Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia.
Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia.
Am J Ind Med. 2019 Dec;62(12):1058-1067. doi: 10.1002/ajim.23035. Epub 2019 Aug 16.
Laboring in hot and humid conditions is a risk factor for heat-related illnesses. Little is known about the amount of physical activity performed in the field setting by agricultural workers, a population that is among those at highest risk for heat-related mortality in the United States.
We measured accelerometer-based physical activity and work activities performed in 244 Florida agricultural workers, 18 to 54 years of age, employed in the fernery, nursery, and crop operations during the summer work seasons of 2015-2017. Environmental temperature data during the participant's workdays were collected from the Florida Automated Weather Network and used to calculate wet bulb globe temperature (WBGT). Generalized linear mixed model regression was used to examine the association between WBGT on physical activity, stratified by the agricultural sector.
Fernery workers had the highest overall volume of physical activity, spending nearly 4 hours in moderate to vigorous activity per workday. Activity over the course of the workday also differed by the agricultural sector. A reduction on average physical activity with increasing environmental temperature was observed only among crop workers.
The quantity and patterns of physical activity varied by the agricultural sector, sex, and age, indicating that interventions that aim to reduce heat-related morbidity and mortality should be tailored to specific subpopulations. Some workers did not reduce overall physical activity under dangerously hot environmental conditions, which has implications for policies protecting worker health. Future research is needed to determine how physical activity and climatic conditions impact the development of heat-related disorders in this population.
在炎热和潮湿的环境中劳动是导致与热相关疾病的一个风险因素。对于在田间劳作的农业工人，他们的体力活动量知之甚少，而这一人群是美国与热相关死亡率最高的人群之一。
我们测量了 244 名 18 至 54 岁的佛罗里达州农业工人在 2015 年至 2017 年夏季工作季节期间在蕨类植物、苗圃和作物种植中从事农业工作时的基于加速度计的体力活动和工作活动。从佛罗里达州自动气象网络收集参与者工作日的环境温度数据，并用于计算湿球黑球温度（WBGT）。使用广义线性混合模型回归分析 WBGT 与体力活动之间的关联，并按农业部门进行分层。
蕨类植物工人的总体体力活动量最高，平均每天有近 4 个小时的中等到剧烈活动。整个工作日的活动也因农业部门而异。只有在作物工人中观察到随着环境温度的升高，平均体力活动量减少。
体力活动的数量和模式因农业部门、性别和年龄而异，这表明旨在降低与热相关发病率和死亡率的干预措施应针对特定的亚人群。一些工人在危险的炎热环境条件下并没有减少总体体力活动，这对保护工人健康的政策提出了挑战。未来需要研究体力活动和气候条件如何影响该人群中与热相关疾病的发展。
