Mining Publication: Mine Worker Fatigue and Circadian Rhythms

The mining industry often uses shift work schedules with the intention to have a productive working mine around the clock. However, one potential side effect of operating on a 24/7 basis can be the disruption of circadian rhythms, which results in worker fatigue — the mental state between wake and sleep. Fatigue from shift work has the potential to decrease productivity and increase accidents in organizations where workers are overly fatigued (Dawson et al., 2000). In open pit mines fatigue-related accidents account for up to 65% of truck driving accidents alone (Schmidt, 2015).

The detrimental effects of severe fatigue include more than loss of productivity and accidents. Several potential health effects are directly associated with fatigue, including trouble sleeping, decreased alertness, slower reaction time, and a weakened immune system. Workers suffering from fatigue also show a general decline in cognitive abilities, such as problem solving and working memory. More serious health consequences of long-term chronic fatigue may include diabetes, obesity, heart disease, and an increased risk of cancer (Kecklund and Axelsson, 2016).

Although one cause of fatigue is lack of adequate sleep, fatigue is not the same as sleepiness. Additionally, fatigue can result from the disruption of circadian rhythms, also known as the body’s “biological clock.” Circadian rhythms are highly affected by the natural cycle of daylight, and varying exposure to light causes a disruption. Hence, shift workers are inherently at risk of circadian disruption, with their working hours extending into the night or early morning. This disruption can cause us to have problems with getting enough sleep. Even one night of poor sleep — defined as either less than seven consecutive hours or frequent waking — can have negative effects on our health (Watson et al., 2015).