School of Health Sciences and Social Work, Griffith University, Gold Coast, Queensland, Australia.
Cities Research Institute, Griffith University, Gold Coast, Queensland, Australia.
Am J Ind Med. 2024 Jun;67(6):556-561. doi: 10.1002/ajim.23589. Epub 2024 May 2.
Occupational heat stress, exacerbated by factors such as climate change and insufficient cooling solutions, endangers the health and productivity of workers, especially in low-resource workplaces.
To evaluate the effectiveness of two cooling strategies in reducing physiological strain and productivity of piece-rate workers over a 9-h work shift in a southern Thailand sawmill.
In a crossover randomized control trial design, 12 (33 ± 7 y; 1.58 ± 0.05 m; 51 ± 9 kg; n = 5 females) medically screened sawmill workers were randomly allocated into three groups comprising an established phase change material vest (VEST), an on-site combination cooling oasis (OASIS) (i.e., hydration, cold towels, fans, water dousing), and no cooling (CON) across 3 consecutive workdays. Physiological strain was measured via core temperature telemetry and heart rate monitoring. Productivity was determined by counting the number of pallets of wood sorted, stacked, and stowed each day.
Relative to CON, OASIS lowered core temperature by 0.25°C [95% confidence interval = 0.24, 0.25] and heart rate by 7 bpm [6, 9] bpm, compared to 0.17°C [0.17, 0.18] and 10 [9,12] bpm reductions with VEST. It was inconclusive whether productivity was statistically lower in OASIS compared to CON (mean difference [MD] = 2.5 [-0.2, 5.2]), and was not statistically different between VEST and CON (MD = 1.4 [-1.3, 4.1]).
Both OASIS and VEST were effective in reducing physiological strain compared to no cooling. Their effect on productivity requires further investigation, as even small differences between interventions could lead to meaningful disparities in piece-rate worker earnings over time.
职业性热应激，加之气候变化和冷却解决方案不足等因素，危害工人健康和生产力，尤其是在资源匮乏的工作场所。
评估两种冷却策略在减少泰国南部一家锯木厂 9 小时工作班次中计件工人的生理应激和生产力的效果。
采用交叉随机对照试验设计，将 12 名（33±7 岁；1.58±0.05 米；51±9 千克；5 名女性）经医学筛查的锯木厂工人随机分为三组，分别为相变材料背心（VEST）、现场组合冷却绿洲（OASIS）（即水合作用、冷毛巾、风扇、水喷淋）和无冷却（CON），连续 3 天进行试验。通过核心体温遥测和心率监测来测量生理应激。通过每天计数分拣、堆叠和存放的托盘数量来确定生产力。
与 CON 相比，OASIS 降低了 0.25°C（95%置信区间 = 0.24，0.25）和 7 bpm（6，9）的核心体温和心率，而 VEST 分别降低了 0.17°C（0.17，0.18）和 10 bpm（9，12）。尚不能确定 OASIS 与 CON 相比，生产力是否存在统计学上的降低（平均差值[MD] = 2.5 [-0.2, 5.2]），且 VEST 与 CON 之间也无统计学差异（MD = 1.4 [-1.3, 4.1]）。
与不冷却相比，OASIS 和 VEST 都能有效降低生理应激。它们对生产力的影响需要进一步研究，因为即使干预措施之间存在微小差异，也可能导致计件工人的收入随着时间的推移出现显著差异。
