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Guide for the evaluation of human exposure to whole-body vibration
being built up from a limited set of elements and a few rules for combining them and that the production technique provided useful information about the nature of the elements and rules. Subjects employed several classes of elements performing syntactically different functions in their drawings. Although the experiments described may help to improve the standard of instructions, users will encounter difficulties even with the best instructions if telecommunications engineers fail to design systems which are easy to use.
Oct 1977, 7, 4 - 8 . Abstr in: Lighting Research and Technology. Open plan offices have led to the development of special furniture and, more recently, the incentive of energy conservation has led to the incorporation of lighting in this furniture. To study its effectiveness, a number of scale models have been produced. In one application where computer visual display units replace type-writers reflected glare problems are introduced from the inclined picture tubes.
10.2.28 (75806)
Workplace layout and equipment design
Smith, S.W., and Rea, M.S. Proofreading under different levels of illumination. Journal o f the illuminating Engineering Society, Oct 1978, 8.1, 4 7 - 5 2 .
10.2.26 (75781) Oldfield, D.E., Port, W.G., and Chisman, S.W. An investigation into possible back profiles for reclined seats in air-to-air combat aircraft. Royal Aircraft Establishment Flight Systems Department, Farnborough, Technical Report No TR 78013, Feb 1978. Abstr in: Royal Aircraft Estabhshment, Library List C.
The subjects' task in this experiment involved proofreading of paragraphs for misspelled words. Four young and four older subjects served in the experiment. It is concluded that age, print quality and illumination level significantly affect performance. Results indicate that performance improves with illumination and good print quality is more important for older subjects than for young subjects
Current interest in air-to-air combat has generated increased consideration of the use of a reclined seat as a means of improving the pilot's capability to withstand high g. However, it has recently been suggested that it might not be reasonable to design a seat in which the pilot needed to rest his head on a headrest for prolonged periods during normal flying. This report covers work on the profile of a reclined seat and an estimate of the probable improvement in relaxed grey-out threshold to be expected if the seat were designed so that the pilot was able to hold his head in a comfortable normal upright position without using a headrest. It was shown that a reclined seat designed in this way gave only minor improvement in relaxed grey-out threshold compared with a conventional upright seat, and the improvement was significantly less than had been found with seats in which the pilot needed to place his head on a headrest. These results point clearly to the need for serious consideration to be given to the headrest aspect of reclined seat design.
Noise 10.2.29 (75819) Cant, S.M. Noise dose assessment of the logging industry. American Industrial Hygiene Association Journal, Dec 1977, 3 8 . 1 2 , 7 2 6 - 7 3 0 . Abstr in: CIS Abstracts (CIS 78-822). A field survey was performed with yarders, log loaders, rubber tyred skidders, tractors, log trucks, rock drilling apparatus and chain saws. Noise dose exposures (measured by personal dosimetry) were 0' I - 13"9 (taking the noise dose standard recommended in the United States by the Occupational Safety and Health Administration (OSHA) as 1"0, that is, the equivalent to an exposure to 90 dBA for 8 h. The proposed OSHA action level of 0"5 was exceeded by the mean for each equipment category.
noise for some 15 years. Results confirm that empirical rules predicting exponential growth and recovery of temporary threshold shift during and after a work day apply in men who have significant permanent threshold shift from repeated exposure to the same noise for several years. 10.2.31 (75839)
Howell, R.W. A seven-year review of measured hearing levels in male manual steelworkers with high initial thresholds. British Journal o f Industrial Medicine, 1978, 35, 2 7 - 3 1 . Audiometric records of 449 male manual steelworkers were reviewed to see whether the hearing of men with high initial threshold levels deteriorated more rapidly than that of those men with more normal thresholds when exposed to similar noise levels. Subjects were between 15 and 54 years old at the time of the initial examination, and had a repeat audiogram 6 - 8 years later. They were classified into three occupational noise exposure groups: below 90 dB(A), 9 0 - 9 9 dB(A), and 100 dB(A) or over, without knowledge of their audiometric threshold levels, age, or aural history. Measurements at 0-5, l, 2, 3, 4 and 6 kHz for the right ear were considered, first as the mean for all six frequencies, then for 0"5, t and 2 kHz only, and finally for 6 kHz only. After standardisation for age, it was found that those in the high initial threshold groups deteriorated no faster than the remainder of the series. At the 9 0 - 9 9 dB(A) noise exposure level, X2 tests showed that the differences between the groups, in terms of mean measured hearing loss, were not significant at the 0"05 probability level. The age-standardised mean threshold shifts for the 0 " 5 - 6 kHz range of frequencies over the sevenyear review period were 7"5, 8.7 and 7-1 dB at a noise exposure level of 100 dB(A) or more, for workers with an initial threshold level of 12 dB, 1 2 - 2 6 dB and > 26 dB respectively; for those exposed to noise of 9 0 - 9 9 dB(A) the corresponding mean shifts were 7"8, 6.8 and 7"3 dB respectively; while for those exposed to noise of less than 90 dB(A) the mean shifts were 6"2, 5"0 and 5'2 dB respectively.
10.2.30 (75838)
Hetu, H., and Parrot, J.
Illumination 10.2.27 (75804)
Lemons, T.M., and Cole, J.M.
A field evaluation of noise-induced temporary threshold shift. A merican Industrial Hygiene Association Journal Apr 1978, 3 9 . 4 , 3 0 1 - 3 1 1 . Abstr in: CIS Abstracts (CIS 78-1279).
Scale models used to investigate office task lit systems furniture. Lighting Design an d A pplica tion,
116
AppliedErgonomics June 1979
Six hearing tests were performed on two consecutive days in nine brewery workers exposed to bottling
Vibration 10.2.32 (75850) International Organization for Standardization Guide for the evaluation of human exposure to whole-body vibration.
(In English, French.) The Organization, Geneva, Switzerland, International Standard ISO 2631-1978(E). Jan 1978, 15 pp. Abstr in: CIS Abstracts (CIS 78-1278). This international standard defines and gives numerical values for limits of exposure for vibrations transmitted from solid surfaces to the human body, in the frequency range 1 to 80 Hz. It may be apphed, within the specified lrequency range, to periodic vibrations and to random or nonperiodic vibrations with a distributed frequency spectrum. Provisionally, it may also be applied to continuous shock-type excitation in so far as the energy in question is contained within the 1 to 80 Hz band. An introduction is followed by sections devoted to: charactefisation of vibration exposure (direction of vibration, location of measurement, intensity of vibration, measuring equipment, random or broad-band vibration analysis, exposure time); vibration evaluation guide (fatigue, decreased proficiency boundary, reduced comfort boundary, health or safety exposure limit, evaluation of frequency spectrum, vibration in more than one direction simultaneously). Numerous tables and graphs.
10.2.33 (75851)
National Institute for Occupational Safety and Health Proceedings of the International Occupational Hand-Arm Vibration Conference. The Institute, Cincinnati, Ohio, USA, DHEW (NIOSH) Publication No 77-170, 1977, 253 pp. Abstr in: CIS Abstracts (CIS 78-681 ). Text of the papers to the conference ( 2 8 - 3 1 Oct 1975, Cincinnati, USA). Medical and physiological aspects (peripheral blood supply disturbances; occlusive arterial disease; vibration enhancement of blood-arterial wall macro-molecule transport; treatment of severe secondary Raynaud's disease: traumatic vasospastic disease in chain-saw operators; hygienic aspects of occupational hand-arm vibration (HAV), etc); epidemiological aspects (Longitudinal study of Raynaud's phenomenon in chain saw operators; vibration injury in rock drillers, etc; diagnostics and epidemiology of vibration disease and hearing impairment in m o t o r sawyers; finger-hand-arm-shoulder vibration syndrome in foundry workers; engineering and measurement (review of 3 years' HAV; evaluation of human exposure to hand-transmitted vibration; measuring vibration of hand-held pneumatic tools; measurement techniques for HAV; use of thermography in the diagnosis of HAV
the ANSI Z89 standards. The need for disease; measurement problems of the study of segmental vibration); progress protection against peripheral impacts in reduction of HAV in power saws in is discussed. Japan, Sweden, etc; FAO/ECE/ILO draft resolution on HAV for modern antivibration chain saws; recommendation 10.2.36 (75918) Smith, P.J., and Anderson, J.K. for medical monitoring). Alphabetical A proposal for the redesign of list of speakers. personal industrial protective equipment. In: Human Factors and Human Needs. 10.2,34 (75870) Proceedings of the Eleventh Annual Varkkila, M. Meeting of the Human Factors Grip force in vibration disease. Association of Canada, September Scandinavian Journal o f Work, 7 - 9 , 1978. Environment and Health, Jun 1978, The intent of this paper was to 4.2, 1 5 9 - 1 6 6 . investigate, define and correct a In this experiment the hand grip deficiency in the industrial force of 58 persons was measured. environment with respect to personal The study was carried out during a safety headgear. The deficiency was found to exist in the area of user compulsory health examination. The acceptability of the equipment available subjects compressed with their left at present. Specifically, by reducing hand for 5 min with fluctuating the weight and increasing the ease of maximal force and with the right use, while maintaining the performance, hand for 1 min with maximal utilization of the equipment will be constant force. The results were increased. It is expected that this will repeated with five different levels of result in significant savings in lostvibration and without vibration. time accidents. It was found that Individual forces varied in the 5 min substitution for the material used in experiment from 25 to 122 N. The the construction of the helmet's strongest subjects were in a group shell significantly decreased the weight affected by white finger, but with no of the equipment without decreasing claim of diminished grip force. The the performance of the helmet, and weakest forces were seen in the group subjectively most affected by vibration with only a minor cost penalty. At disease. On the basis of this the same time, the proposal features examination, it seems that in some modular components (such as eye, workers long-term exposure to face, hearing and breathing protectors) vibration causes a diminution in grip which may be attached to a hardhat force, which is a constant phenomenon, base to increase the ease of use of and it does not only manifest itself the equipment. This paper examines during their work. During exposure to general criteria required for a safety vibration the force reduced further helmet, sets its own specific design from the resting level among the criteria and presents alternative subjectively most affected lumbersolutions for integrated, modular jacks, but not in less affected groups safety headgear. or in the reference group. No vibration frequency was found to be especially 10.2.37 (75935) disadvantageous to grip force, and it Duncan, J.R., and Konz, S.A. was not possible to determine the Productivity in heat stress environments normal hmits of grip force. with personal dry-ice cooling. In: Proceedings of the 1976 Spring Annual AIIE Conference, 1976, pp 7 5 - 8 1 .
Specialised and protective clothing and equipment 10.2.35 (75911)
Cook, W.I., and Love, J.R. A report on the performance of miners' safety caps. National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHEW (NIOSH) Publication No 77-218, Aug 1977, 16 pp. Sixteen available models of miners' caps were evaluated and thirteen were found to be in comp.liance with the performance requirements of
A personal dry-ice cooling jacket developed to increase available productive time in industrial heat stress environments was evaluated in two industrial and two laboratory environments. A p r o t o t y p e design tested in a tyre manufacturing plant and a chemical manufacturing plant on six workers was successful in significantly reducing sweat loss by 30% and in providing cooling for over three hours while permitting the required task mobility. The laboratory evaluations were performed in drybulb temperatures of 35 and 45°C at 33 mm Hg water vapour pressure with two clothed men pedalling for 60 min. Mean heart rate throughout the 60 min exposure was 14 beats/rain less with
Applied Ergonomics June 1979
117
Oct 1977, 7, 4 - 8 . Abstr in: Lighting Research and Technology. Open plan offices have led to the development of special furniture and, more recently, the incentive of energy conservation has led to the incorporation of lighting in this furniture. To study its effectiveness, a number of scale models have been produced. In one application where computer visual display units replace type-writers reflected glare problems are introduced from the inclined picture tubes.
10.2.28 (75806)
Workplace layout and equipment design
Smith, S.W., and Rea, M.S. Proofreading under different levels of illumination. Journal o f the illuminating Engineering Society, Oct 1978, 8.1, 4 7 - 5 2 .
10.2.26 (75781) Oldfield, D.E., Port, W.G., and Chisman, S.W. An investigation into possible back profiles for reclined seats in air-to-air combat aircraft. Royal Aircraft Establishment Flight Systems Department, Farnborough, Technical Report No TR 78013, Feb 1978. Abstr in: Royal Aircraft Estabhshment, Library List C.
The subjects' task in this experiment involved proofreading of paragraphs for misspelled words. Four young and four older subjects served in the experiment. It is concluded that age, print quality and illumination level significantly affect performance. Results indicate that performance improves with illumination and good print quality is more important for older subjects than for young subjects
Current interest in air-to-air combat has generated increased consideration of the use of a reclined seat as a means of improving the pilot's capability to withstand high g. However, it has recently been suggested that it might not be reasonable to design a seat in which the pilot needed to rest his head on a headrest for prolonged periods during normal flying. This report covers work on the profile of a reclined seat and an estimate of the probable improvement in relaxed grey-out threshold to be expected if the seat were designed so that the pilot was able to hold his head in a comfortable normal upright position without using a headrest. It was shown that a reclined seat designed in this way gave only minor improvement in relaxed grey-out threshold compared with a conventional upright seat, and the improvement was significantly less than had been found with seats in which the pilot needed to place his head on a headrest. These results point clearly to the need for serious consideration to be given to the headrest aspect of reclined seat design.
Noise 10.2.29 (75819) Cant, S.M. Noise dose assessment of the logging industry. American Industrial Hygiene Association Journal, Dec 1977, 3 8 . 1 2 , 7 2 6 - 7 3 0 . Abstr in: CIS Abstracts (CIS 78-822). A field survey was performed with yarders, log loaders, rubber tyred skidders, tractors, log trucks, rock drilling apparatus and chain saws. Noise dose exposures (measured by personal dosimetry) were 0' I - 13"9 (taking the noise dose standard recommended in the United States by the Occupational Safety and Health Administration (OSHA) as 1"0, that is, the equivalent to an exposure to 90 dBA for 8 h. The proposed OSHA action level of 0"5 was exceeded by the mean for each equipment category.
noise for some 15 years. Results confirm that empirical rules predicting exponential growth and recovery of temporary threshold shift during and after a work day apply in men who have significant permanent threshold shift from repeated exposure to the same noise for several years. 10.2.31 (75839)
Howell, R.W. A seven-year review of measured hearing levels in male manual steelworkers with high initial thresholds. British Journal o f Industrial Medicine, 1978, 35, 2 7 - 3 1 . Audiometric records of 449 male manual steelworkers were reviewed to see whether the hearing of men with high initial threshold levels deteriorated more rapidly than that of those men with more normal thresholds when exposed to similar noise levels. Subjects were between 15 and 54 years old at the time of the initial examination, and had a repeat audiogram 6 - 8 years later. They were classified into three occupational noise exposure groups: below 90 dB(A), 9 0 - 9 9 dB(A), and 100 dB(A) or over, without knowledge of their audiometric threshold levels, age, or aural history. Measurements at 0-5, l, 2, 3, 4 and 6 kHz for the right ear were considered, first as the mean for all six frequencies, then for 0"5, t and 2 kHz only, and finally for 6 kHz only. After standardisation for age, it was found that those in the high initial threshold groups deteriorated no faster than the remainder of the series. At the 9 0 - 9 9 dB(A) noise exposure level, X2 tests showed that the differences between the groups, in terms of mean measured hearing loss, were not significant at the 0"05 probability level. The age-standardised mean threshold shifts for the 0 " 5 - 6 kHz range of frequencies over the sevenyear review period were 7"5, 8.7 and 7-1 dB at a noise exposure level of 100 dB(A) or more, for workers with an initial threshold level of 12 dB, 1 2 - 2 6 dB and > 26 dB respectively; for those exposed to noise of 9 0 - 9 9 dB(A) the corresponding mean shifts were 7"8, 6.8 and 7"3 dB respectively; while for those exposed to noise of less than 90 dB(A) the mean shifts were 6"2, 5"0 and 5'2 dB respectively.
10.2.30 (75838)
Hetu, H., and Parrot, J.
Illumination 10.2.27 (75804)
Lemons, T.M., and Cole, J.M.
A field evaluation of noise-induced temporary threshold shift. A merican Industrial Hygiene Association Journal Apr 1978, 3 9 . 4 , 3 0 1 - 3 1 1 . Abstr in: CIS Abstracts (CIS 78-1279).
Scale models used to investigate office task lit systems furniture. Lighting Design an d A pplica tion,
116
AppliedErgonomics June 1979
Six hearing tests were performed on two consecutive days in nine brewery workers exposed to bottling
Vibration 10.2.32 (75850) International Organization for Standardization Guide for the evaluation of human exposure to whole-body vibration.
(In English, French.) The Organization, Geneva, Switzerland, International Standard ISO 2631-1978(E). Jan 1978, 15 pp. Abstr in: CIS Abstracts (CIS 78-1278). This international standard defines and gives numerical values for limits of exposure for vibrations transmitted from solid surfaces to the human body, in the frequency range 1 to 80 Hz. It may be apphed, within the specified lrequency range, to periodic vibrations and to random or nonperiodic vibrations with a distributed frequency spectrum. Provisionally, it may also be applied to continuous shock-type excitation in so far as the energy in question is contained within the 1 to 80 Hz band. An introduction is followed by sections devoted to: charactefisation of vibration exposure (direction of vibration, location of measurement, intensity of vibration, measuring equipment, random or broad-band vibration analysis, exposure time); vibration evaluation guide (fatigue, decreased proficiency boundary, reduced comfort boundary, health or safety exposure limit, evaluation of frequency spectrum, vibration in more than one direction simultaneously). Numerous tables and graphs.
10.2.33 (75851)
National Institute for Occupational Safety and Health Proceedings of the International Occupational Hand-Arm Vibration Conference. The Institute, Cincinnati, Ohio, USA, DHEW (NIOSH) Publication No 77-170, 1977, 253 pp. Abstr in: CIS Abstracts (CIS 78-681 ). Text of the papers to the conference ( 2 8 - 3 1 Oct 1975, Cincinnati, USA). Medical and physiological aspects (peripheral blood supply disturbances; occlusive arterial disease; vibration enhancement of blood-arterial wall macro-molecule transport; treatment of severe secondary Raynaud's disease: traumatic vasospastic disease in chain-saw operators; hygienic aspects of occupational hand-arm vibration (HAV), etc); epidemiological aspects (Longitudinal study of Raynaud's phenomenon in chain saw operators; vibration injury in rock drillers, etc; diagnostics and epidemiology of vibration disease and hearing impairment in m o t o r sawyers; finger-hand-arm-shoulder vibration syndrome in foundry workers; engineering and measurement (review of 3 years' HAV; evaluation of human exposure to hand-transmitted vibration; measuring vibration of hand-held pneumatic tools; measurement techniques for HAV; use of thermography in the diagnosis of HAV
the ANSI Z89 standards. The need for disease; measurement problems of the study of segmental vibration); progress protection against peripheral impacts in reduction of HAV in power saws in is discussed. Japan, Sweden, etc; FAO/ECE/ILO draft resolution on HAV for modern antivibration chain saws; recommendation 10.2.36 (75918) Smith, P.J., and Anderson, J.K. for medical monitoring). Alphabetical A proposal for the redesign of list of speakers. personal industrial protective equipment. In: Human Factors and Human Needs. 10.2,34 (75870) Proceedings of the Eleventh Annual Varkkila, M. Meeting of the Human Factors Grip force in vibration disease. Association of Canada, September Scandinavian Journal o f Work, 7 - 9 , 1978. Environment and Health, Jun 1978, The intent of this paper was to 4.2, 1 5 9 - 1 6 6 . investigate, define and correct a In this experiment the hand grip deficiency in the industrial force of 58 persons was measured. environment with respect to personal The study was carried out during a safety headgear. The deficiency was found to exist in the area of user compulsory health examination. The acceptability of the equipment available subjects compressed with their left at present. Specifically, by reducing hand for 5 min with fluctuating the weight and increasing the ease of maximal force and with the right use, while maintaining the performance, hand for 1 min with maximal utilization of the equipment will be constant force. The results were increased. It is expected that this will repeated with five different levels of result in significant savings in lostvibration and without vibration. time accidents. It was found that Individual forces varied in the 5 min substitution for the material used in experiment from 25 to 122 N. The the construction of the helmet's strongest subjects were in a group shell significantly decreased the weight affected by white finger, but with no of the equipment without decreasing claim of diminished grip force. The the performance of the helmet, and weakest forces were seen in the group subjectively most affected by vibration with only a minor cost penalty. At disease. On the basis of this the same time, the proposal features examination, it seems that in some modular components (such as eye, workers long-term exposure to face, hearing and breathing protectors) vibration causes a diminution in grip which may be attached to a hardhat force, which is a constant phenomenon, base to increase the ease of use of and it does not only manifest itself the equipment. This paper examines during their work. During exposure to general criteria required for a safety vibration the force reduced further helmet, sets its own specific design from the resting level among the criteria and presents alternative subjectively most affected lumbersolutions for integrated, modular jacks, but not in less affected groups safety headgear. or in the reference group. No vibration frequency was found to be especially 10.2.37 (75935) disadvantageous to grip force, and it Duncan, J.R., and Konz, S.A. was not possible to determine the Productivity in heat stress environments normal hmits of grip force. with personal dry-ice cooling. In: Proceedings of the 1976 Spring Annual AIIE Conference, 1976, pp 7 5 - 8 1 .
Specialised and protective clothing and equipment 10.2.35 (75911)
Cook, W.I., and Love, J.R. A report on the performance of miners' safety caps. National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHEW (NIOSH) Publication No 77-218, Aug 1977, 16 pp. Sixteen available models of miners' caps were evaluated and thirteen were found to be in comp.liance with the performance requirements of
A personal dry-ice cooling jacket developed to increase available productive time in industrial heat stress environments was evaluated in two industrial and two laboratory environments. A p r o t o t y p e design tested in a tyre manufacturing plant and a chemical manufacturing plant on six workers was successful in significantly reducing sweat loss by 30% and in providing cooling for over three hours while permitting the required task mobility. The laboratory evaluations were performed in drybulb temperatures of 35 and 45°C at 33 mm Hg water vapour pressure with two clothed men pedalling for 60 min. Mean heart rate throughout the 60 min exposure was 14 beats/rain less with
Applied Ergonomics June 1979
117