Comparative analysis of physical methods of transport disinfection

Abstract

Transport is an object of mass concentration of people where workers and passengers are likely to be exposed to pathogens of infectious diseases. 95% are diseases that do not respond effectively to the effects of specific prophylaxis, influenza and acute respiratory viral infections. Currently, measures to contain the infection have led to a restriction of transport activity. In such conditions, the development of effective ways to prevent the occurrence and spread of infectious diseases transmitted by airborne droplets, not controlled by means of specific prevention, as well as the preservation of the health of transport industry workers, is particularly relevant. The aim of the study is to determine the location and type of air disinfection device in the driver's cabin of a railway vehicle and the passenger compartment of a sitting car with various breathing options (natural exhalation, cough, sneezing). To determine the location and capacity of the decontamination plant, the mathematical method of gas-dynamic calculations using solid-state three-dimensional models was used. The study was performed in the SolidWorks software package, using the FlowSimulation module to solve the system of nonlinear Navier-Stokes equations. The trajectories of air flows from human breathing in the cab of the vehicle are calculated taking into account the influence of ventilation. Research on the effectiveness of disinfection was carried out by a certified laboratory in the operating conditions of the vehicle. The results of the calculation allowed us to establish that it is advisable to place devices for physical disinfection of air in the cab of the vehicle at the level of the information panel on the left side or directly in the center. The basis for choosing the technical characteristics of the device for air disinfection should be information about the maximum speed of particles approaching the information panel, which is equal to 2.2-3 m/s. The safest method of disinfection of the air environment of vehicles is the use of closed UV radiation installations, the effectiveness of which is confirmed in the course of a full-scale experiment. It is concluded that the formation of an infection zone when an infected person is in the cab or cabin of a vehicle largely depends on the duration of his stay in the cabin, the intensity of breathing and the use of personal protective equipment. The advantage of closed UV radiation installations is the simultaneous provision of high disinfection efficiency and satisfaction of all safety requirements (chemical, environmental, fire, electrical, etc.), as well as the possibility of using the method in the presence of people. The analysis of the regulatory and technical documentation showed that UV irradiators are the only type of disinfection equipment that meets the requirements of domestic legislation in the field of sanitary and epidemiological welfare.