Effect of aerosol particle size on airborne transmission of infectious disease

Common to almost all pandemics that have claimed millions of lives globally is that the infectious viruses or bacteria have had an ability to spread through the air. This applies, for example, to influenza, smallpox, tuberculosis and, by all accounts, also covid-19. The spread of infection mainly takes place indoors, where people stay close together most of their time. In order to create a healthy built environment, it is therefore important to understand, and thus have the opportunity to influence, the factors that control airborne virus infection in built environments. With support from Formas, we have for the past ten years worked with measurements and analysis of airborne viruses. in an indoor environment. Among other things, we have detected winter vomiting virus in the air, studied the virus' survival in airborne particles and identified indicators of high virus levels. The technology we have established we now want to use for a further analysis that includes more viruses (SARS-CoV-2, influenza, RS) and more factors that affect airborne infection in the indoor environment. The goal of this project is to thereby contribute to a reduced spread of airborne infection indoors. Buildings generally have a pleasant, well-temperate climate, which is appreciated by both humans and microorganisms. A building shields from the stresses of the outdoor environment in the form of constant changes in temperature and ultraviolet radiation. In the air indoors, unlike outdoors, an accumulation rather than a dilution, of viruses takes place. Despite enormous societal costs caused by the spread of infection, it is rarely taken into account when designing indoor environments. Knowledge is too small about how the transport of biological particles through the air is affected by factors such as position of ventilation devices, air content of particles, humidity, ceiling height, open office landscapes, toilet location, doorways or heating movements. Good hand hygiene is usually considered the single most important preventive measure for infectious diseases. However, the air is an important route of transmission and hand washing does not protect against inhaled microorganisms. When it comes to airborne infections, we find it more difficult to formulate effective measures because there are many uncertainties about how infectious agents spread and survive air transport under different environmental conditions. For example, we still have very little knowledge about how the virus gets into the air, how far they are transported and survive in an indoor environment and how much we inhale. Viruses are not only airborne during sneezing, but also during a number of other indoor activities such as flushing the toilet, making bed and moving. Much of this can be influenced. Increasing understanding of this is today a challenge that there are realistic opportunities to tackle with interdisciplinary approaches. We have for a long time built up a close collaboration between aerosol research, virology and infectious disease medicine at Lund University in order to reduce airborne infection indoors. This project consists of both field measurements in an indoor environment and controlled laboratory studies of airborne viruses. The purpose of the field measurements is to determine the sources, transport distances and size of the airborne particles that contain viruses. During the experiments in the laboratory, we investigate how the virus survives in air in particles of different sizes. This gives us an overall picture of the airborne virus' transport cycle from source, via transport, to survival and finally disposal. The research we have conducted so far on airborne infection in indoor environments has been in great demand by companies (ventilation manufacturers, air purifiers, architects, cleanroom industry), healthcare (infection control, care hygiene, infection medicine) and a wider public who want a healthier environment at home or in the workplace. It is possible to create a fresher indoor air and thus a healthier society. This project answers some of the questions that exist about how we can do this most effectively. This gives us a better basis for the design and change of existing and future buildings. to survival and finally disposal. The research we have conducted so far on airborne infection in indoor environments has been in great demand by companies (ventilation manufacturers, air purifiers, architects, cleanroom industry), healthcare (infection control, care hygiene, infection medicine) and a wider public who wants a healthier environment at home or at work. It is possible to create a fresher indoor air and thus a healthier society. This project answers some of the questions that exist about how we can do this most effectively. This gives us a better basis for the design and change of existing and future buildings. to survival and finally disposal. The research we have conducted so far on airborne infection in indoor environments has been in great demand by companies (ventilation manufacturers, air purifiers, architects, cleanroom industry), healthcare (infection control, care hygiene, infection medicine) and a wider public who wants a healthier environment at home or at work. It is possible to create a fresher indoor air and thus a healthier society. This project answers some of the questions that exist about how we can do this most effectively. This gives us a better basis for the design and change of existing and future buildings. healthcare (infection control, care hygiene, infection medicine) and a wider public who want a healthier environment at home or in the workplace. It is possible to create a fresher indoor air and thus a healthier society. This project answers some of the questions that exist about how we can do this most effectively. This gives us a better basis for the design and change of existing and future buildings. healthcare (infection control, care hygiene, infection medicine) and a wider public who want a healthier environment at home or in the workplace. It is possible to create a fresher indoor air and thus a healthier society. This project answers some of the questions that exist about how we can do this most effectively. This gives us a better basis for the design and change of existing and future buildings.