Heat and cold - 949 entries found
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Health and Safety Executive
LD50 equivalent for the effect of thermal radiation on humans
This study extends a previous literature review undertaken to assess the current status of the modelling of the effects of thermal radiation from hydrocarbon fires. This review suggested that the 'Dangerous Dose' criterion of 1000(kW/m2)4/3s for an average population is a reasonable estimate of the thermal dose at which serious burns may be received or a small percentage of the population may die. The current study discusses the thermal dose level which would be suitable for use as a 'Lethal Dose' (LD50) equivalent and puts forward an estimated value of approximately 2000(kW/m2)4/3s. Assumptions and uncertainties in the estimation are discussed.
HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, 1997. iii, 25p. Illus. 33 ref. Price: GBP 15.00.
Chen Y.T., Constable S.H., Bomalaski S.H.
A lightweight ambient air-cooling unit for use in hazardous environments
A compact battery-powered beltpack cooling unit was developed to deliver filtered ambient air to the face and body. The device was tested on seven subjects wearing chemical protective clothing who performed exercises in a thermally controlled chamber under different experimental conditions. Intermittent cooling (air conditioned cooling during rest periods but no personal cooling during work cycles) and continuous air cooling (personal cooling during work cycles and conditioned air cooling during rest periods) resulted in significant reductions in rectal temperature, mean skin temperature, and heart rate compared with the no-cooling conditions. The continuous air-cooling trial significantly improved thermal comfort and sweat evaporation.
American Industrial Hygiene Association Journal, Jan. 1997, Vol.58, No.1, p.10-14. Illus. 10 ref.
Nag P.K., Bandyopadhyay P., Ashtekar S.P., Kothari D., Desai H., Nag A.
Human work capacity under combined stress of work and heat
The working capacity of young, healthy, unacclimatized men (N= 11) was studied under long-duration (8 to 9 days) exposure to combined work and heat (dry and humid). The average heat exposure time for group A was higher than for group B, but group B sustained a high heat load as reflected in the high deep-body temperature maintained during the exposure. The high body temperature load of group B had a significant effect on the cardiorespiratory capacity, indicating an upward trend in maximal oxygen uptake. This was significant for the first four days of exposure. Subjects of group B had a relatively higher working capacity compared to those in group A on all days. The maximal oxygen intake and analysis of the fractions of oxygen debt contraction indicated that the subjects showed a better training/heat acclimatization effect under hot, humid conditions. Topics: assessment of physical capacity; body temperature; climate chamber studies; ergometric tests; heat load; hot workplaces; oxygen consumption monitoring; physical workload; synergism; work capacity.
Journal of Human Ergology, Dec. 1996, Vol.25, No.2, p.105-113. Illus. 14 ref.
Ben Lallahom L., Akrout M., Sayadi A., Hidri A., Karoai F., Zouiter I., Kraiem R., Maaloul A., Benammar R.
Small-scale brickworks in Tunisia: Exposure to hot workplaces
Briqueteries artisanales en Tunisie: le travail à la chaleur [in French]
Topics: brick and tile industry; cross-sectional study; ergonomics; handicrafts; heat load; hot workplaces; pulse rate; questionnaire survey; small enterprises; statistical aspects; Tunisia; WBGT index.
SST - Santé et Sécurité au Travail, Oct. 1996, No.1, p.26-31.
Toftum J., Nielsen R.
Impact of metabolic rate on human response to air movements during work in cool environments
Oxygen consumption was monitored in ten men exposed to a range of air velocities and air temperatures while performing standing physical work at two different activity levels. The neck was identified as the most draught sensitive area. While air temperature influenced draught ratings at the hands and face, the percentage of dissatisfied subjects due to draught at the head region did not depend on the air temperature. Working at a high activity level resulted in fewer dissatisfied persons, compared to a low activity level. The metabolic rate, equivalent to the internal heat production, significantly influenced human response to air movements.
International Journal of Industrial Ergonomics, 1996, Vol.18, p.307-316. Illus. 30 ref.
Deurer W., et al.
Improvement of working conditions, safety and health in monumental masonry using masons restoring cathedrals as examples
Verbesserung der Arbeitsbedingungen sowie des Arbeits- und Gesundheitsschutzes für Steinmetzbetriebe am Beispiel einer Dombauhütte [in German]
The dust and noise levels as well as the work postures of monumental masons were determined on several workplaces in Germany. In addition, the air temperatures, humidity and illumination levels were measured. Optimized designs of the workplace and illumination are illustrated. Measures to reduce dust and noise exposure are described in detail.
Wirtschaftsverlag NW, Postfach 101110, 27511 Bremerhaven, Germany, 1996. 231p. Illus. 125 ref. Price: DM 38.50.
Griefahn B., Bröde P., Forsthoff A.
On the physiological response to work in a moderately cold environment
Zur thermophysiologischen Situation von Beschäftigten in mässiger Kälte [in German]
The skin temperature on the chest, upper and lower back remained in the comfortable range and the rectal temperature of 6 female and 33 male workers of the food industry remained unaffected by work in temperatures between 0 and 15°C. The insulating clothing worn by the workers had a higher thermal insulation than required by the standard ISO TR 11079. It ranged between 0.7 and 2.3clo. The energy metabolism varied between 99 and 242W/m2. Hand and feet remained below the comfortable range throughout the shift during which the measurements were taken. It is recommended to study the connection of repeated cooling of the extremities with the prevalence of certain diseases such as Raynaud's phenomenon.
Arbeitsmedizin - Sozialmedizin - Umweltmedizin, Apr. 1996, Vol.31, No.4, p.168-174. Illus. 14 ref.
Gimpel S., Umbach K.H.
Cold-protective clothing and what to wear underneath?
Kälteschutzkleidung und was darunter? [in German]
Thermal insulation and evaporative resistance of underwear and shirts made of 10 different materials were measured. In addition, the parameters determining the skin comfort of underwear were measured. The underwear and shirts made of materials that yielded the best results where used in tests with insulating clothing, in order to find the best cold-protective ensemble. Four different combinations of underwear, shirts and insulating overalls were studied. The length of time during which the ensembles can be worn in an environment of -30°C and 50% relative humidity was determined. The data are provided in a table as a function of energy metabolism.
Sicherheitsingenieur, Mar. 1996, Vol.27, No.3, p.24-29. Illus. 5 ref.
Shinohara M., Kiyota N.
On the method for estimating the metabolic heat of office work
Jimu sagyō ji no taisha netsuryō no yosoku hōhō ni kansuru kenkyū [in Japanese]
Office work in a college office, a construction company and gymnastic facilities was videotaped. From these tapes, the office work in each site was examined and analyzed. Some 36 different body actions were observed in the office work at these sites. Each of the various body actions were of short duration. Empirical equations for transient metabolic heat were deduced from the beginning of a movement to the end. A method was proposed for estimating the metabolic heat of the office personnel, considering the situation of successive movements in a short time, based on the metabolic heat of each movement, empirical equations and the duration of movements. Experimented values were compared with calculated values. The mean value of metabolic heat obtained by a time weighting method could yield significant error in comparison with the proposed method.
Transactions of the Society of Heating, Air-conditioning and Sanitary Engineers of Japan, 25 July 1996, No.62, p.13-22. Illus. 9 ref.
Gazey C., Bates G., Matthew B.
Fluid loss and replacement in petroleum workers from the north west of Western Australia
Fluid loss, fluid intake, heart rate, and work rate (% physical capacity) were recorded for seven petroleum exploration workers in Western Australia. In relatively mild environmental conditions over two days, the average fluid loss was 434mL/h, fluid intake 466mL/h, and workrate 22%. Only three workers consistently replaced their fluid losses over the study period. Recommendations for the prevention of heat illness include adequate fluid replacement strategies to minimize the risk of hyperthermia, appropriate work-rest patterns, and worker education.
Journal of Occupational Health and Safety - Australia and New Zealand, Aug. 1996, Vol.12, No.4, p.457-461. 11 ref.
Work in a hot environment
Travail à la chaleur [in French]
Contents of this information note: extent of the problem (16% of French manual workers complained of the heat in a survey conducted in 1986); thermal balance; relevant standards (ISO 7726, 8996, 9920, 7730, 7243, 7933, 9886); measurement of basic parameters; heat indexes; hot environments (WBGT index, the Sweating Index SWreq); measurement strategies.
Encyclopédie médico-chirurgicale, Toxicologie-Pathologie professionnelle, 2nd Quarter 1996, No.111, 4p. Illus. 12 ref.
Smith D.L., Petruzzello S.J., Kramer J.M., Misner J.E.
Physiological, psychophysical, and psychological responses of firefighters to firefighting training drills
Fifteen firefighters wearing full firefighting gear performed two firefighting tasks (advancing fire hose, chopping wood) inside a training structure containing live fires. Measurements of heart rate, temperature and blood lactate and perceptions of psychophysical and psychological variables suggest that the tasks used in this study impose considerable physiological, psychophysical and psychological strain. The combination of physical exertion in full protective gear and at high thermal heat loads led to near maximal heart rate and elevated temperatures after only 16min of activity. Verbal responses appeared to underestimate the physiological stress of the body.
Aviation, Space, and Environmental Medicine, Nov. 1996, Vol.67, No.11, p.1063-1068. 22 ref.
Reneau P.D., Bishop P.A.
Validation of a personal heat stress monitor
This study is an evaluation of the validity of a personal heat strain monitor in predicting body-core temperature. The rational basis for development of such a monitor is due to the large interindividual variability of workers' responses to heat and because working in heat is hard to manage safely, taking also into account differences in the protective suits. The results are that the validated monitor underestimates rectal temperature prediction for both vapour permeable and vapour barrier suits, but with the latter clothing it is more effective in alerting workers to incipient danger.
American Industrial Hygiene Association Journal, July 1996, Vol.57, No.7, p.650-657. Illus. 22 ref.
Essential acquired cold urticaria: Stimulated only by systemic as well as local cooling
A food processing worker with a long history of eczema developed acute urticarial rash on the face following work in a chilled part of the factory during a spell of cold weather. A cold provocation test resulted in a pronounced urticarial rash. At warmer ambient temperatures, there was no reaction to the cold provocation test and the facial rash had improved. The report illustrates a case of essential acquired cold urticaria in which systemic cooling was necessary to produce a reaction to local cold provocation.
Occupational Medicine, Apr. 1996, Vol.46, No.2, p.157-158. 9 ref.
Dellinger A.M., Kachur S.P., Sternberg E., Russell J.
Risk of heat-related injury to disaster relief workers in a slow-onset flood disaster
Analysis of medical claims filed by disaster relief workers in the State of Illinois (USA) following the 1993 floods indicated that the most frequently reported injury was heat-related injury or illness. Workers involved in sandbagging activities were exposed to high ambient temperatures, high humidity and prolonged exertion, all of which can contribute to heat-related injury. Basic prevention guidelines include a balanced work-rest schedule, easily accessible drinking water, acclimatization to work activities, and early recognition and treatment of heat-related symptoms.
Journal of Occupational and Environmental Medicine, July 1996, Vol.38, No.7, p.689-692. 15 ref.
Griefahn B., Forsthoff A., Bröde P.
Heart rates, rectal and skin temperatures recorded during work in moderate cold
Heart rates and rectal and skin temperatures were continuously recorded for three groups of food industry employees working in air temperatures of 0-7°C, 13-15°C or moving frequently between these temperatures. The three groups differed only with regard to temperatures of the skin directly exposed to cold air, particularly the fingers. Temperature declines at the fingers and subsequent rewarming times were inversely related to average air temperatures. Since cold-induced vasoconstrictions probably constitute a risk for Raynaud's phenomenon, adequate protection of the hands against cold is required.
Central European Journal of Occupational and Environmental Medicine, 1996, Vol.2, No.2, p.146-157. 18 ref.
Air-conditioned storage of hydrofluoric acid
Stockage climatisé pour l'acide fluorhydrique [in French]
Description of the changes made in the operation and maintenance of a hydrofluoric acid (HF) storage facility in France. Originally, the facility was an open-air one, in order to reduce the risk of HF leakage and its eventual effects on the environment. Main features of the change: maintenance of storage temperature below the boiling point of HF, reduction of pressure in the storage tanks, reduction in the diameter of the pipes. The whole of the storage facility, storage tanks and pumping equipment included, is enclosed in a thermally isolated building with air-conditioning that maintains the ambient temperature at a constant +5°C. Because of the risk of projectiles/splashes, sensitive points are enclosed in protective polycarbonate cages, while the long-distance manual valve controls are placed just outside these cages.
Travail et sécurité, May 1996, No.548, p.2-5. Illus.
Griefahn B., Künemund C., Neffgen H., Sommer S.
Human adaptation to work in two different climates
The processes of acclimatization to a hot-dry climate and to a warm-humid climate were studied with reference to changes in heart rate, rectal temperature and sweat loss. Recalculation of previously published data from 62 experiments together with results of a laboratory acclimatization study revealed that these physiological functions behaved similarly in each climate. Results suggest that the wet bulb globe temperature, which was the same in each climate, is a suitable measure of heat stress for industrial purposes.
International Journal of Occupational Safety and Ergonomics, 1996, Vol.2, No.1, p.60-73. 46 ref.
Hymes I., Boydell W., Prescott B.
Thermal radiation: Physiological and pathological effects
This report presents data on the effects of thermal radiation for use in the assessment of hazards from fires and fireballs. Contents: general effects of fires and fireballs and physiological implications; basic principles of thermal radiation and effects on man; properties and biological role of skin; pathological damage from thermal radiation; prognosis of burn injury victims; application of burn data to thermal radiation hazard situations; significance of clothing in exposure to thermal radiation; ignition and melting characteristics of clothing fabrics; nature of burn injury from burning clothing; attenuation and mitigation of thermal radiation.
Institution of Chemical Engineers, Davis Building, 165-189 Railway Terrace, Rugby CV21 3HQ, United Kingdom, 1996. vii, 130p. Illus. 57 ref. Index. Price: GBP 30.00.
Reneau P.D., Bishop P.A.
A review of the suggested wet bulb globe temperature adjustment for encapsulating protective clothing
A review is presented of research relevant to the American Conference of Governmental Industrial Hygienists' (ACGIH) suggested wet bulb globe temperature (WBGT) adjustment to threshold limit values (TLV) for workers in vapour barrier encapsulative protective clothing. This adjustment was recommended to be 10° according to the 1990 ACGIH guidelines but was not included in the 1991 guidelines. Six studies were reviewed comparing heart rate and rectal temperature increase over time. Findings support the suggested WBGT TLV adjustment of 10° when wearing encapsulating protective clothing.
American Industrial Hygiene Association Journal, Jan. 1996, Vol.57, No.1, p.58-61. 10 ref.
Thonneau P., Ducot B., Bujan L., Mieusset R., Spira A.
Heat exposure as a hazard to male fertility
This brief communication describes the results of a questionnaire survey of 522 French women who gave birth to a child between June and October 1992. The questionnaire included questions about the father's working conditions around the time of conception. Couples where the father was occupationally exposed to heat or seated in a vehicle for more than three hours per day at work had longer times to pregnancy than a reference group. Results are consistent with the hypothesis that professional exposure to heat is a risk factor for male fertility.
Lancet, 20 Jan. 1996, Vol.347, No.8995, p.204-205. Illus. 4 ref.
Rew P.J., Hulbert W.G.
Health and Safety Executive
Development of pool fire thermal radiation model
Recent developments in modelling the effects of external radiation from pool fires were reviewed and relevant improvements were incorporated into the current HSE (POOLFIRE5) model. Software for the improved model (POOLFIRE6) was developed and validated. The model incorporates correlations for calculating the radiation from the pool surface in two zones: a high emissive power, clean burning layer at the base with a smoky, obscured layer above. A detailed technical specification of the new model is presented along with validation results and an illustration of its use for a typical scenario.
HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, 1996. iv, 99p. Illus. 85 ref. Price: GBP 20.00.
Physical factors in the indoor environment
Physical factors in the non-industrial indoor environment that affect human health, comfort, productivity, and well-being are reviewed. Topics covered include: thermal comfort (environmental variables, activity and clothing levels, building design considerations, humidity); noise and vibration; light and other electromagnetic radiation (lighting design, health effects, ultraviolet radiation); combined effects and sick building syndrome.
Occupational Medicine: State of the Art Reviews, Jan.-Mar. 1995, Vol.10, No.1, p.59-94. Illus. 78 ref.
Erba P., Siracusa S., Tommasini R.
Experimental investigation into the behaviour of differential switches
Indagini sperimentali sul comportamento di interruttori differenziali [in Italian]
Report on an investigation of 144 differential switches under different kinds of environmental conditions (hot and dry, hot and humid, rapid temperature change, cold, saline mist). Large differences were found in the occurrence of interruptor failure between different models and under different environmental conditions.
Prevenzione oggi, Jan.-June 1995, Vol.7, No.1-2, p.157-184. Illus.
Gräff B., Hubert K., Zoller H.J.
Bundesanstalt für Arbeitsschutz
Study on air velocities and air temperatures in industrial workplaces
Untersuchungen von Luftgeschwindigkeiten und Lufttemperaturen an industriellen Arbeitsplätzen [in German]
Air temperature, air velocity and relative humidity were measured at various locations in 11 industrial plants. The measurements were taken at 0.1, 1.1 and 1.7m above the ground. In all cases the values for air turbulence and air temperatures were in the acceptable range. Industrial plants studied included manufacturers of ventilation and air conditioning systems, a large truck assembly plant, a manufacturer of electronic components, a boiler manufacturer, a company producing punched metal products and chemical plants producing household products.
Wirtschaftsverlag NW, Verlag für neue Wissenschaft GmbH, Postfach 10 11 10, 27511 Bremerhaven, Germany, 1995. 188p. Illus. 8 ref.
Fitzgerald D.A., Heagerty A.H.M., English J.S.C.
Cold urticaria as an occupational dermatosis
A 45-year-old female pottery worker presented with a six-month history of intermittent swelling and itching of the hands. This generally occurred during the course of her work as a lithographer, which consisted of manually immersing transfers in a cold solution and applying them to pieces of finished pottery. She had no history of skin disease. Examination was initially unremarkable, but application of an ice cube wrapped in a polyethylene bag to the forearm for two minutes resulted in a pronounced urticaria weal, which persisted for approximately 30min and was accompanied by intense pruritus. Cold urticaria should be considered as a skin disease of potentially occupational origin.
Contact Dermatitis, Apr. 1995, Vol.32, No.4, p.238. 7 ref.
Freezing installations - Biting and truly "cool"
Plattenfroster - ätzend und echt cool [in German]
Freezers used in the meat industry to deep-freeze meat require ammonia as refrigerant. Because ammonia is caustic and explosive, rooms containing meat freezers need to be equipped with sprinklers. The water mist produced by the sprinklers binds and dilutes accidentally released ammonia. The emergency exit may at no point be further away than 20m. In rooms in which more than 100kg ammonia are in use as the refrigerant at least 2 self-contained respirators and 2 protective overalls need to be readily available at all times. Employees need to be informed about the hazards posed by ammonia. In addition, employees need to be protected from the cold and moisture by the wearing of protective gloves and shoes and from lifting and carrying heavy loads by the use of elevating platforms. Anti-slip floors are needed to prevent falls.
FBG-Forum, Feb. 1995, No.1, p.6-7. Illus. 6 ref.
Maurer S., Seubert A., Seubert S., Fuchs T.
Contact dermatitis from textiles
Kontaktallergie auf Textilien [in German]
Between April 1992 and April 1994, 26 patients with contact dermatitis were subjected to patch tests with selected textile chemicals. Of the 26 patients, 21 were women aged 23-81 and five were men aged 22-58. In nine cases, positive reactions to one or more textile dyes were observed. Dark dyes, primarily various kinds of disperse blue, were involved. Three of the patients tested positively to textile finishes. Of 18 patients additionally tested with acetone-soaked samples of their clothing or shoes, five reacted positively. Allergic reactions to textiles in general are rare but should not be overlooked when diagnosing the causes of contact dermatitis.
Dermatosen in Beruf und Umwelt, Mar.-Apr. 1995, Vol. 43, No.2, p.63-68. Illus. 26 ref.
Thermal comfort of throw-away protective clothing
Thermophysiologischer Tragekomfort von Einwegschutzkleidung [in German]
Forty fabrics used for protective clothing were tested for permeability to water vapour, water vapour uptake, water uptake, heat storage and heat insulation. The fabrics were made of coated or uncoated polyethylene or polypropylene. Measurements were made of the heart rate, skin temperature and sweat rate of volunteers wearing 17 different kinds of throw-away overalls made of synthetic fabrics and two different kinds of cotton fabrics. The climatic conditions and workloads were determined in a questionnaire survey. Activities such as asbestos removal, waste site cleanup, varnishing of vehicles and pesticide application were included in the survey. The thermal comfort of throw-away protective overalls made of synthetic fibres was found to be much lower than that of cotton clothing. Longer periods of wear may lead to excessive increases of body temperature and heart rate.
Die BG, Apr. 1995, No.4, p.178-182. Illus. 5 ref.
Gebhardt H., Müller B.H., Hettinger T., Pause B.
Bundesanstalt für Arbeitsschutz
Physiological evaluation of work areas heated by radiators
Physiologische Bewertung von Strahlungsheizungen [in German]
Radiators are used for heating in various workplaces, such as factories, construction sites etc. In order to derive a uniform system for the physiological evaluation of work areas where radiators are used for heating, a method was developed in a series of laboratory tests to measure the combined effect of heat transmission by convection and radiation in the case of asymmetric radiation. These tests were conducted at air temperatures between -5°C et +15°C, under varying conditions of work task, heat intensity and heat distribution. Objective and subjective physiological effects were included in the evaluation. Based on tolerated conditions, the maximum recommended radiation intensity asymmetry depended largely on the actual air temperature. Considering the perceived temperature levels, good correlation was found between the physiological effects and the black bulb and operating temperatures in the room (ISO 7730, DIN 1946, part 2). On the other hand, no evidence was found for justifying the present-day size requirements for gas-burning radiators, as the thermal radiation they generate seems to have been significantly overestimated. Summaries in German, English and French.
Wirtschaftsverlag NW, Verlag für neue Wissenschaft GmbH, Postfach 10 11 10, 27511 Bremerhaven, Germany, 1995. vi, 107p. Illus. 27 ref.
Carretero R.M., Gómez-Cano M., Lezcano V.M.
Standards for the evaluation of thermal environments in the workplace
Normativa para la evaluación de los ambientes térmicos de trabajo [in Spanish]
Summary of the various legislative instruments and standards that apply to the evaluation of thermal work environments in Spain. The following information sources are summarized: Annexes I and II of Directive 89/654/EEC (CIS 90-356) on the minimum OSH requirements for the workplace; preparatory work on an EU directive concerning physical hazards in the workplace; ISO, CEN and AENOR (Spanish) standards. The provisions of existing standards on the measurement of thermal conditions are surveyed: measurement of basic temperature parameters; methods for the global evaluation of thermal environments (hot, moderate and cold); evaluation of physiological and psychological stress due to extreme temperatures. In annex: terminology of the preparation of standard; basic parameters used for the description of the thermal environment; scope of existing relevant standards.
Instituto Nacional de Seguridad e Higiene en el Trabajo, C/Torrelaguna 73, 28027 Madrid, Spain, 1995. 31p. 5 ref.
Lotens W.A., Pieters A.M.J.
Transfer of radiative heat through clothing ensembles
A mathematical model was designed to calculate the temperature and dry heat transfer in the various layers of a clothing ensemble, and the total heat loss of a person who is irradiated for a certain fraction of his or her area. The clothing ensemble that is irradiated by an external heat source is considered to be composed of underclothing, trapped air, and outer fabric. The model was experimentally tested with heat balance methods, using subjects, varying the activity, wind, and radiation characteristics of the outer garment of two-layer ensembles. In two experiments the subjects could only give off dry heat because they were wrapped in plastic film. The model appeared to be correct within about 1°C and 10Wm-2. In a third experiment, sweat evaporation was also taken into account, showing that the resulting physiological heat load of 10 to 30% of the intercepted additional radiation is compensation by additional sweating. The resulting heat strain was fairly mild. The mathematical model is a valid tool for the investigation of heat transfer through two-layer ensembles in radiant environments.
Ergonomics, June 1995, Vol.38, No.6, p.1132-1155. Illus. 24 ref.
Lotens W.A., Van de Linde F.J.G., Havenith G.
Effects of condensation in clothing on heat transfer
The condensation theory presented here enables calculation of the rate of vapour transfer with its associated effects on temperature and total heat transfer inside a clothing ensemble consisting of underclothing, enclosed air, and outer garment. The model was tested in three experiments: (1) impermeable garments worn by subjects with and without plastic wrap around the skin, blocking sweat evaporation underneath the clothing; (2) comparison of heat loss in impermeable and semi-permeable garments and the associated discomfort and strain; (3) subjects working in impermeable garments in cool and warm environments at two work rates, until the limit of tolerance was reached. The measured heat exchange and temperatures are predicted with satisfying accuracy by the model. Numerical analysis shows that the major determinants of heat loss are vapour permeability of the outer garment, skin vapour concentration and air temperature. In the cold, the condensation mechanism may completely compensate for the lack of permeability of the clothing as far as heat dissipation is concerned, but in the heat, impermeable clothing is more stressful.
Ergonomics, June 1995, Vol.38, No.6, p.1114-1131. Illus. 18 ref.
Lotens W.A., Havenith G.
Effects of moisture absorption in clothing on the human heat balance
A theory of moisture absorption in clothing, with the associated effects of heat transfer, was developed and applied in a computer model. The model considers the body, underclothing, an other layer, and the adjacent air layer. The theory was checked with an experiment involving four subjects who wore heavy woolen clothing, which was either initially dry or humid, in both a warm and a cool environment. Model calculations and experimental results agreed approximately upon the timing and magnitude of the effect of absorbent clothing on heat flows, temperatures and physiological reactions. Contrary to expectations, the vapour resistance observed was lower in the heat than in the cold, probably due to differences in sweat distribution. The usual way to determine clothing characteristics by partitional calorimetry leads to considerable errors when the steady state has not been reached. In clothing that has high absorption properties, the transient effects may be sustained for hours. Tests using the model show few beneficial effects of absorbent clothing on thermal sensation.
Ergonomics, June 1995, Vol.38, No.6, p.1092-1113. Illus. 27 ref.
Marszałek A., Sołtyński K., Sawicka A.
Physiological method of evaluating protective clothing for work in a cold environment
Three kinds of cold protective clothing were tested on six male subjects performing ergometric exercises in a climatic chamber at -10 and -15°C. Changes in core and skin temperature, pulmonary minute ventilation, heart rate, body mass, and temperature and relative humidity under the clothes were measured. Results show that thermal equilibrium was achieved and maintained throughout the investigated work time (60min) and that the tested clothing may be worn during the whole shift. Changes in thermal stress criteria can be used to determine the maximum duration of exposure for cold protective clothing with unknown thermal insulation.
International Journal of Occupational Safety and Ergonomics, 1995, Vol.1, No.3, p.235-243. Illus. 12 ref.
Chad K.E., Brown J.M.M.
Climatic stress in the workplace - Its effect on thermoregulatory responses and muscle fatigue in female workers
Thermoregulatory responses and levels of muscle fatigue were investigated in a group of seated women performing a light manual task (typing) and a group of standing women performing a more strenuous manual task (lifting) in different climatic conditions (neutral and hot, humid). Environmental heat significantly influenced the cardiovascular and regulatory systems in both groups. Although the lifters generally showed greater levels of thermal stress and muscle fatigue, the typists showed greater evidence of temperature-related muscle fatigue. Results suggest that the effects of environmental heat may be of secondary importance to the nature of the task on the levels of muscle fatigue experienced.
Applied Ergonomics, Feb. 1995, Vol.26, No.1, p.29-34. 12 ref.
Heus R., Daanen H.A.M., Havenith G.
Physiological criteria for functioning of hands in the cold
In this literature review, the physiological processes in manual dexterity are described and the influence of a cold environment on these processes is studied. Implications for manual dexterity are discussed. Factors influencing dexterity are reaction time, sensibility, nerve conduction, grip strength, time to exhaustion and mobility. Minimum criteria are given for separate physiological components of dexterity. The most important are a local skin temperature of 15°C, a nerve temperature of 20°C, and a muscle temperature of 28°C. During maximum dynamic work a muscle temperature of 38°C is recommended.
Applied Ergonomics, Feb. 1995, Vol.26, No.1, p.5-13. 57 ref.
Ceron R.J., Radwin R.G., Henderson C.J.
Hand skin temperature variations for work in moderately cold environments and the effectiveness of periodic warming
Hand skin temperature variations were studied among 15 workers performing jobs under different thermal conditions in a turkey processing plant. Averaged over all jobs, the mean temperature of the third finger (17.7°C) was significantly cooler than that of the hand (28.9°C). In the cold environment, hand temperatures were recorded both with and without periodic warming of the hands under hot running water. Warming the hands did not appreciably raise minimum finger skin temperature after subjects rewarmed the hands for as long as 2min and then worked for more than 10min without a rewarming session.
American Industrial Hygiene Association Journal, June 1995, Vol.56, No.6, p.558-567. Illus. 40 ref.
Cold weather worker's safety guide
Safety guide useful for the training of workers for outdoor work in cold weather. Contents: elements of on-the-job safety; safety inspections, accident investigation and reporting, first aid; cold weather safety - hazards due to cold, measurement of cold (including wind chill factors), dressing warmly, maintenance of cold-weather clothing, working safely on snow and ice, ice safety on frozen bodies of water, vital signs of cold injury (including prevention and treatment of frostbite, hypothermia, trench foot, white finger and carpal tunnel syndrome); cold-weather work in remote areas; general safety in outdoor work (electric safety, ladders, chain saws, compact loaders, snow throwers, shovelling and digging, manual material handling, truck start up, infectious waste); safety guidelines for the work environment; personal protective equipment; OSH legislation in Canada.
Canadian Centre for Occupational Health and Safety (CCOHS), 250 Main Street East, Hamilton, Ont. L8N 1H6, Canada, 1995. 104p. Illus. Price: CAD 10.00 (+ GST) in Canada; USD 10.00 (elsewhere).
The respiratory system in a cold environment
This literature survey focuses on how acute or chronic exposure to a cold environment affects respiratory system functions either through direct, reflex or mediator release mechanisms. The first section describes the basic physiological effects of cold exposure on pulmonary mechanics, control of breathing, pulmonary circulation and morphology of the respiratory system. Remaining sections describe clinical disorders that may be precipitated by acute or chronic cold exposure: exercise- or cold-induced asthma; rhinitis; cough and nose bleed; frozen lung; upper airway tract infections; Eskimo lung; tuberculosis.
Aviation, Space, and Environmental Medicine, Sep. 1995, Vol.66, No.9, Section I, p.890-902. Illus. 163 ref.
Ha M., Tokura H., Yamashita Y.
Effects of two kinds of clothing made from hydrophobic and hydrophilic fabrics on local sweating rates at an ambient temperature of 37°C
A comparison was made of the local sweat rates from the forearm in six subjects wearing either polyester or cotton clothing at an ambient temperature of 37°C. Local sweat rates were distinctly higher for polyester clothing than for cotton clothing in five out of six subjects. Clothing surface temperatures at the chest level were higher for cotton than for polyester. The different properties of moisture absorbency between the two materials could play a role in sweating physiology in environmental conditions where only wet heat loss could occur.
Ergonomics, July 1995, Vol.38, No.7, p.1445-1455. 19 ref.
Gun R.T., Budd G.M.
Effects of thermal, personal and behavioural factors on the physiological strain, thermal comfort and productivity of Australian shearers in hot weather
A study was made of 35 sheep shearers and 8 wool-press operators undertaking sustained strenuous work in air temperatures up to 45°C. Many of the findings were negative or paradoxical. The subjects experienced little of the increased strain that was expected on the basis of laboratory findings; fatter men and those who had drunk more alcohol the previous evening actually experienced less strain. The findings highlight the uncertainty inherent in defining safe limits for occupational heat stress on the basis of laboratory studies.
Ergonomics, July 1995, Vol.38, No.7, p.1368-1384. Illus. 39 ref.
Bundesanstalt für Arbeitsschutz
Work in moderately cold environments
Arbeit in mässiger Kälte [in German]
According to estimates, more than 200,000 workers work in cold environments in Germany. A questionnaire survey (1213 respondents) was conducted in the former Western Länder to study the repercussions of work in moderately cold environments (-5 to +15°C) (individual variables, occupational exposures, reactions to cold temperatures and physiological disorders) often associated with the handling of heavy loads and piece work. A significant association was found between health disorders (psychovegetative and gastro-intestinal symptoms, bronchitis, rheumatisms, musculoskeletal disorders and Raynaud's syndrome) and work in moderately cold environments.
Wirtschaftsverlag NW, Postfach 10 11 10, Am Alten Hafen 113-115, 2850 Bremerhaven 1, Germany, 1995. 185p. Illus. Approx. 160 ref.
Work in cold environments
This document contains the text of the lectures presented during a course for safety and health professionals on the problems of cold working conditions, the assessment of health risks and the development of prevention strategies. Main topics covered: research; case studies; acclimatization to cold; heat exchange, thermal balance and temperature regulation; thermal modelling; cold-related diseases (cryopathies) and injuries; adverse effects of cooling on physical performance capacity; first aid education for outdoor workers; clothing requirements for protection against cold; evaluation of cold environments.
Arbetsmiljöinstitutet, Förlagstjänst, 171 84 Solna, Sweden, 1994. 118p. Illus. Bibl.ref.
Beshir M.Y., Kähkönen E., Makambaya S., Hanna G.B., Crockford J., Muchiri F.K., Dees G.C.D., Mgeni A.Y., Lehtinen S.
Thermal work environment
This issue is primarily devoted to the topic of thermal work environments. Contents: thermal work environments and ISO standards; work in cold environments; review of a heat stress study in Tanzania involving several sectors (manufacture of farm tools, production of corrugated steel sheets, foundry, glass works); thermal analysis of buildings in new urban settlements in Egypt; work-wear and protective clothing for use in hot workplaces in developing countries. Other topics: chemical safety in small-scale industries in Kenya; mortality of employees from 1989 to 1992 in a pulp and paper mill in Swaziland; role of WHO in promoting occupational health in Africa.
African Newsletter on Occupational Health and Safety, Apr. 1994, Vol.4, No.1, p.1-23 (whole issue). Illus. 24 ref.
Luna Mendaza P.
Heat stress assessment. Sweat rate
Evaluación del estrés térmico. Indice de sudoración requerida [in Spanish]
Topics: data sheet; heat load; heat stress assessment; heat stress indices; mathematical models; permissible levels; Spain; sweat rate; WBGT index.
Instituto Nacional de Seguridad e Higiene en el Trabajo, Ediciones y Publicaciones, c/ Torrelaguna 73, 28027 Madrid, Spain, 1994. 6p. Illus. 3 ref.
Moderate thermal environments - Determination of the PMV and PPD indices and specification of the conditions for thermal comfort
This international standard (update of ISO 7730, see CIS 85-1284) is one of a series of standards, specifying methods of measuring and evaluating moderate and extreme thermal environments to which man is exposed. It covers the evaluation of moderate thermal environments, presents a method for predicting the thermal sensation and the degree of discomfort (thermal dissatisfaction) of people exposed to moderate thermal environments and specifies acceptable thermal environmental conditions for comfort. Main contents: predicted mean vote (PMV); predicted percentage of dissatisfied (PPD); draught rating; acceptable thermal environments for comfort. Annexes: metabolic rates of different activities; computer program for calculating predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD); tables for determining predicted mean vote (PMV) at 50% relative humidity; recommended thermal comfort requirements; estimation of thermal insulation of clothing ensembles.
International Organization for Standardization, Case Postale 56, 1211 Genève 20, Switzerland, 2nd ed., 1994. iv, 27p. Bibl.ref. Price: CHF 71.00.
The influence of the microclimate in commercial vehicles on the driver's performance
Der Einfluss des Mikroklimas im Nutzfahrzeug auf die Leistungsfähigkeit des Fahrers [in German]
The results of simulation tests are used to illustrate the effects of temperature rises in the driver's cab. An increase to 30°C increased the number of errors by 28%. At an increase to 35°C the errors rose by 40%. Present air conditioning systems for commercial vehicles are helpful in maintaining a comfortable climate that neither lowers the attention-span of drivers nor increases their reaction time.
ATZ, July-Aug. 1994, Vol.96, No.7-8, p.406-410. Illus. 7 ref.
Kampmann B., Piekarski C.
Calculation of the permissible length of exposure in workplaces with extreme climatic conditions according to the standard ISO 7933
Berechnung von zulässigen Expositionszeiten für klimabelastete Arbeitsplätze durch die Norm ISO 7933 [in German]
The length of exposure to heat in anthracite mining is calculated according to the standard ISO 7933 (see CIS 90-1357) in function of various types of clothing and various air velocities. In addition, the workloads which would allow 300, 360 and 480 minutes of work in the moist and hot climate of anthracite mining are calculated according to the standard. Results are presented in the form of graphs identifying those workplaces where environmental conditions lead to intolerable increases in body temperature. A comparison of predictions with measurements reveals the shortcomings of the standard. It is recommended that the mathematical model on which the standard is based be improved with the help of new data from field measurements.
Institut für Arbeitswissenschaften der Ruhrkohle AG, Wengeplatz 1, 44369 Dortmund, Germany, 1994. 65p. Illus. 14 ref.
Cold stress: Part I - Guidelines for the practitioner; Part II - The scientific basis (knowledge base) for the guide
In the first part, a guideline is presented intended for persons involved in the design, planning and control of operations intended for cold environments as well as in the actual organization and performance of such work. The guideline provides recommendations on suitable and relevant methods for assessment and control of different types of cold stress as well as examples of measures for their alleviation and prevention. In the second part, the scientific basis of the guide is presented. Topics include: a description of the scope of the problem of cold stress; the health effects of cold; the quantification of cold stress; measures for the prevention and alleviation of cold stress; suggestions for further research.
International Journal of Industrial Ergonomics, Aug. 1994, Vol.14, Nos.1-2, p.139-159. 92 ref.
O'Leary C., Parsons K.C.
The role of the IREQ index in the design of working practices for cold environments
For any cold environment a calculation can be made of the minimum clothing insulation required by workers (IREQ). Two studies are reported which investigated the role of the IREQ index in the design of working practices for cold indoor environments. The two studies suggest that the use of the IREQ index alone as a working practice may not be adequate to provide thermal comfort. The IREQ index was suggested as adequate initial protection against the strain induced on a worker in a cold environment. The design tool included the IREQ index as an initial indicator of cold stress; subsequent application of local clothing adjustment, followed by suitable general working practices were then required to achieve thermal comfort.
Annals of Occupational Hygiene, Oct. 1994, Vol.38, No.5, p.705-719. Illus. 10 ref.
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