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Nov 03, 2020

Humidity and the risk of infections

Winter is approaching, and it leads to dry indoor climate in large parts of the world. The contamination risks and the spread of aerosols increase in dryer climate. 

Scientific evidence shows that a mid-range air humidity has benefits for human health. With a humidity lower than 40% RH, viruses infect us more easily. In addition, airborne droplets float for longer and dries, enabling the virus to survive for longer in low air humidity environment. 

Dr. Stephanie Taylor, founder of is calling out to WHO to act and she is recommending a minimum lower limit of indoor humidity in public buildings to reduce respiratory infections. In an ideal indoor climate, our respiratory immune system functions effectively, and airborne droplets will be heavier and fall out of the air.

Researchers from Riken and Kobe University have used the Fugaku supercomputer to simulate the flow of viruses in a variety of indoor climates. The simulations showed a doubling of aerosols particles in a dry climate (30% air humidity) compared to an environment with 60% or higher air humidity. 

Courtesy: Riken/Kobe University

These findings suggest that the use of humidifiers may help limit infections during dry indoor air periods. Looking specifically at operating rooms, humidifiers are not always used since countries that have not yet installed such equipment claim that they only see very small differences in surgical site infection rates, if any, between different seasons. This is an on-going debate where more data is needed.

 Still, the benefits of indoor air humidity between 40 to 60% RH at hospitals may prove to be a reduction of healthcare associated infections and shorter length of stay for patients. With a reduction of infections and shorter hospital stays, hospitals improve patient outcomes and maximize their revenues. Furthermore, too low humidity may cause problems that relate to storage of sterile goods as well as reliable use of electronic medical devices.

 Apart from an ideal indoor air humidity there is a need to secure many hospital areas from transmission of airborne contaminants by better air flow management. Those contaminants may be any combination of bacteria, virus or particles and the goal is to establish safe working conditions for staff as well as safe and welcoming areas for patients. To avoid virus and bacteria to spread in the most sensitive areas of the hospital filtered air must be sourced to these rooms to achieve the best climate and cleanliness. By controlling the airflow and using gravity in key spots that need to be kept very clean, Opragon offers a complete ventilation system for whole departments and floors in your hospital buildings.

Contact us for more information on how we can help you to create a comfortable and safe environment at your hospital!