Indoor humidity and COVID-19
Our daily and work activities have moved directly indoors, so it is worth finding out how indoor humidity can affect our health. Studies have shown that increasing indoor humidity can help deactivate coronavirus COVID-19 particles from spreading. It is during the cold winter months, when the premises are mostly closed and heated, that the humidity levels can decrease by up to 20%, and unfortunately, the COVID-19 virus has been shown to remain viable in these low humidity conditions. However, too much indoor humidity can also cause health problems. For example, viruses are known to spread more easily at humidity levels above 60%. So what is considered high humidity and what is a safe indoor humidity level? Joseph G. Allen, an associate professor at Harvard University’s Faculty of Public Health, emphasizes that maintaining 40% to 60% humidity in the room can help reduce the survival of the COVID-19 virus.
COVID-19 virus transmission and the effects of dry air on human health
It is during the winter months when the heating appliances are in full mode, you can feel extremely dry indoor air and the first signs are dry skin and lips, and this can be followed by the spread of the virus. Based on scientific studies on viral transmission, we know that dry air can promote the movement of viruses in the air. When an infected person coughs, sneezes, breathes, or talks, they emit small respiratory droplets into the air. Dry air causes these droplets to evaporate faster, forming smaller virus-carrying particles that can stay in the air for a longer time and travel through larger spaces. Their smaller size may also allow them to penetrate mask materials more easily, according to The National Institute for Occupational Safety and Health (NIOSH).
Dry air can also affect our immunity system, increasing susceptibility to different infections spread by air, not only COVID-19 but also influenza and colds. This air can dry out the mucous membranes of the nose and throat, creating microcracks that can make it easier for viruses to cross our protective barrier and enter the body.
Ways to affect the humidity level in the room
We can adjust the levels of humidity and improve air quality, for example, by ventilating the room, which may be a little more complicated in cold weather, but is recommended several times a day, with the window fully open for a few minutes. Humidity is also particularly well increased by houseplants with rich foliage, especially ferns, figs, and ivy. Electric humidifiers can also be an additional helper, maintaining optimal humidity in the fight against dry air. These are just a few solutions, but, as we have already mentioned, the optimum humidity level must always be maintained. Various monitoring sensors are available to assess the humidity level in your home or workplace, but for a complete assessment of the room, it is possible to perform indoor air quality testing.
“It is not possible for humans to control the outdoor climatic conditions which have allowed this coronavirus to cross species boundaries. However, we are able to manage the indoor environment to support our health and reduce viral disease by regulating critical indoor air factors such as temperature, humidity, air exchange rate, and fresh air content. When we maintain indoor temperatures at 20 to 24°C for comfort, it is essential that we decrease our risk of infection by maintaining healthy levels of air humidity and ventilation,” said Taylor S., a graduate of Harvard Medical School in Boston, who has been involved in advanced research that effects of the built environment and indoor air quality on acute and chronic diseases) and Hugentobler W. (studied medicine at the University of Zurich, Switzerland, started research on the interaction between moisture and influenza virus).