Relative humidity promotes the spread of SARS-CoV-2 coronavirus through aerosol particles in the air.
Researchers from the Leibniz Institute for Tropospheric Research in Leipzig (Germany) and the National Physics Laboratory in New Delhi (India) conducted a study on this. The results of their study were published in the journal Aerosol and Air Quality Research.
Experts have analyzed 10 studies on the impact of the environment on viral infections. It has been found that a relative humidity of 40 to 60 percent can reduce the spread of viruses and their absorption through the nasal mucosa.
For a long time, large droplets in the air when infected people coughed and sneezed were called the main route of transmission of the virus. Heavy drops fall to the ground very quickly and can only travel short distances. Based on this, it is recommended to wait at least 1.5 meters with other people. However, there have been recent cases of COVID-19 infections that appear to be caused by a large number of people in the same room at the same time.
It is known that small droplets with a diameter of five micrometers can stay in the air for nine minutes. At high humidity, more water molecules adhere to the particles, causing them to grow and settle faster. The results of a new study showed that humidity also affects the behavior of microorganisms in the droplets, their survival and the degree of inactivity. Dry air moisturizes the nasal mucosa less and facilitates the entry of viruses.