Original scientific paper
Theoretical and practical weaknesses of Yugoslav standards of the thermal environment
F. Valić
; Škola narodnog zdravlja »Andrija Štampar« Medicinskog fakulteta Sveučilišta u Zagrebu, Zagreb, Hrvatska
M. Cigula
; Škola narodnog zdravlja »Andrija Štampar« Medicinskog fakulteta Sveučilišta u Zagrebu, Zagreb, Hrvatska
Abstract
Theoretical weaknesses and practical difficulties in the application of Yugoslav thermal standards are demonstrated by field examples. The standards are expressed as threshold values separately for temperature, humidity, air velocity and radiant temperature, disregarding the fact that the physiological response of man to thermal stress is an integrated function of these factors. The application of the results of the field measurements of thermal factors at 106 work sites in seven different industries demonstrates unnecessary overburdening of industry with too strict demands. Nonphysiological is also the approach of the rules on safety at work requesting that the limiting values of the work environment factors be applied to the work place without consideration given to the worker's time spent at that place during work shift. Introduction of physiologically justified »thermal indices« and use of »weighted« values for the assessment of heat stress during shift in the standards is recommended. The results of measurements at all 106 work sites demonstrate high intercorrelations between the values of the effective temperature (ET), the corrected effective temperature (CET) and the wet bulb-globe temperature (WBGT) (r>0.9; P<0.01). However, the presented regression equations describing the relationship between WBGT versus CET and ET, respectively, at different conditions of air temperature, humidity and radiant temperature, show that WBGT-CET relationships remain very similar within a broad range of different thermal conditions, whilst WBGT-ET relationship is significantly altered both at high radiant temperature and low humidity. This suggests that both WBGT and CET may be equally satisfactory. For this reason the introduction of the simplest among thermal indices »the wet bulb-globe temperature« is recommended. Additional advantage of the index recommended is that it can be »weighted«.
Keywords
Hrčak ID:
152750
URI
Publication date:
25.4.1989.
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