A recent study carried out by the US National Institute for Occupational Safety & Health (NIOSH) has shown that airborne transmission of the flu virus can be significantly reduced by maintaining an atmosphere of 40% relative humidity (RH) and above.
It is estimated that over 7.6million working days are lost in the UK each year as a result of flu-related sickness, costing the UK economy over £1.35 billion per annum. Most experts think that flu is spread by tiny droplets created when people with flu cough or sneeze, which can remain in the air for hours.
NIOSH tested the effects of humidity on airborne influenza by “coughing” aerosols of flu virus into a room’s atmosphere from a mechanical manikin at humidity ranging from 7-73%RH, while the air intake from a breathing manikin in the room was monitored.
The air inhaled by the breathing manikin showed that in a room humidity of 23%RH and below the airborne flu virus retained 71-77%...