alanko, Gilbert Decat, Rosaria Falsaperla, Krzysztof Gryz, Maila Hietanen, Jolanta Karpowicz, Paolo Rossi, Monica Sandström


European Directive 2004/40/EC on occupational exposure to electromagnetic fields (EMF), based on the guidelines of the International Commission on Non-Ionizing Radiation Protection, was to be implemented in the Member States of the European Union by 2008. Because of some unexpected problems the deadline was postponed until 2012. This paper reviews some of the problems identified and presents some suggestions for possible solutions based on the authors’ experience in assessing occupational exposure to EMF. Among the topics discussed are movement in static magnetic fields, ways to time average extreme low frequency signals, the difference between emission and exposure standards, and ways of dealing with those issues.

Coronary Heart Disease Risk Factors and Cardiovascular Risk in Physical Workers and Managers
Joanna Bugajska, Janina Małgorzata Michalak, Anna Jędryka-Góral, Adam Sagan, Maria Konarska


This study aimed to assess the incidence of coronary heart disease (CHD) risk factors and cardiovascular risk in physical workers and managers in Poland. There were 232 male subjects: 123 managers (48.9 ± 11.2 years old) and 109 physical workers (37.5 ± 11.1 years old). The family history of CHD was recorded and anthropometric and biochemical indices, i.e., body mass index, visceral obesity index, blood pressure, glucose, total cholesterol, fibrinogen, HDL (high density lipoprotein), LDL (low density lipoprotein) and triglycerides were measured. Cardiovascular risk was assessed with the Systematic Coronary Risk Evaluation (SCORE) table system. The factors that turned out to be the most common in the managers were obesity, hypertension, and elevated levels of blood glucose and LDL, whereas cigarette smoking, premature CHD in the family and a high level of fibrinogen were more common in physical workers. Very high cardiovascular risk was found in 35% of managers and in 16% of physical workers.

A Parallel Graded-Mesh FDTD Algorithm for Human–Antenna Interaction Problems
Luca Catarinucci, Luciano Tarricone


The finite difference time domain method (FDTD) is frequently used for the numerical solution of a wide variety of electromagnetic (EM) problems and, among them, those concerning human exposure to EM fields. In many practical cases related to the assessment of occupational EM exposure, large simulation domains are modeled and high space resolution adopted, so that strong memory and central processing unit power requirements have to be satisfied. To better afford the computational effort, the use of parallel computing is a winning approach; alternatively, subgridding techniques are often implemented. However, the simultaneous use of subgridding schemes and parallel algorithms is very new. In this paper, an easy-to-implement and highly-efficient parallel graded-mesh (GM) FDTD scheme is proposed and applied to human–antenna interaction problems, demonstrating its appropriateness in dealing with complex occupational tasks and showing its capability to guarantee the advantages of a traditional subgridding technique without affecting the parallel FDTD performance.

A Study on the Effect of Human Laterality, Type of Computer and Noise on Operators’ Performance of a Data Entry Task
Zahid A. Khan, Sayed Aliul H. Rizvi


Effects of human laterality, type of computer and noise on computer operators’ performance of a data entry task were investigated. Seven right- and 7 left-motorsided male subjects performed the task on desktop and laptop computers in a sitting posture under varying noise levels. The mean number of characters entered per minute was statistically analysed. The right-motorsided operators entered more data than left-motorsided ones at each noise level. Operators performed better on desktop computers. Operators’ performance decreased when noise level increased from 82 to 92 dB(A) but it improved at 102 dB(A). Effects of laterality, type of computer and noise, and the interaction between laterality and noise were statistically significant. The interactions between laterality and type of computer, and type of computer and noise were statistically insignificant. Laterality was statistically significant at all noise levels and noise was statistically significant for right motor-sided operators only.

Physiological Effects of a Modification of the Construction of Impermeable Protective Clothing
Anna Marszałek, Grażyna Bartkowiak, Krzysztof Łężak


This study was conducted to improve the construction of impermeable clothing protecting against liquid chemical agents in order to lower the thermal strain caused by the clothing during work. Previous studies indicated that light work in a hot environment in this kind of clothing could last 30 min only. We propose a modification of the construction; new models of protective clothing were tested in wear trials. Then the results were compared with a basic model of impermeable protective clothing. Results indicated that all new models of protective clothing allowed workers to work 39–64% longer than in a basic model of protective clothing. Thus new clothing significantly improved comfort of work in impermeable protective clothing because of the lower thermal strain that it imposed on the user.

A Video-Based Observation Method to Assess Musculoskeletal Load in Kitchen Work
Irmeli Pehkonen, Ritva Ketola, Riikka Ranta, Esa-Pekka Takala


This paper describes a new video-based observation method aimed to assess musculoskeletal load in kitchen work, aspects of its repeatability and validity, and problems confronted by the observers. Two pairs of researchers observed individually 117 video clips recorded in kitchens. Interobserver repeatability was assessed by computing the proportion of agreement and weighted kappa values (κw). Validity was analyzed by studying the distribution of the assessments over the rating scales and the ratings before and after the interventions, which were compared with expert assessments made from the same intervention targets. The proportion of agreement ranged from 57 to 88%. Interobserver repeatability based on weighted kappa values was mainly good to moderate. The method detected the changes in physical load due to the interventions. Direction of the changes corresponded with the expert assessments. Further development of the method is needed to assess the load on the hands and wrists.

Optical Properties of Plane and Convex Mirrors: Investigation of Mirror Use to Enhance Construction Flagger Safety
Edward Stevens Jr, Martin Cohen, Peregrin Spielholz


Legislation and product development in the USA has prompted an interest in mirror-use by traffic flaggers to improve awareness of vehicles approaching from behind. Helmet- and flagpole-mounted configurations were studied using a graphical approach with field verification studies by comparing fields of view, object magnifications, and human factors considerations. Plane and convex mirrors with different radii of curvature were investigated. Results found image formation on helmet-mounted convex mirrors occurs too close to the mirror. A 0.038 m helmet-mounted plane mirror performed similarly to a 0.076 m diameter, 0.508 m radius of curvature convex mirror. Fields of view and image information between helmet-mounted plane mirrors and flagpole-mounted convex mirrors were compared. Issues of image perception, practical use, and attention were identified; they pose serious issues for use as a primary safety device. Additional investigation is needed to determine the requirements and applicability of mirror-use for flagging in work zones.

Risk Observatory—A Tool for Improving Safety and Health at the Workplace
Karin Reinhold, Marina Järvis, Piia Tint


The main problems in occupational health and safety (OHS) system in Estonia (a postcommunist new European Union Member State) are analyzed and the implementation of a simple, flexible risk assessment method is presented. The study aimed to assess the working environment, the employers’ possibilities and willingness to carry out risk assessment, ways to manage risks and the steps being taken towards progressive improvement in OHS. The role of the Estonian Labour Inspectorate in the risk observatory is that of the main key authority in data collection and information dissemination in OHS.

An Ergonomics Approach Model to Prevention of Occupational Musculoskeletal Injuries
Altan Koltan


The objective of this study was to prevent occupational musculoskeletal injuries. Our workers stacked boxes of ceramics weighing 10–27 kg, making low back pain common in our enterprise. In all the stacking stations, recommended weight limits (RWL) were separately calculated using the revised National Institute for Occupational Health lifting equation. Since the boxes weighed significantly more than the RWL, we developed a new ergonomic design that completely changed the stacking process. The load put on the workers’ waist vertebrae in the new and the old stacking methods was compared to evaluate the success of the new ergonomic design, using Newton’s third law of motion. Thanks to the new ergonomic design, the load on the workers’ vertebrae decreased by 80%. Due to its simple technology and its very low cost compared to robots, the new ergonomic design can be commonly used in enterprises with repeated and constraining stacking.

Investigation of Dust Levels in Different Areas of Underground Coal Mines
Mustafa Önder, Seyhan Önder, Tuncay Akdag, Firat Ozgun


Dust concentration levels in underground coal mines are of primary importance and have to be controlled to prevent pulmonary disease in miners. Different mining areas are exposed to different dust levels and to minimize the probability of occupational respiratory disease of coal miners, it is necessary to evaluate dust concentration in the different working areas. This study aimed to evaluate dust concentration levels in different areas of underground coal mines. Data obtained from the measurements in 1978–2006 were evaluated with the analysis of variance (ANOVA) and the Tukey-Kramer procedure. It was concluded that production areas had higher dust concentration levels; thus, production workers may have respiratory disorders related to exposure to coal dust in their work environment.