Fewer viruses and germs in indoor air
There are various ways of doing this. UV disinfection lights, for example, are designed to use UV rays to kill germs and inhibit the ability of bacteria and viruses to infect and reproduce. Ozone generators are also said to have similar effects: according to manufacturers, the devices suck in oxygen molecules that are then split by an electrical charge to create ozone, which destroys viruses and bacteria. So just set up a machine and you’re good to go? It’s not quite so simple. Since UV rays can damage skin and eyes, experts advise caution. ‘Scientific analyses of possible health-related consequences are still at an early stage,’ say sources such as Germany’s Federal Office for Radiation Protection. Nor is the use of ozone without controversy. For example, the gas may cause symptoms of irritation or bind other contaminants, experts warn.
High performance air purifiers are the current favourites among specialists and practitioners. Studies by the Institute of Fluid Mechanics and Aerodynamics at the Universität der Bundeswehr München (UniBw), for instance, have shown that indoor air cleaners can effectively reduce the risk of indirect infection by aerosols. ‘High-performance indoor air cleaners with a combination of F7 and H14 filters, such as the TAC V+, can easily keep the aerosol concentration in small and medium-sized rooms at a low level,’ says Prof. Dr Christian Kähler of the Institute of Fluid Mechanics and Aerodynamics at the UniBw. ‘These devices are therefore ideally suited to maintain a low viral load in areas such as classrooms, shops and waiting or examination rooms without having to worry about opening windows and impairing the well-being of the people in these rooms.’ Kähler also notes that this ensures a reduction of the viral load: ‘Furthermore, they also ensure a real reduction in the virus load, which often cannot be guaranteed with free ventilation provided by opening windows. Although indoor air cleaners and air treatment units minimise the indirect risk of infection, they do not protect against direct infection, which means that additional protective measures are essential.’ However, he adds, filter technologies cannot provide complete protection from infection. ‘For this reason, it is also important that we continue to keep a safe distance from other people or that we wear mouth and nose coverings. People should ideally wear particle-filtering masks or protect themselves against direct infection with transparent protective screens.’