Investigating the effect of wearing masks on office work in indoor environments during a pandemic using physiological sensing

Highlights

• Physiological sensing is effective to study the effect of wearing a mask

• The effect of wearing a mask varies across individuals

• Overall lower mental workload is observed while people performing tasks with masks

• Better task performance is observed without wearing a mask for most people

• No general pattern to conclude the difference between cloth and surgical masks

Abstract

The spread of pandemics has adverse effects on the lives of people in various ways. For people who need to work in the office and other indoor environments, wearing a mask has become an essential precaution to reduce the spread of the virus and thereby the risk of disease transmission. Therefore, it is important to understand how wearing a mask will affect people while they are performing daily office work. This paper aims to investigate the effect of wearing a mask on the physiological responses and task performance of those who work in office environments during the pandemic period. The two most commonly used masks (i.e., cloth and surgical masks) are chosen for evaluation. The work engagement, mental workload, skin conductance level (SCL), heart rate (HR), as well as the overall performance of 20 subjects while they are completing simulated office tasks are collected and analyzed. Although the results vary across different individuals, they reveal that wearing a mask during a pandemic period will potentially reduce the mental workload and SCL of people for specific types of tasks. In addition, the task performance (correct number and correct rate) of the subjects is worse when wearing a mask, which is highly correlated to the results of the mental workload and SCL. However, there is no one-size-fits-all pattern to conclude the effect of wearing masks on work engagement and HR. This study provides a valuable reference for those who need to wear a mask while working.

Introduction

Due to the spread of the new coronavirus (COVID-19), people's lives have been affected in different ways. Indoor environments are particularly important to slow the spread of the virus, resulting in additional requirements of maintaining good indoor air quality [[1], [2], [3]] and wearing face coverings in common places like office environments and public gatherings [4,5]. For example, as recommended by the United States Centers for Disease Control and Prevention (CDC), people should wear masks in public events, gatherings, or anywhere with other people, as masks can provide a barrier to respiratory droplets and thus prevent the spreading of COVID-19 [6]. The Occupational Safety and Health Administration (OSHA) recommends employees wear cloth face covering at work to reduce the spread of the virus and thereby the risk of disease transmission [7]. Similarly, the World Health Organization (WHO) also considers wearing masks as a key measure to suppressing transmission of the pandemic and saving lives [8].

To overcome the economic recession during the pandemic period [9], people's working styles have become more and more flexible. For example, employees can choose to work from home and only return to the office seldomly [10]. Nevertheless, not every home has a suitable workplace [9] and home office work requires more online effort and greater concentration during communication, thereby generating visual, auditory, and mental overload [11]. Moreover, it is unavoidable for some employees to go back to the office from time to time to perform professional tasks [12,13]. Therefore, it is crucial to understand the potential effect of wearing a mask on people's productivity and wellness while they are performing work in office-type settings.

Although the efficacy of face masks in preventing the spread of the respiratory virus is confirmed by previous research [14], it may also cause some adverse effects on people [15]. For example, wearing an efficacious mask will affect the respiration cycles, and lead to increased expired air retained within the breath zone [16]. The concentration of carbon dioxide (CO₂) in the breath zone will rise significantly after wearing a face mask. This may cause an increase in physiological stress due to the low level of oxygen [17]. In addition, previous studies have shown that wearing a mask for a long time may influence people's health and comfort due to the poor ventilation underneath the mask [15,17,18]. Despite some general effects of wearing masks have been studied, there is a lack of systematic investigation to understand the effect of wearing masks on the performance and mental health of individuals who work in office-like indoor environments (the setting, social features, and physical conditions in which people could perform office work [19]). This raises an important question: since wearing masks may adversely impact the breath zone air condition in different aspects, how will it affect the physiological responses (e.g., work engagement, mental workload, and skin conductance level) and task performance of people while they are performing office work?

To answer this question, an experiment is needed. Based on the literature, specific types of physiological data are correlated with human psychological states. For example, the brain signal is correlated with psychological stress [20], and galvanic skin response (GSR) is proven as a good indicator of detecting emotions [21]. Therefore, instead of collecting data in subjective approaches such as questionnaires, the experiment is designed based on physiological sensing. The experiments are conducted in a controlled lab environment, and computer-based cognitive tasks are designed for the subjects to simulate typical office tasks. Meanwhile, the subjects' physiological responses and performance are recorded. Based on previous research, work engagement (“a positive, fulfilling, work-related state characterized by vigor, dedication, and absorption [22]”) and mental workload (“the ‘costs’ a human operator incurs as tasks are performed [23]”) can directly affect the productivity of the employee [[24], [25], [26], [27]]. In addition, skin conductance level (SCL) and heart rate (HR) are found relevant to the general changes in autonomic arousal [[28], [29], [30]]. Therefore, these physiological indicators are measured under the scenarios with and without masks. Based on the guideline of CDC and OSHA, the two most common types of masks used during the pandemic, cloth and surgical masks [6,7] are used in the experiments. The collected experimental data is further analyzed and compared to provide insights into the effect of wearing masks on the subjects. The objectives of this study can thus be summarized as: (1) to investigate the effect of wearing different mask types on work engagement; (2) to understand the effect of wearing different mask types on the mental workload; (3) to investigate the effect of wearing different mask types on other important physiological responses (i.e., SCL and HR); and (4) to compare the task performance of the subjects before and after wearing a mask.

This paper is organized as follows. Section 2 reviews the related work. Detailed methodology is described in Section 3, which includes two major parts: (1) experimental design, and (2) data collection and process. Section 4 shows the experimental results and analysis, and Section 5 provides a discussion of the results and limitations, followed by conclusions in Section 6.