Effects of COVID-19 on Sense of Smell: Human Factors/Ergonomics Considerations

Abstract

Objective We review the effects of COVID-19 on the human sense of smell (olfaction) and discuss implications for human-system interactions. We emphasize how critical smell is and how the widespread loss of smell due to COVID-19 will impact human-system interaction. Background COVID-19 reduces the sense of smell in people who contract the disease. Thus far, olfaction has received relatively little attention from human factors/ergonomics professionals. While smell is not a primary means of human-system communication, humans rely on smell in many important ways related to both quality of life and safety. Method We briefly review and synthesize the rapidly expanding literature through September 2020 on the topic of smell loss caused by COVID-19. We interpret findings in terms of their relevance to human factors/ergonomics researchers and practitioners. Results Since March 2020 dozens of articles have been published that report smell loss in COVID-19 patients. The prevalence and duration of COVID-19-related smell loss is still under investigation, but the available data suggest that it may leave many people with long-term deficits and distortions in sense of smell. Conclusion We suggest that the human factors/ergonomics community could become more aware of the importance of the sense of smell and focus on accommodating the increasing number of people with reduced olfactory performance. Application We present examples of how olfaction can augment human-system communication and how human factors/ergonomics professionals might accommodate people with olfactory dysfunction. While seemingly at odds, both of these goals can be achieved.

Why human olfaction should not be modeled on theories and tasks of vision

“…This analysis should not be understood as a claim that smells cannot be used as rough indicators of locations in environments with aerial stability. Some examples of how smells can be used to help people find around in homes for the elderly have been described (e.g., Köster et al, 2014 ; Cameron et al, 2021 ). But outside, where the wind blows and odorous materials are constantly mixed, animals with their noses 1.8 meters above the ground would be in dire trouble by relying on olfactory signals to guide wayfinding.…”

Olfactory-related quality of life impacts psychological distress in people with COVID-19: The affective implications of olfactory dysfunctions

“…COVID-19 is mainly characterized by symptoms of fever, cough, and shortness of breath, as well as by the onset of chemesthesis, smell and taste dysfunctions, particularly anosmia and hyposmia. In addition to being iatrogenic as to the overall individual's mental health ( Xiong et al, 2020 ; Salari et al, 2020 ), COVID-19 is indeed associated with loss or impairment of the sense of smell ( Cameron et al, 2021 ). Therefore, the outbreak of the COVID-19 witnessed a renewed interest in the research on olfactory dysfunctions and the effects they have on the individuals affected by the disease.…”

Downstream natural gas composition across U.S. and Canada: implications for indoor methane leaks and hazardous air pollutant exposures

“…Furthermore, population-level disparities in smelling acuity likely exist mediated by older age [12,13], and infections (e.g. COVID-19) [14][15][16][17][18]. This indicates cause for concern regarding the sole reliance on 'normal sense of smell' to protect from NG leaks.…”

“…Furthermore, age is an important determinant for gas leak detection with an estimated 31% of adults aged ⩾70 years misidentifying odorized NG in the 2012 U.S National Health and Nutrition Examination Survey [12,13]. And although few studies have examined the effects of COVID-19 on NG detection, early results suggest that patients who have recovered from COVID-19 lose some ability to detect NG odorants [14][15][16][17][18]. As the only mandated mechanism for rapid gas leak detection, the efficacy of NG odorization is understudied particularly in light of scrutinized methane emissions budgets and coemitted NMVOCs including benzene [8].…”