School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
Scand J Work Environ Health. 2023 Jan 1;49(1):43-52. doi: 10.5271/sjweh.4057. Epub 2022 Oct 9.
The aim of this study was to quantify the physiological workload of manual laborers in industrial sugarcane and assess the effect of receiving a rest, shade, and hydration intervention to reduce heat stress exposure risk.
In an observational study, physiological workload was evaluated for burned cane cutters (BCC), seed cutters (SC) and drip irrigation repair workers (DIRW) using heart rate (HR) recorded continuously (Polar®) across a work shift. Workers' percentage of maximal HR (%HR), time spent in different HR zones, and estimated core temperature (ECTemp) were calculated. The effect of increasing rest across two harvests was evaluated for BCC and SC.
A total of 162 workers participated in this study [52 BCC (all male), 71 SC (13 female) and 39 DIRW (16 female)]. Average %HRmax across a work shift was similar between BCC and SC (BCC: 58%, SC: 59%), but lower in DIRW (51%). BCC and SC spent similar proportions of work shifts at hard/very hard intensities (BCC: 13%, SC: 15%), versus DIRW who worked mostly at light (46%) or light-moderate (39%) intensities. SC maximum ECTemp reached 38.2°C, BCC 38.1°C; while DIRW only reached 37.7°C. Females performed at a higher %HR than males across work shifts (SC 64% versus 58%; DIRW 55% versus 49%). An additional rest period was associated with a lower average %HR across a work shift in BCC.
In this setting, BCC and SC both undertake very physiologically demanding work. Females maintained a higher workload than male co-workers. Regulated rest periods each hour, with water and shade access, appears to reduce physiological workload/strain.
本研究旨在量化工业甘蔗种植中体力劳动者的生理工作量，并评估接受休息、遮荫和补水干预措施以降低热应激暴露风险的效果。
在一项观察性研究中，使用连续记录的心率（Polar®）评估砍收甘蔗工人（BCC）、种苗切割工人（SC）和滴灌修复工人（DIRW）的生理工作量。计算工人的最大心率百分比（%HR）、不同心率区间的时间和估计核心体温（ECTemp）。评估在两个收获季增加休息时间对 BCC 和 SC 的影响。
共有 162 名工人参与了这项研究[52 名 BCC（均为男性）、71 名 SC（13 名女性）和 39 名 DIRW（16 名女性）]。BCC 和 SC 在整个工作班次的平均%HRmax 相似（BCC：58%，SC：59%），但 DIRW 较低（51%）。BCC 和 SC 有相似比例的工作时间处于高强度/非常高强度（BCC：13%，SC：15%），而 DIRW 主要在轻强度（46%）或轻-中强度（39%）下工作。SC 的最大 ECTemp 达到 38.2°C，BCC 为 38.1°C；而 DIRW 仅达到 37.7°C。女性在整个工作班次中的心率均高于男性（SC 为 64%，BCC 为 58%；DIRW 为 55%，BCC 为 49%）。在 BCC 中，额外的休息时间与整个工作班次中的平均%HR 较低有关。
在这种情况下，BCC 和 SC 都承担着非常生理需求高的工作。女性的工作量高于男性同事。每小时安排规定的休息时间，提供水和遮荫，似乎可以降低生理工作量/压力。
