Are fatigue and sleepiness the same? A brief introduction to the differences and similarities, and their implications for work safety

While not well established, there is evidence that the mining industry is encumbered by several work-related fatigue risk factors. Compared to other industries, mine workers are more likely to report inadequate sleep and work longer hours per day. Given these observations, there is a critical need to identify effective ways to intervene, manage, and mitigate mine worker fatigue and sleepiness when present. One barrier to this is confusion around the similarities and differences between fatigue and sleepiness, which can result in these terms being treated as interchangeable regardless of context and make it difficult to assess and mitigate safety risk. Fatigue and sleepiness differences and similarities One way to define fatigue is as a state produced by a biological drive for recuperative rest, while sleepiness is defined as a sleep propensity or inclination to fall asleep. While defined differently, from a measurement perspective, neither sleepiness nor fatigue are directly measurable, and the observed effects of both look highly similar. As a result, indirect indicators are used, such as measuring a slower reaction time during a long shift. Distinguishing between fatigue and sleepiness requires examining the context in which the changes in these indicators occur. Thus, it is necessary to measure the risk factors that are co-occurring alongside these indicators and potentially leading to the observed changes. Fig. 1 The work safety visual model of fatigue and sleepiness. Fatigue and sleepiness have a variety of distinct and shared risk factors that provide context for determining which state is most likely the dominant condition. Factors that can be measured and are relatively sensitive to fatigue, as opposed to sleep, include time on task, task complexity and workload. These risk factors are unique to fatigue as they primarily fall under the criteria within the job demands- resources model and are exertion-based risk factors. For example, job demands such as monotonous or complex tasks can lead to increased fatigue risk if a job resource such as work breaks are not utilized to balance out demands on the worker. There are distinct factors that predict sleepiness. These factors include poor sleep quality, an inadequate amount of sleep, wakefulness during time periods of peak biological drive for sleep (usually between 2 a.m. and 6 a.m.), or sleep disorders. Some of the shared risk factors between sleepiness and fatigue include work schedules, long commutes and long working hours. These shared factors can have a draining effect on workers while also potentially disrupting optimal sleep schedules. This contextual information can provide additional insight into which condition better accounts for symptoms such as slowed reaction time. Although outcomes for fatigue and sleepiness are similar, interventions to address the two can be highly different. Treating fatigue and sleepiness as interchangeable can potentially result in misuse of interventions and the perception that the problem is being managed while it may persist unnoticed. It is therefore important to include considerations for both sleepiness and fatigue in a safety management system aimed at mitigating work-related fatigue risk for it to be more effective. As an example, if a worker is obtaining minimal sleep at night, focusing on job demands or task-based fatigue will likely have minimal impact. Likewise, after obtaining adequate sleep duration and quality, work factors such as extremely loud or hot work environments can still produce fatigue. Visually modeling fatigue versus sleepiness To depict the meaningful nuances between fatigue and sleepiness, and to aid workplace health and safety managers and workers alike, a visual model was developed. The following process was used to develop the model: (1) theoretical literature was reviewed to differentiate fatigue and sleepiness from each other, (2) specific literature on risk factors, measurement, and mitigation strategies for fatigue and sleepiness were reviewed and (3) an iterative approach to formulate a visual model representing the gathered information was taken until the current model, depicted in Fig. 1, was developed. The aim of this model is to provide a visual representation of the relationship between fatigue and sleepiness that identifies general differences and how fatigue and sleepiness might be mitigated differently at different points. The topleft box illustrates that risk factors for work-related fatigue primarily fall into the category of excess demands and limited resources, which leads to a state of overexertion, while the bottom-left box presents decreased opportunity for sleep as a primary risk factor for sleepiness, which leads to increased time spent awake and decreased time spent asleep. Some shared risk factors between sleepiness and fatigue include long working hours and long commutes. More targeted interventions can be implemented for prevention at this level, such as assessing the balance of job demands and resources in the work environment for fatigue and increasing opportunities for restful sleep through efficient shift-scheduling practices for sleepiness. If not prevented, these risk factors can lead to increased sleepiness or fatigue but could potentially be mitigated by work breaks or work rearrangements (for fatigue), planned naps or sleep disorder screening (for sleepiness), or caffeine, exercise and adequate lighting (for both). Once fatigue and sleepiness occur, there are shared symptoms that manifest. From this point, symptom monitoring can be used to prevent potential safety incidents. Conclusion Fatigue and sleepiness are similar yet distinct in many ways, and in some instances, it may be difficult to decipher which state is exerting greater influence over observed performance decrements. However, understanding the nuanced differences and the visual aid in Fig. 1 can assist with the development of risk management plans and systems to mitigate work-related risk due to sleepiness and fatigue. Disclaimer The findings and conclusions in this paper are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC). Mention of any company or product does not constitute endorsement by NIOSH. References A list of all references is available in the full paper.

Are fatigue and sleepiness the same? A brief introduction to the differences and similarities, and their implications for work safety

Authored by:
Max Barham, Tim Bauerle, Brianna Eiter

To view this article you must be a member of SME/UCA.

Fall is just around the corner, bringing back hazards of rain and reduced visibility

A big thank you to all of our Industrial Minerals Review authors

Submit to MINEXCHANGE 2027 proceedings and Environmental Division Student Poster Contest

Fall is just around the corner, bringing back hazards of rain and reduced visibility

A big thank you to all of our Industrial Minerals Review authors

Submit to MINEXCHANGE 2027 proceedings and Environmental Division Student Poster Contest

To view this article you must be a member of SME/UCA.

USGS mineral review

Experimental and numerical investigation of methane flame propagation characteristics in a 30.5-m explosion reactor with obstacles

Related Articles

Rare earth elements in the global economy: Usage, recovery and the quest for supply security — A review

A systematic evaluation of localization signals in the advancing openpit mine Aitik

From foundation to future: Revisiting AI integration in mining engineering education through current perspectives of students, educators and industry

Iron ore tailings reprocessing by electrostatic separation plus two-stage froth flotation

Fall is just around the corner, bringing back hazards of rain and reduced visibility

A big thank you to all of our Industrial Minerals Review authors

Submit to MINEXCHANGE 2027 proceedings and Environmental Division Student Poster Contest

Fall is just around the corner, bringing back hazards of rain and reduced visibility

A big thank you to all of our Industrial Minerals Review authors

Submit to MINEXCHANGE 2027 proceedings and Environmental Division Student Poster Contest

Use Single Sign On