ABSTRACT

Forest workers encounter many health-related problems due to their harsh working conditions. This study focused on the evaluation of the physical workload of tree fellers during clearcut operations in a pine plantation forest in northern Iran by means of heart rate measurements. Anthropometric and personal data of the subjects such as age, body mass index (BMI), work experience, and health problems were also collected. The subjects were also asked to assess their perceived level of fatigue by means of the Swedish Occupational Fatigue Inventory. Activity sampling was used to record the physical workload of 13 subjects during a working day of 8 h for each one of them by means of a Polar Electro H10 heart rate sensor. The collected data were used for the calculation of heart rate indices that determine the strain of the subjects. The results showed that the mean level of physical workload was 43.54% of the relative heart rate (HRR) which corresponds to heavy work. The workers assigned most of the effective work time to tree processing (39.78%), back cut (18.6%), and undercut (12.07%). The highest mean heart rates (HR_work) were measured during the work elements of tree processing (117.7 bpm), back cut (115.6 bpm), and undercut (114.8 bpm). The study results also showed that the number of harvested trees and the average tree diameter at breast height exerted a significant impact on HRR and the BMI class on HR_work. Furthermore, age class was negatively correlated to net productivity.

摘要

由于工作条件恶劣，林业工人会遇到许多与健康有关的问题。这项研究的重点是通过心率测量来评估在伊朗北部松树人工林中伐木作业期间伐木者的体力工作量。还收集了受试者的人体测量学和个人数据，例如年龄、体重指数 (BMI)、工作经验和健康问题。还要求受试者通过瑞典职业疲劳量表来评估他们感知的疲劳程度。活动采样用于通过 Polar Electro H10 心率传感器记录 13 名受试者在 8 小时工作日内为每名受试者记录的体力工作量。收集的数据用于计算确定受试者应变的心率指数。结果表明，体力工作的平均水平是相对心率 (HRR) 的 43.54%，对应于繁重的工作。工人将大部分有效工作时间分配给树木加工 (39.78%)、回切 (18.6%) 和底切 (12.07%)。最高平均心率（HR_work ) 是在树木处理 (117.7 bpm)、回切 (115.6 bpm) 和底切 (114.8 bpm) 的工作元素期间测量的。研究结果还表明，采伐的树木数量和平均胸高树木直径对HRR和BMI等级对HR_工作产生显着影响。此外，年龄等级与净生产力呈负相关。