Effects evaluation of Heat Stress Index and workload to miner’s fatigue level in underground gold mining area PT Dwinad Nusa Sejahtera

Mining is an activity with a high risk of accidents in open pit and underground mining sites. Various factors that cause accidents have been found through accident investigation, such as miners’ fatigue. Miner’s fatigue can be caused by environmental factors and workload that can be controlled to make a safe and comfortable working environment and prevent accidents. This research objective is to evaluate the relationship between environment factors in the form of heat stress index using humidex method and workload to miner’s fatigue level in the underground mining area PT. Dwinad Nusa Sejahtera. This research was done by measuring the working environment to know humidex, workload and miners fatigue level. Working environment conditions in the underground gold mine of PT. Dwinad Nusa Sejahtera is in a hot and humid condition with wet temperature range are 28.5–32.9°C, dry temperature range are 29.7–33.0°C, globe temperature range are 29.7–33.5°C wet bulb globe temperature range are 29.0–32.1°C, relative humidity range are 83.1–100% and humidex are 49.5–59.5°C. Multivariate analysis of miner’s fatigue level in all activity groups shows that the humidex variable gives more significant effects than the workload variable.