Continuous exposure to a humidity level below 40% RH will negatively affect the comfort and health of school staff and students. A high absence rate and decrease in productivity are common results.
When the humidity in schools is outside of optimal range of 40-60% RH the most commonly known first effect of dry air is electrostatic shock. Further, less apparent symptoms can include itchy skin, sore eyes and sinuses, contact lens discomfort, dull hair, and increasing dehydration.
Maintaining optimal humidity levels, however, is proven to prevent these effects and furthermore decrease the danger of airborne viruses, such as influenza, transmitting in classrooms and office environments.