Can Heart Rate Variability (HRV) Be Used as a Biomarker of Thermal Comfort for Mine Workers?

Guoshan Wu,Shixian Wu,Caihang Liang,Guanglei Liu,Heqing Liu

doi:10.3390/ijerph18147615

Abstract

This study aimed to determine whether heart rate variability (HRV) can express the thermal comfort of mine workers. Eight subjects ran on a treadmill (5.5 km/h) to simulate heavy labor in three kinds of mining environments (22 °C/90%, 26 °C/90%, 30 °C/90%), respectively. Based on the measured electrocardiogram (ECG) data, the HRV of the subjects was calculated. The results showed that the HRV indices changed obviously under different temperature environments. In the neutral and hot environment, except for the LF, TP and LF/HF, there were significant differences in each index. However, there was no significant difference between the cold and neutral environments. The R-R intervals, the very low-frequency power (VLF), pNN20 and SampEN had strong negative correlation with the thermal sensation of people from sitting to work (ρ < −0.700). These indices may be used as thermal comfort predictive biomarkers of mine workers.

Highlights

Coal is an important energy source for various countries [1]
The ECG and subjective thermal sensation votes of the subjects were obtained in this experiment
In the three kinds of thermal environments, the subjective thermal sensation votes of the subjects were between −1.88 and 2.38, as shown in Figures 2 and 3

Summary

Introduction

Coal is an important energy source for various countries [1]. With the reduction in shallow resources and the continuous demand for minerals, mines have become much deeper, and the temperature and humidity of mining workfaces have become much higher [2,3,4]. The combined effect of high temperature and high humidity may put workers’ health at risk [6,7]. People mainly used the combination of single or multiple climate parameters, such as ambient temperature and black ball temperature, to evaluate the thermal comfort of the underground environment. In many countries, such as the United States, the United Kingdom and Germany, the effective temperature (ET) has been used to evaluate the underground environment, and the labor management system has been formulated based on it [10]. WBGT was reliable and easy to use, and it can predict thermal comfort zone more accurately than the DI index [3]

Objectives

Methods

Results

Discussion

Conclusion