Dry Environments: The Influence of Low Humidity on Comfort and Health

Individuals are routinely subjected to dry environments. These conditions may result from geographic areas, the heating of indoor spaces, or specialized settings (e.g. commercial aircraft cabins). This paper examines the affect of low humidity from two perspectives: comfort and health. Results indicate that the dry-bulb temperature is only 7.8 times more important than relative humidity (rh) in determining the subjective thermal response, and that rh has a greater role in determining how men feel than how women feel. Additionally, it was shown that a perceivable level of annoyance is experienced by both wearers and nonwearers of soft contact lenses at or below 30% rh, and this effect becomes most pronounced after four hours. Other findings indicated that the perception of varying odor intensity levels (e.g., cigarette smoke) is higher in dry environments; several studies are also reported showing the health related benefits of humidification.