Description
Background:
Fly-in/fly-out night-shift mining operators experience cumulative fatigue and drowsiness that impair alertness and safety. This field study evaluated blue stimulating light as a mitigation strategy during extended night-shift rotations. Blue light activates brain alertness pathways via melanopsin-sensitive retinal cells. The technology is based on a CERVO Brain Research Center discovery showing that pulsed blue light at 70 Hz doubles biological efficacy compared with continuous blue light (US Patent 11,259,738), enabling low-intensity use in dim work environments. Alertness was assessed using the Psychomotor Vigilance Test (PVT), a widely validated measure of vigilance.
Methods:
Thirteen fly-in/fly-out rotating shift workers performing computer and screen-monitoring tasks at the Raglan Mine (Glencore), Northern Québec (61°69’N), completed twelve consecutive 12-hour night shifts (7 PM–7 AM) under two counterbalanced conditions: with and without blue light mounted above the computer screen. PVT testing was conducted at the beginning and end of each shift. Mean daily median reaction times were analyzed.
Results:
Without blue light, reaction time increased by 3.5 ms per successive shift from day 1 to day 12 (p < 0.01), indicating cumulative performance decline. With blue light, the increase was limited to 1.1 ms, with improved reaction times observed by the end of the twelfth shift (p < 0.05), effectively mitigating fatigue-related performance loss. Following this study, a portable in-cabin blue-light system was deployed in an open-pit mine; 85% of 61 haul-truck operators (Caterpillar F793) reported improved alertness and 94% reported better sleep.
Conclusion:
Pulsed blue light at 70 Hz represents an innovative, low-intensity stimulation paradigm associated with improved alertness and reduced fatigue accumulation across consecutive night shifts. This approach may be considered for integration into mining fatigue risk management programs.