Miller Veronica S, Bates Graham P
School of Public Health, Curtin University of Technology, Western Australia.
Ann Occup Hyg. 2007 Aug;51(6):553-61. doi: 10.1093/annhyg/mem035.
Workers in many industries are exposed to thermally stressful work environments. Protection of the health of workers without unnecessarily compromising productivity requires the adoption of a heat index that is both reliable and easy to use.
To evaluate the Thermal Work Limit (TWL), in a controlled environment and under field conditions, against these criteria.
Volunteers performed graded work in a controlled thermal environment to determine the limiting workload for the conditions. Core temperature and heart rate were monitored as indicators of thermoregulation. In the field study, outdoor workers were monitored for signs of physiological strain in thermal environments which were characterized using both the traditional Wet Bulb Globe Temperature (WBGT) and the TWL. Abilities of each of these indices to accurately reflect the thermal stress on workers were evaluated.
In the controlled environment, the TWL was found to reliably predict the limiting workload. In the field study, TWL was a more appropriate and realistic index than WBGT, which was found to be excessively conservative.
The results confirm previously published studies evaluating TWL in underground environments, which have led to its widespread adoption in the Australian mining industry. The study extends the applicability of TWL to outdoor environments and generates management guidelines for its implementation.
许多行业的工人都面临热应激工作环境。在不过度影响生产力的前提下保护工人健康，需要采用一种既可靠又易于使用的热指数。
在可控环境和现场条件下，根据这些标准评估热工作极限（TWL）。
志愿者在可控热环境中进行分级工作，以确定这些条件下的极限工作量。监测核心体温和心率作为体温调节指标。在现场研究中，对户外工作者在热环境中的生理应激迹象进行监测，这些热环境使用传统的湿球黑球温度（WBGT）和TWL进行表征。评估这些指标中每一个准确反映工人热应激的能力。
在可控环境中，发现TWL能够可靠地预测极限工作量。在现场研究中，TWL比WBGT是更合适、更现实的指标，WBGT被发现过于保守。
结果证实了先前发表的在地下环境中评估TWL的研究，这些研究导致其在澳大利亚采矿业中广泛采用。该研究将TWL的适用性扩展到户外环境，并生成了其实施的管理指南。
