Determination of Heat Loss from the Feet and Insulation of the Footwear Kalev Kuklane, Rallema Afanasieva, Olga Burmistrova, Nina Bessonova, Ingvar Holmér, 465-476 A Comparison of Two Methods of Determining Thermal Properties of Footwear Kalev Kuklane, Ingvar Holmér, Rallema Afanasieva, 477-484 Job Satisfaction and Importance of Work Aspects Related to Predominant Values and Reactivity Anna M. Zalewska, 485-511 The Relevance of Error Analysis in Graphical Symbols Evaluation Dominic Paul T. Piamonte, 513-528 Determination of Alphacypermethrin in the Air by Capillary Gas Chromatography Krystyna Pomorska, 529-536 Certification of Highly Complex Safety-Related Systems Dietmar Reinert, Michael Schaefer, 537-552 Luminance of the Surround and Visual Fatigue of VDT Operators Agnieszka Wolska, Marcin Śwituła, 553-580

Notes:

Occupational Health Care in Small and Medium-Sized Enterprises Introduction of Services to Craftsmen by Using Their Professional Networks Brigitte Froneberg, Ute Boldt, 581-584 Occupational Health Care in Small and Medium Sized Enterprises How Many Doctors Do We Need and How Do We Ensure Good Care? Brigitte Froneberg, Lutz Wienhold, Detlef Glomm, 585-590 An Analysis of Work Environments and Operations in Hot and Humid Areas Bahador Ghahramani, 591-596

Book review, 597-605
Conference Announcement

Determination of Heat Loss from the Feet and Insulation of the Footwear
Kalev Kuklane, Rallema Afanasieva, Olga Burmistrova, Nina Bessonova, Ingvar Holmér

This study compared the methods of determining the footwear insulation on human participants and the thermal foot model. Another purpose was to find the minimal number of measurement points on the human foot that is needed for insulation calculation. Bare foot was tested at 3 ambient temperatures on 6 participants. Three types of footwear were tested on 2 participants. The mean insulation for a bare foot obtained on the participant and model were similar. The insulation of the warm footwear measured by the 2 methods was also similar. For thin footwear the insulation values from the participants were higher than those from the thermal model. The differences could be related to undefined physiological factors. Two points on foot can be enough to measure the insulation of footwear on human participants
(r = .98). However, due to the big individual differences of humans, and good repeatability and simplicity of the thermal foot method, the latter should be preferred for testing.

A Comparison of Two Methods of Determining Thermal Properties of Footwear
Kalev Kuklane, Ingvar Holmér, Rallema Afanasieva

The present European Standard for footwear testing (Standard No. EN 344:1992; European Committee for Standardization [CEN], 1992) classifies footwear thermally by a temperature drop inside the footwear during 30 min at defined conditions. Today, other methods for footwear thermal testing are also available. The aim of this study was to compare EN 344:1992 with a thermal foot method. Six boots were tested according to both methods. Additional tests with modified standard tests were also carried out. The methods ranked the footwear in a similar way. However, the test according to standard EN 344:1992 is a pass-or-fail test, whereas data that is gained from the thermal foot method gives more information and allows further use in research and product development. A change of the present standard method is suggested.

Job Satisfaction and Importance of Work Aspects Related to Predominant Values and Reactivity
Anna M. Zalewska

The aim of the study is to answer whether 2 predominant values achievement or social relations and reactivity influence (a) the importance of work aspects, (b) satisfaction with them and with overall job satisfaction, (c) connections between overall job satisfaction and satisfaction with work aspects. Bank employees were investigated with the Strelau Temperament Inventory-Revised by Strelau, Angleitner, Bantelman, and Ruch (1990, reactivity), Orientation to Work Values Inventory by Seifert and Bergmann (1983, values), and Work Description Inventory by Neuberger and Allerbeck (1978; importance and satisfaction with work aspects, overall job satisfaction). Predominant values, reactivity, and their interaction influence the importance of work aspects. The values affect overall job satisfaction and satisfaction with Conditions. Reactivity does not affect overall job satisfaction, but it strongly influences the structure of satisfaction with work aspects, and low-reactives compared to high-reactives are more satisfied with 4 out of the 7 considered aspects. Among the high-reactives, connections between overall job satisfaction and satisfaction with work aspects depend on their predominant values. It was concluded that reactivity can modify regulative functions of personal values towards overall job satisfaction: The values have a rather declarative character for low-reactives, but meeting aspirations connected with their values is very important for high-reactives' job satisfaction.

The Relevance of Error Analysis in Graphical Symbols Evaluation
Dominic Paul T. Piamonte

In an increasing number of modern tools and devices, small graphical symbols appear simultaneously in sets as parts of the human-machine interfaces. The presence of each symbolcan influence the other's recognisability and correct association to its intended referents. Thus, aside from correct associations, it is equally important to perform certain error analysis of the wrong answers, misses, confusions, and even lack of answers. This research aimed to show how such error analyses could be valuable in evaluating graphical symbols especially across potentially different user groups. The study tested 3 sets of icons representing 7 videophone functions. The methods involved parameters such as hits, confusions, missing values, and misses. The association tests showed similar hit rates of most symbols across the majority of the participant groups. However, exploring the error patterns helped detect differences in the graphical symbols' performances between participant groups, which otherwise seemed to have similar levels of recognition. These are very valuable not only in determining the symbols to be retained, replaced or re-designed, but also in formulating instructions and other aids in learning to use new products faster and more satisfactorily.

Determination of Alphacypermethrin in the Air by Capillary Gas Chromatography
Krystyna Pomorska

A new method for sampling and chemical analysis of alphacypermethrin in workplace air has been described. Air samples were taken using a glass tube filled with silica gel with chemically bounded octadecyl phase. Chromatographic determinations were conducted using an HP-5 capillary column (10 m x 0.53 mm) and an electron-capture detector. Alphacypermethrin recovery was 100.15%. The calculated detection limit for a 60-L air sample was 0.0001 mg/m³.

Certification of Highly Complex Safety-Related Systems
Dietmar Reinert, Michael Schaefer

 The BIA has now 15 years of experience with the certification of complex electronic systems for safety-related applications in the machinery sector. Using the example of machining centers this presentation will show the systematic procedure for verifying and validating control systems using Application Specific Integrated Circuits (ASICs) and microcomputers for safety functions.
 One section will describe the control structure of machining centers with control systems using"integrated safety." A diverse redundant architecture combined with crossmonitoring and forced dynamisation is explained.
 In the main section the steps of the systematic certification procedure are explained showing some results of the certification of drilling machines. Specification reviews, design reviews with test case specification, statistical analysis, and walk-throughs are the analytical measures in the testing process. Systematic tests based on the test case specification, Electro Magnetic Interference (EMI), and environmental testing, and site acceptance tests on the machines are the testing measures for validation. A complex software driven system is always undergoing modification. Most of the changes are not safety-relevant but this has to be proven. A systematic procedure for certifying software modifications is presented in the last section of the paper.

Luminance of the Surround and Visual Fatigue of VDT Operators
Agnieszka Wolska, Marcin Śwituła

Luminance distribution in the visual field is considered as one of causal factors with a significant influence on visual fatigue, especially for intensive and extended Video Display Terminal (VDT) work. The aim of the study was to define visual fatigue of VDT operators for different values of surrounding luminance. Experiments were carried out in laboratory conditions under 3 lighting conditions. Only 1 lighting parameter the luminance of the wall behind the display (surrounding luminance) changed. Visual fatigue was measured both by a subjective evaluation of different visual complaints (asthenopic symptoms) and by objective measurements of changes in the following visual functions: accommodation, convergence, habitual horizontal phoria, critical fusional frequency (CFF), and visual acuity. The same experiments were done for CRT (Cathode Ray Tube) and LCD TFT (Liquid Crystal Display with Thin Film Transistor) screens. The results of the study have shown that there was no significant influence of the value of surrounding luminance on the asthenopic symptoms for either type of screen. A general tendency towards bigger visual complaints for LCD TFT than for CRT participants was found. An objective evaluation of visual fatigue demonstrated a tendency towards bigger changes in visual functions with an increase of surrounding luminance for both screens. Statistical analysis of the results has shown that surrounding luminance influences significantly the reduction of the accommodation amplitude (significance level < .05).

Notes:

Occupational Health Care in Small and Medium-Sized Enterprises Introduction of Services to Craftsmen by Using Their Professional Networks
Brigitte Froneberg, Ute Boldt

In order to ensure equality of occupational health care among employees of small and medium-sized enterprises (SMEs) and of larger companies amendments in the regulations of the numerous German accident insurance funds had to be made to provide for full availability of services, as requested by German and European law. According to these amendments, sectors formerly exempted due to small size and due to lack of an adequate number of qualified personnel, had to be covered by occupational health care. In order to reach this target group new strategies of care delivery had to be developed, making use of pre-existing infrastructure and networks. In Germany, district trade association (Kreishandwerkerschaften) have proved to be very effective for introducing occupational safety and health care into SMEs by either hiring external multidisciplinary services or by establishing a common service to be used by all associated crafts establishments. In a study conducted by the Federal Office for Health and Safety at Work in 1996 (Boldt, Gille, & Grahl, 1997), 7 district trade association were looked at in detail for their strategies. The results were discussed and supplemented in a 2-day workshop.

Occupational Health Care in Small and Medium Sized Enterprises How Many Doctors Do We Need and How Do We Ensure Good Care?
Brigitte Froneberg, Lutz Wienhold, Detlef Glomm

The translation of the framework directive 89/391/EEC (Council Directive 89/391/EEC) into national law aims at supplying occupational protection and health care to all employees of large, small, and medium-sized enterprises (SMEs) likewise, depending on assessed exposure. Prior incomplete protection of the German workforce with bias against the SMEs requires an assessment of quantitative and qualitative adequacy of present occupational health care practice and also of future needs.
 Therefore, the Federal Institute for Occupational Safety and Health of Germany initiated a study to evaluate the present state of occupational health care in 4 regions with different geographic and economic structure. Based on these data the future demand for adequately trained occupational physicians will be estimated by employing a statistical method that allows for including a large number of modifying variables (economic development, demographic change, etc.).
 Expected result of the applied technique are the estimated minimal and maximal number of occupational physicians that have to be trained to meet future demand. In the same study models of best practice will be identified and evaluated for general application. The project started in October 1997 and will be finished by November 1999

An Analysis of Work Environments and Operations in Hot and Humid Areas
Bahador Ghahramani

Crews on tankers traveling and hauling cargo on the lower reaches of the Mississippi River during the hot and humid (H&H) summer season face various occupational safety and ergonomics problems. Evaluation of medical data reveals that a large number of the crewmembers experience job related injuries, diseases, disorders, and exhaustion as a result of adverse environmental conditions (National Institute for Occupational Safety and Health [NIOSH], 1993). The accidents and injuries that occurred were characterized and then analysis was used to recommend constructive remedies and solutions. The results were also used to design and develop better work environments on the tankers and in the general industry.
 In H&H conditions, the body's chemical reactions constantly change in order to maintain the best possible reaction to changing environments. This chemical reaction increases blood flow to the skin through sweating. Body metabolism stabilizes body temperature through muscular work and convection, evaporation and radiation remove heat.