2.1. Person-to-Place Interactions in Post COVID-19 Workplace Reopening Scenarios
The IoCT offers various use cases based on the digital monitoring of the physical world and humans using smart sensors that collect and deliver information. For this paper, we explored different COVID-19 transmission risks in miscellaneous workplace reopening scenarios. “Close contact” with a COVID-19 patient, which mostly occurs indoors, was one of the most common methods of COVID-19 transmission [4,25]. Based on our literature review, COVID-19 “close contact” was defined as contact occurring within a period of time longer than 15 min, and a physical distance of less than 2 metres in cases of face-to-face interaction [25]. When sharing the same space, viruses can spread via air, objects, or floor even after two to three days if protective equipment is not used, or disinfection carried out [4]. A digital timely proximity tracing system can effectively limit the spread of contagious diseases by collecting information about people or places that an individual (with confirmed or suspected infection) may have had close contact with or had been to [14]. If a person with COVID-19 was in close proximity to a place, those affected locations (e.g., businesses, public sites, or buses) would then be considered contaminated places (geospatial features). This geospatial information can be used to help in closing, disinfecting, alerting, and defining appropriate safe paths and neighborhoods. For example, if a location is popular with families or the elderly, additional facilities and organizations in the area may need to be alerted to possible exposure in their neighborhood. Health workers will receive timely and relevant alerts to close off and disinfect the actionable list of contaminated places to prevent further transmission. Moreover, organizations at each location can be provided with forms to send to their staff, customers, or visitors informing them of possible contamination, and requesting that they complete a contact trace survey for health authorities.
Three important questions in COVID-19 risk evaluation are: “Who was in close contact with the COVID-19 positive person?” and “What places did the COVID-19 positive person visit, and who else visited those places after that?” The first question can be automatically queried using person-to-person contact tracing. The second question addresses the main focus of this paper which is person-to-place contact tracing. If a COVID-19 positive person was in close proximity to a place, those affected locations (geospatial features such as businesses, or public sites, or buses) are considered to be potentially contaminated places. This information is useful for advising people on safety measures, self-quarantine, and for issuing cleaning alerts. As shown in Figure 1, both people and places, as well as duration of contact, play an important role in the pattern for COVID-19 spread.
The primary step when assessing the COVID-19 virus transmission scenarios is determining the factors affecting the risk of COVID-19 spread. According to [26], COVID-19 risk prevention and control depend on population flow. For this research, the epidemic risk status is assessed based on three levels of personnel flow strategies: (1) Staying at home, temperature monitoring, and traffic control; (2) Wearing a mask and restricting gatherings; and (3) Strengthening health management. Additionally, based on existing studies from both the World Health Organization (WHO) [27] and the Government of Canada website [28], the number of active virus particles in a place is considered to be the most critical factor in determining the risk of infection. Virus particles live for different lengths of time which vary depending on several factors, especially with regards to the composition of different surfaces. To identify and limit the risk pattern of COVID-19, a range of use cases can be considered that utilize the interactions of people, places, and available sensor information for a workplace. The following table (Table 1) sums up the office cleaning use case using person-to-place scenarios for post COVID-19 workplace reopening.