Occupational Ergonomics - Volume 8, issue 4

Authors: Kluth, Karsten | Strasser, Helmut

Article Type: Editorial

DOI: 10.3233/OER-2009-0164

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 133-134, 2009

Authors: Penzkofer, Mario | Kluth, Karsten | Strasser, Helmut

Article Type: Research Article

Abstract: Due to increasing sales numbers, the production and distribution of frozen food, as well as working in the deep cold, are becoming more and more important. Nevertheless, there are only a few investigations into the effects of working in the cold on humans. Order-picking in a cold environment at approximately −24°C represents a high workload and even when wearing suitable cold protective clothing leads to exceptionally high strain. At least hypothetically, also varying physical strain of younger and older employees could be expected. Therefore, evaluation methods were developed and applied for the quantification of the physiological responses of two age-groups …to working in the cold. The results of heart rate measurements while working at +3°C and −24°C are presented. Show more

Keywords: Physiological field study, working in severe cold, age-adjusted strain, heart rate

DOI: 10.3233/OER-2009-0165

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 135-145, 2009

Authors: Kluth, Karsten | Penzkofer, Mario | Strasser, Helmut

Article Type: Research Article

Abstract: It has not yet been established whether an age-related organization of the work and rest times for order-pickers working in deep cold-storage depots with chill room and cold store is necessary or not. In order to assess the physical effects of order-picking of cold food at about +3°C and of frozen food at about −24°C, 30 male subjects (Ss) were classified into two age groups (20- to 35-year-olds and 40- to 65-year-olds). Their body core temperature was taken every 15 min at the tympanum, and the skin temperature was measured at several positions during whole-day working shifts. The discontinuously registered …temperature at the tympanum yielded a decrease of up to 1.5K in the case of the younger Ss and of up to 2.2K for the older Ss in comparison to the value at the outset. A complete warming-up during the breaks was often not possible. The slight falling of the core temperature during the work in the cold store, measured for both age groups to a different extent, could be compensated by all Ss during the breaks. There were no age-related differences in the results of the measured skin temperatures. Significantly lower temperatures were recorded merely at the nose as well as at the fingers and the toes when working in the cold store. The work in the chill room can be considered as unproblematic. Show more

Keywords: Work physiological field study, age, cold exposure, core temperature, skin temperature, manual material handling

DOI: 10.3233/OER-2009-0166

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 147-157, 2009

Authors: Schneider, Joerg | Ermert, Andreas | Strasser, Helmut

Article Type: Research Article

Abstract: In order to optimize the illumination of industrial visual testing and inspection workplaces, the limits of the detectability of 3-dimensional details have to be determined for different surfaces and lighting scenarios. For this reason, the influence of the inclination of samples on luminance and contrast was examined, and additionally laboratory tests were carried out to measure visual acuity when detecting flaws on the surfaces of different materials at various illuminations. The results were compared to the subjective assessment of test subjects (Ss) who participated in the laboratory tests. It turned out that all results are strongly dependent on the inclination …of the samples rather than on the lighting scenarios applied. Show more

Keywords: Inspections tasks, lighting condition, visual acuity, ergonomic evaluation

DOI: 10.3233/OER-2009-0170

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 159-169, 2009

Authors: Kampmann, Bernhard | Bresser, Georg | Schütte, Martin

Article Type: Research Article

Abstract: Four mine rescue brigadesmen performed three different standardized trainings in uncompensable heat stress with different equipment, clothing and climatic stress. The strain during these trainings may be considered as typical for training and missions of firemen, mine rescue brigadesmen and subjects working under protective clothing. – During ten years the diverse trainings were repeated. Heart rates and body temperatures were recorded throughout the exposures. A significant linear trend over time only was found for body mass (increase in three of the subjects). Specific physical fitness (fitness per body mass) as well as heart rate or body temperature showed no significant …trend over time for initial or final values. The variability of the physiological strain is described in good approximation by normal distributions and shows quite a high magnitude. On base of the whole data set inter-individual components of variance are estimated by a 2-factorial ANOVA (person, time of measurement) with the factor time of measurement nested under the factor person. Confidence intervals for the estimated mean values and respectively, the calculation of the required number of measurements for a given confidence interval are determined by performing a two factorial ANOVA with both factors fully crossed. Show more

Keywords: Intra-individual variability, inter-individual variability, heart rate, body temperature, heat stress

DOI: 10.3233/OER-2009-0169

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 171-183, 2009

Authors: Bröde, Peter | Schütte, Martin | Kampmann, Bernhard | Griefahn, Barbara

Article Type: Research Article

Abstract: Acclimation as an adaptive response of the human body to repeatedly occurring heat stress causes a reduction of core temperature (Tco) and heart rate (HR) at the end of heat exposure. The analysis of three acclimation series (WBGT =33.5°C) showed that the lowering of Tco and HR occurred already in the resting period preceding heat stress. The lowered resting values accounted for a substantial part of the beneficial effects of acclimation and may be mainly induced by the physical exercise, as a similar reduction of resting values was also observed under thermally neutral conditions. Expanding the database with short-term acclimation …series revealed that the resting values were less reduced for females compared to males, but that the same relations between resting and final Tco and HR existed. The results further suggest that the reduction of resting Tco reflects long term effects of adaptation whereby the resting HR also depends on unspecific situational influences. The lowering of the initial values might be a suitable instrument when considering the effects of acclimation in thermoregulatory models for the assessment of heat stress at the workplace. Show more

Keywords: Heat stress, acclimation, exercise, cardiac strain, body-temperature

DOI: 10.3233/OER-2009-0168

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 185-193, 2009

Authors: Gebhardt, Hansjürgen | Kampmann, Bernhard | Müller, Bernd Hans | Bux, Kersten

Article Type: Research Article

Abstract: The present article summarizes essential results of the research project ``Testing of the application of the Predicted-Heat-Strain-(PHS-)model for the design of work-rest-cycles while working in hot environment'' which has been executed on behalf of the Federal Institute for Occupational Safety and Health (BAuA). A pragmatic proposal has been tested on the basis of laboratory experiments and model calculations using the PHS-Model according to ISO 7933. The results show, that the pragmatic proposal could be verified either by physiological measurements and also by the PHS-Model. A procedure to calculate required cooling phases is presented. Based on the results, a guideline is …presented, which may be used for the design of work-rest-cycles for work in hot environments. Show more

Keywords: Work-rest cycles, PHS-Model, working in warm and hot environments, model calculations

DOI: 10.3233/OER-2009-0167

Citation: Occupational Ergonomics, vol. 8, no. 4, pp. 195-204, 2009