Validation of the Predicted Heat Strain Model in Hot Underground Mines

Abstract

Heat-Related Illnesses (HRI) are relatively common in both hot surface and underground mining operations. When workers are exposed to extreme heat or strenuous work in a hot environment they become prone to heat stress. Heat strain is the result of the body's response to external and internal heat stress. It is therefore vital for the conditions leading to heat strain be detected and treated in a timely manner. Heat-related illnesses are manifested by exhaustion and heat stroke. The Predicted Heat Strain (PHS) [ISO 7933 (2004)] model has been developed to predict the health condition of the worker in terms of core body temperature and water loss. The PHS Model tested in this study is based on eight physical parameters that are measured at different intervals during a work shift. They include air temperature, humidity, radiation, air velocity, metabolic rate, clothing insulation, posture and acclimatization. The model predictions are then compared with a direct physiological measurement, such as core body temperature. We present the results of an extensive study that monitored and predicted body's response to heat stress under different environmental and working conditions. The PHS model provided reliable results in most instances in comparison to other prediction methods currently in use in the field.

The Effects of the Dynamic Thermophysical Properties of Clothing and the Walking Speed Input Parameter on the Heat Strain of a Human Body Predicted by the PHS Model

“…Table 6 showed the predicted and observed values of the maximum exposure time of the three types of clothing. For NC-4, PHS with ISO 7933 or ISO 9920 corrections underestimated the maximum exposure time, which was similar to the previous studies [15]. However, when adding the v w input parameter and using the ISO 9920 corrections, the predicted time was closer to the experimental data.…”

Genetic programming for prediction of heat stress hazard in underground coal mine environment

“…Some of the important sources of heat include heat released from machinery, heat generated from blasting of explosives, geothermal gradient, auto-compression of air in down cast shaft, oxidation of coal and timber support, human metabolism, etc. (Lazaro and Momayez 2019). When the effective temperature (ET) of surrounding environment exceeds 30°C, the work e ciency of workers starts decreasing (Coco et al 2016).…”

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

“…In deep mining, workers are engaged in heavy physical labor, they are often in a state of thermal discomfort [ 5 ]. The combined effect of high temperature and high humidity may put workers’ health at risk [ 6 , 7 ]. Moreover their dissatisfaction with these working conditions is growing [ 7 , 8 , 9 ].…”

“…The combined effect of high temperature and high humidity may put workers’ health at risk [ 6 , 7 ]. Moreover their dissatisfaction with these working conditions is growing [ 7 , 8 , 9 ]. In addition, the body sweats a lot after heavy labor, and the clothes are often wet.…”

“…It has been widely recognized in the world. There was no significant difference between the predicted values of the PHS model and measured values of human core temperature in underground mines [ 7 ]. Many mining enterprises use it to conduct thermal stress assessment management [ 12 , 13 , 14 , 15 ] and study the movable refuge chambers of mining [ 14 ].…”