Hydration status and physiological workload of UAE construction workers: a prospective longitudinal observational study

Abstract

BackgroundThe objective of the study was to investigate the physiological responses of construction workers labouring in thermally stressful environments in the UAE using Thermal Work Limit (TWL) as a method of environmental risk assessment.MethodsThe study was undertaken in May 2006. Aural temperature, fluid intake, and urine specific gravity were recorded and continuous heart rate monitoring was used to assess fatigue. Subjects were monitored over 3 consecutive shifts. TWL and WBGT were used to assess the thermal stress.ResultsMost subjects commenced work euhydrated and maintained this status over a 12-hour shift. The average fluid intake was 5.44 L. There were no changes in core temperature or average heart rate between day 1 and day 3, nor between shift start and finish, despite substantial changes in thermal stress. The results obtained indicated that the workers were not physiologically challenged despite fluctuating harsh environmental conditions. Core body temperatures were not elevated suggesting satisfactory thermoregulation.ConclusionThe data demonstrate that people can work, without adverse physiological effects, in hot conditions if they are provided with the appropriate fluids and are allowed to self-pace. The findings suggested that workers will self-pace according to the conditions. The data also demonstrated that the use of WBGT (a widely used risk assessment tool) as a thermal index is inappropriate for use in Gulf conditions, however TWL was found to be a valuable tool in assessing thermal stress.

Comparing the physiological and perceptual responses of construction workers (bar benders and bar fixers) in a hot environment

“…It has been reported and observed that construction workers will self-pace, adjusting either the work rate or the duration of work intervals to maintain thermal balance and avoid heat related illness (Bates and Schneider, 2008;Taylor, 2006). In this regard, it has been shown that there was no difference in manual workers' heart rate responses under variate environmental heat stress and it is evident that self-pacing is a protective response to working in heat which does not require a highly informed workforce …”

“…Therefore, it is important to deliver an active education program and promoting awareness of sufficient hydration and rehydration strategy to rebar workers. It has been shown that construction workers who begin work in well hydrated conditions are likely to maintain good levels of hydration during the shift (Bates and Schneider, 2008). Additionally, it is also useful to screen the hydration status of rebar workers at the worksite such as before work, during breaks, and after work.…”

“…189.3 to 237.7 W/m 2 ) (Bates and Schneider, 2008). Under a full solar load, the body experiences radiative heat gains from the sun and the nearby hot surfaces.…”

Assessment of construction workers’ hydration status using urine specific gravity

“…Brake and Bates considered USG equal to 1.015 as a euhydrated state [7]. Thermal Work Limit (TWL), a newly developed index, incorporates all needed inputs and generates a single figure specifying a maximum work limit and is claimed to be "simple to use, less prone to interpretive error, reliable and far superior to currently recommended indices an indicator of thermal stress" [3]. All 5 main parameters that define thermal environment, i.e.…”

New methodology for the walls design in buildings by numerical simulation of the thermal convection

“…air temperature, radiant temperature, humidity, air movement, metabolic rate or human activity [35,36]. Also, numerous studies across the world have shown the impacts of hot working environments on the working population [37][38][39][40][41][42][43]. The choice of which material or combination of materials is used depends on a wide variety of factors.…”