Investigation on How to Reduce COVID-19 Impacts in Workplaces

This article summarizes what we know and what we need to know about social distancing and its importance in reducing the COVID-19 virus (SARS-CoV-2). Many countries around the world have developed social distancing policies to curb COVID-19 infection rates among their population. The virus that causes COVID-19 is transmitted from human to human, so social distancing is key to mitigating the spread of the illness. According to government and non-governmental organizations reporting on COVID-19 in the literature, there is currently no general consensus regarding social distancing in the workplace. The recommended distances range from 1 to 11 meters. Moreover, neither meteorological parameters nor engineering ventilation methods are taken in account in estimating safe social distancing in the workplace. This study investigates also the importance of using engineering ventilation in healthcare settings, especially during widespread disease outbreaks such as COVID-19. Ventilation can be used to improve indoor air quality in care homes, hospitals, and quarantine locations. Although there are several different types of engineering ventilation, mechanical ventilation is most suitable for reducing the impact and spread of COVID-19 in healthcare and other facilities. Investigation on How to Reduce COVID-19 Impacts in Workplaces. Biomed J Sci & Tech


Introduction
At the end of 2019, a new virus (SARS-CoV-2) appeared in the city of Wuhan, China. It sickened thousands of people first in China and then started sickening thousands of people in other countries, prompting the World Health Organization to declare a pandemic in March of 2020. The WHO called the disease caused by the novel coronavirus "COVID-19", which is short for "coronavirus disease 2019". Over the past several months, COVID-19 has continued to spread around the world, infecting people in more than 150 countries. The rapid expansion of the disease is due to many factors, in particular its biological formation [1], the absence of human immunity, the lack of information concerning the virus, and other physical, chemical and meteorological parameters. Throughout  Most domestic and international borders are also closed. Even without the threat of contracting COVID-19, governments have been paying more and more attention to air quality over the past few decades, both indoor and outdoor. In fact, indoor air quality is related to outdoor air quality. According to scientific studies [2][3][4][5] and recent satellite images, outdoor air quality has improved during the pandemic period. This is because industrial activity has mostly shut down, temporarily slashing air pollution levels around the world [3][4][5].
On the other hand, many countries have been extensively using commercial disinfectants. These chemical products can have a negative impact on human health and on-air quality (outdoor and indoor). Some products used as disinfectants, such as chloride, can also have a deleterious effect on stratospheric ozone. Additionally, air quality can be reduced by solid wastes. During a pandemic period, there is an augmentation of solid wastes. However, these wastes may be improperly managed, as is the case now during the COVID-19 pandemic [6]. Solid wastes that are improperly managed can affect air quality and our environment. Hospitals and other care facilities produce a huge quantity of medical wastes [5]. The medical wastes are mainly composed of gloves, masks, textiles, needles, sanitizers, and disinfectants.
For example, the hospitals in Wuhan produced an average of 240 metric tons of medical waste per day at the height of their initial outbreak, compared to their previous average of fewer than 50 tons. A sudden drop in IAQ has likely resulted from COVID-19related effects. Isolating or quarantining at home has become the global norm nowadays to protect people from the virus, but at the same time a lack of information of how the virus spreads and who is susceptible may be leading to poor IAQ [7]. It is worth noting that while the virus can infect people of any age, the hardest hit demographic currently is the elderly, especially those residing in care homes. The engineering ventilation should be designed according to the specifications of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). More details can be found on the ASHRAE website (https://www.ashrae. org/technical-resources/standards-and-guidelines). To stop the spread of COVID-19, many measures are suggested to be taken, such as frequent handwashing, avoiding the touching of eyes, nose and mouth, using medical and cloth masks, staying home as much as possible, and following social distancing guidelines.
These measures are being taken in order to protect human health, to reduce the impact of the virus, and to provide an environment that is safe to reopen society. In the present study, our investigations are focused on indoor air quality (IAQ). Addressing IAQ is key to protecting human health in an enclosed building. Most people spend more than 90% of their time in enclosed residential, industrial or commercial structures. This percentage has risen dramatically during the COVID-19 pandemic, as millions of people have been mandated to stay at home, including working from home.
The present paper focuses also on social distancing. According to the WHO, social distancing means maintaining at least a 1-meter (approx. 3-foot) distance between people when interacting in the workplace, shops, parks, etc. Social distancing is an important method for protecting human health and reducing the impact of the disease outbreak around the world. This form of physical distancing is recommended to be applied in schools, airports, restaurants, and healthcare facilities, and in many countries, social distancing has now become mandatory.
According to Prin and Bartels (2020), during the 2009 influenza A (H1N1) pandemic, social distancing contributed to a 23% median decline in the cumulative influenza attack rate in the workplace.
Social distancing is important because when someone coughs, sneezes or speaks, they emit small liquid droplets from their nose and mouth. If the person is infected with the novel coronavirus, these droplets can spread COVID-19 to people breathing them in or touching them and then touching their eyes, nose or mouth. During the present study, the importance of social distancing is investigated.
The main objective of this paper is to study the positive impact of air profiles in an enclosed building space (operation room). Air flow speed and direction can play an import role in social distancing, and this factor should be taken into account by healthcare authorities.
In this study, a series of recommendations is given to protect workers and staff in enclosed buildings as well as people outside the building.

Natural Mode Ventilation
The natural mode ventilation is based on air supply coming Natural ventilation is therefore not recommended for hospitals and places of quarantine that house infected patients. A recent incidence of high infection occurred in a care home in the province of Quebec, Canada. All of the staff and residents became infected with COVID-19. The local authorities did not understand this phenomenon, as appropriate distancing was being observed, as well as the wearing of personal protective equipment (PPE). In this case, however, the infection was due to poor quality indoor air that had become contaminated with the virus. The mass of air within a building must be frequently changed according to ASHRAE standards, as building air ages. When air spends too much time in a building, it becomes dangerous for human health. In fact, bacteria and viruses can use the surface of aerosols to spread and thereby infect occupants of these buildings. In the case of the care home in Quebec, the building was not ventilated according to ASHRAE standards.
It was relying on natural ventilation, but this type of ventilation, as mentioned previously, is generally ineffective in large, enclosed buildings. On the other hand, in terms of energy and investment, the natural mode of ventilation is practically free, which is why it is preferred in institutional settings.

Medical Wastes
The medical sector generates copious amounts of different kinds of wastes. This includes discarded surgical gloves, surgical instruments, needles used to give shots or draw blood, masks, sanitizers, disinfectants, gowns, eye protectors (goggles or face shields), other PPE, and medications [8,9]. Medical wastes are classified as hazardous wastes on the basis of their biological, chemical, and physical properties. These materials are either toxic, reactive, ignitable, corrosive, infectious or radioactive, which means they should be stored in a safe place before being moved to their final waste-treatment location and disposed of. The location of waste storage within healthcare premises must be properly determined and sized [10]. It should also be under negative pressure, as these wastes can infect an entire building and its occupants. Hence, medical wastes should be professionally treated according to local bylaws and in adherence to the international convention of hazardous wastes. There are a number of engineering techniques for treating medical wastes, including incineration, thermal treatment, biological treatment, landfilling, neutralization, macro-encapsulation, and deep well disposal [11]. In exploring a broad range of scientific works on the topic, we could find no consensus among the information concerning measurement of social distancing [12][13][14][15][16][17][18][19]. Several articles decribe, define and give advantages of social distancing during the COVID-19 pandemic [12][13][14][15][16][17][18][19][20] and also discuss the benefit of social distancing to reduce the impact of COVID-19 (Figure 1), but the precise measurement is not yet agreed upon by experts in the field.
Unlike the WHO's recommendations, some studies suggest a social distancing measurement of 2 meters between people [21,22], while another study found that, based on simulations, the droplets (100-200µm) can be transported between 8 to 11 meters by the action of turbulent air flow [23]. This distance can also be changed according to droplet diameter ( Figure 2). In other study [24], a droplet with a 100µm was transported up to 3 meters in less than 1 second. Generally, the majority of the countries in the world are encouraging people to stay home throughout the pandemic. The slogan "Stay Home" has been used widely to limit human contact.
Many countries have also imposed more restrictive measures, such as isolation and quarantine. However, social distancing is not determined explicitly by the authorities and governments. Recently, many countries and local authorities set out their plans for a phased ending of coronavirus lockdown, with many of the measures imposed including social distancing.
According to our investigation, physical distancing differs from country to country. For example, in the United States, the Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) have recommended a spacing of 6 feet between people to decrease the spread of COVID-19 in the workplace [25,26]. In Singapore, non-medical people who spend a prolonged period within 2 m of a confirmed case must self-isolate for 14 days [27]. Canadian authorities are requiring a 2-meter distance in most public and commercial locations, and Middle Eastern countries also require 2-meter spacing. In Europe, Col. Rodney Coldren, chief of Preventive Medicine Services, Public Health Command Europe, is asking people to stay as far away from each other as possible. There is as yet no consensus in Europe concerning social distancing. In France, the distance is 1 meter, while in Germany the distance is 1.5 meters.
Chinese authorities have stipulated 1-meter distancing in schools, but social distancing measures in Japan are quite lax.
From the above, it is clear that there is no international consensus on social distancing. To date, social distancing ranges between 1 to 2 meters but can also be as high as 11 meters in relation to droplet spread. The international rules established by authorities, healthcare, and local governments are practically the same for outside (i.e., parks) as for inside (i.e., enclosed workplaces).
Numerous factors should be taken in account to determine social distancing, including meteorological parameters such as wind and air flow direction, temperature, and humidity. Unfortunately, the CDC, OSHA, and WHO have not considered these parameters when declaring their rules. Some countries require barriers between workers or staff in workplaces, and these barriers are considered sufficient to make the workplace "safe".