Experimental Research on Health and Safety Measures for Working in Hot Weather

Abstract

Heat stress, having caused preventable and lamentable deaths, is hazardous to construction workers in the hot and humid summers of Hong Kong. The Construction Industry Council (CIC) addressed this important issue by setting up an Informal Task Force on Working in Hot Weather. The CIC has recently promulgated a set of basic guidelines on site safety measures in hot weather. The Informal Task Force, however, advocates in the 5th Progress Report of Committee on Construction Site Safety to the CIC that further research on thermal stress measured by established parameters should be conducted to refine the initial guidelines. A leading contractor in Hong Kong has also advocated the need to undertake trade specific investigation for working in hot weather.  

The aim of this study is to address this pressing need of the industry by deriving scientific indices to assess the effects of heat stress on construction workers working in hot weather. The objectives are to make use of Clinical Experimental Design (CED) and Remote Sensing (RS) technology such as Global Positioning System (GPS) to establish indices to detect impending attacks of heat stress and recommend pertinent safety measures for construction workers.  Heat stress evaluation can generally be done through meteorological parameters and physiological parameters. A set of physiological and environmental parameters, namely oral temperature, skin temperature, ambient temperature, relative humidity, heart rate variability, blood pressure and sweating responses will be measured and monitored to find out physiological limit values at different heat exposures.  Since bar benders and fixers usually have to work in open areas without shading when fixing reinforcement bars, arguably one of the most physically demanding trades, the bar bending and fixing trade is selected as the prototype for developing a more focused methodology which if successful could also be applied to other trades.  The choice is in line with Balasubramanian and Prasad’s study (2007) which recognised bar bending and fixing as one of the most hazardous trades in the construction industry.

This study will derive a set of indices measurable by clinical and scientific methods enabling detection of impending attacks of heat stress offering the prospect of increased safety, particularly, at this stage, for bar benders and fixers.