Covid-19 Bow-Tie model

Since the beginning of human creation, safety barriers have been used to protect people and property from enemies and natural hazards. One of these risks is the emerging and highly contagious disease of Covid-19. This pandemic has left very deep and severe consequences and effects in various fields such as economic, medical, social, cultural, sports, educational, military, and security all over the world, including in Iran, So, the health of human society has faced a big challenge.  The general public and workers are always at risk of being exposed to this virus and getting infected. Awareness of risk is the best way to prevent and slow down the transmission of the COVID-19 pandemic, which can be achieved through risk assessment, and effective risk communication is an important measure to control this disease. Various organizations such as OSHA and WHO have given recommendations to employers to prevent the spread of the coronavirus in different workplaces, which can be in the form of preventive and control strategies.  Hollnagel describes two main functions for safety barriers: prevention and protection. Barriers are placed before the start of a specific event as a means of prevention. As a result of the intervention of this type of barrier, it is assumed that the accident (corona pandemic) will not happen, or it will slow down its progress on the way to becoming an accident (pandemic). Barriers considered after the occurrence of a specific initial event are used as a means to protect people and systems from the consequences of a pandemic [1]. One of the most famous models for risk assessment in industrial health and safety is the bowtie model and layer of protection analysis (LOPA). In the bow tie model, the left cone represents the possible causes and events leading to the disease and introduces the preventive layers that the system has prepared to deal with the pandemic. The cone on the right side also has the role of reducing the consequences, which according to various studies, in this editorial, we are going to express preventive and mitigation approaches in industries. People in industries have different responsibilities that may be exposed to this virus according to the type of job, relevant organization, and population density. In general, the applicability and simplicity of implementing individual and management controls are much higher. The layers are constantly evaluating the effectiveness of their actions in a dynamic system and will make new decisions according to the conditions, which is by the Deming cycle in management systems.  Therefore, it can be said that the Covid-19 pandemic is a problem with a medical shell and a systemic core; so, leaving the solution of the problem to the responsibility of the healthcare system alone does not solve the problem. On the other hand, using different specialties with a systemic approach can create a stronger barrier against the spread of this disease and its resulting damages [2].  Fig 1. Covid-19 bow-tie model in workplaces According to Figure 1, preventive measures for corona disease include engineering, management, personal and health measures, and vaccination. Reactive measures against the corona pandemic also include having an emergency response plan (ERP), remote working, resting at home in case of symptoms of coronavirus infection, using video conferences to hold meetings, canceling unnecessary meetings, that management participation can be considered the main factor in preventing the coronavirus. Individual and managerial actions are important indicators in both proactive-reactive layers. The application of engineering measures, especially the use of artificial intelligence and information technology, can increase the chance of identifying the behavior pattern of people and the virus by analyzing big data. Designing a ventilation system with certain average ventilation is one of the basic measures of engineering in controlling pandemics. Using facial recognition instead of fingerprints in industries can also reduce the level of contact with contaminated surfaces. Providing continuous training, developing guidelines, and considering the appropriate budget to deal with Corona are also management measures in the field of preventing this pandemic.  The classification of personal and health measures plays an effective role in the prevention of covid disease, which should be considered in industries. These include personal protective equipment, use of hand washing soap and disinfectants, maintaining proper physical distance, not using shared tools and equipment, and screening people by various thermometers and laboratory tests (Rapid Test-PCR).   Vaccination is also a very important and valuable measure that can be used to prevent infectious diseases at a low cost. The side effects of corona vaccine are negligible compared to the benefits of using it. The side effects of corona vaccine may lead people's minds to unfortunate events, while these side effects generally include: headache, lethargy, body pain, bruised feeling in some places, etc., and will last between 1 and 2 days. But the important point is that the injection of corona vaccine will ensure that people will never get severe corona as long as their body is vaccinated. In addition, the injection of the vaccine will prevent people from dying due to the coronavirus.