Maintaining social distancing and wearing masks isn’t sufficient enough to curb the spread of the coronavirus. An Indian-German group of scientists recommend that controlling the humidity of indoor spaces and keeping it between 30-40% can play a key role in our fight against the coronavirus.
Controlling the humidity of an indoor environment in hospitals, workplaces, public transport is extremely necessary as stated by the researchers from the CSIR National Physical Laboratory, New Delhi. This study has been published in the journal Aerosol and Air Quality Research. Humidity can be defined as the level of water vapors in the air at a given temperature. The study particularly drew attention to the effects of humidity on the coronavirus.
The scientists claim that if we can reduce the relative humidity in a room to 30-40% then it can significantly reduce the absorption of the Sars-CoV-2 through the membrane of our nose (nasal mucous membrane). The droplets released when we speak are up to five micrometers in diameter and can float in the air for up to nine minutes. The co-author of the study from the Leibniz Institute of Tropospheric Research in Germany, Dr. Ajit Ahlawat, says, “In aerosol research, it has long been known that air humidity plays a major role-the more humid the air is, the more water adheres to the particles and so they can grow faster. So, we were curious -what studies have already been conducted on this.”
As per the researchers, humidity also affects the virus’ ability to reproduce and stay alive. It can also have an impact on the inactivation of the surface of the virus. Therefore, humidity can play a role in the transmission of the coronavirus through dry indoor air. Dr. Ahlawat says, “If the relative humidity of indoor air is below 40%, the particles emitted by infected people absorb less water, remain lighter, fly further through the room, and are more likely to be inhaled by healthy people. In addition, dry air also makes the mucus membrane in our noses dry and more permeable to viruses. Heating the fresh air also ensures that it dries. In cold and temperate climate zones, therefore, the indoor climate is usually very dry during the heating season. This could encourage the spread of viruses.”
If the humidity of the air is high then the droplets fall to the ground faster and are less likely to be inhaled. Another co-author of the study, Dr. Submit Kumar Mishra, CSIR National Physical Laboratory, New Delhi, says, “A humidity level of at least 40% in the buildings and local transport would therefore not only reduce the side-effects of COVID-19 but also of other viral diseases such as the seasonal flu. Authorities should include the humidity factor in future indoor guidelines.”