Could humidity hold the key to flu control? The latest research indicates it could affect transmission and survival of viruses
According to the latest research, humidity could have a significant part to play in the transmission and survival of the influenza A/H1N1 in areas where large numbers of people congregate such as in hospitals. This could have huge ramifications for the humidification industry and regulations for the built environment.
‘Catch it, bin it, kill it’ may be one form of defence but are there any clinical trials to substantiate this cause and effect?
Researchers have known since the 1940s - with proven test results- that low humidity levels increase the survival time of the flu virus. This, together with airborne transmission which is also affected by low humidity has been suggested as a factor for the seasonality of flu (Hemmes JH, Winkler KC, Kool SM, Virus survival as a seasonal factor in influenza and poliomyelitis published in 1960) The droplets expelled from a carrier, being water based, shrink rapidly due to evaporation in an environment that is less than 40% relative humidity (RH) and so remain airborne for long periods.
What about new research? Dr Jeffrey Shaman at Oregon State University cites absolute humidity as the defining factor over relative humidity.
Are we saying then that lots of money could be saved on vaccinations by the mere inclusion of humidity into a building? No, but the time it takes to develop the vaccine and the cost to individual organisations each year through lost man hours due to seasonal colds and flu must be taken into consideration, along with the reduced chance of catching swine flu.
This latest research has far reaching implications and re-opened the debate on the benefits of humidification. The extent to which moisture has a part to play in our environments is well documented but its impact on our health poses many questions the answers of which could have a significant influence on our building’s environments.
(Free selection software including psychrometric charts is available from Vapac Humidity Control dave.mortimer@eaton-williams.com for relating absolute humidity to relative humidity values.)
An-depth article Controlled humidity could hit flu hard appears in the February issue of IHEEM's Health Estates Journal www.healthestatejournal.com