THE atmospheric humidity is, by definition, the amount of water present in the air in the form of vapor, that is, in addition to the various gases that make up the atmosphere, it is also possible to find water in its gaseous form in the environment where we live. This substance is essential to regulate climate dynamics and also help us in various biological processes.
But what is the difference between air humidity and relative humidity?
THE relative humidity, a term frequently used in the dissemination of weather forecasts, is an atmospheric element referring to the saturation of water present in the air. To understand it, it is necessary to consider the following premise: when the absolute air humidity is greater than 4% (that is, when there are four parts of water for every hundred parts of air), it will saturate and the water will precipitate. However, depending on the temperature variation, the Saturation Point of the air can be higher or lower.
In this sense, the relative humidity is the amount of water present in the air in relation to its saturation point
. So, when we say that the relative humidity of the air is 60%, it means that the air has 60% of its maximum water capacity.If we consider, therefore, that the air saturation point is 4%, as mentioned above, then, when the relative humidity is 60%, the absolute humidity will be 2.4%. Consequently, when it is raining, it means that the relative humidity in the room is at its maximum percentage.
In addition to interfering with weather conditions, the air humidity it also changes weather conditions. In environments where humidity is higher, temperatures tend to vary less, with less fluctuation throughout the day. The reverse process happens when the air is drier.
Relative humidity and health
Very humid environments are considered uncomfortable by people, as they make it difficult for the body to perspire, in addition to giving the feeling of a more “stuffy” environment. On the other hand, the extreme reduction in humidity levels also has effects that can harm our health, as when the air is too dry, we feel the rapid loss of water in our body, in addition to the dehydration of the airways and mucous membranes.
Low air humidity levels are classified as follows:
From 20% to 30% - State of Attention: it is recommended, in this type of situation, not to carry out physical activities or exert too much effort during the hottest hours of the day, between 11:00 and 15:00 at regular time.
From 12% to 20% - Alert Status: the best thing, in this case, is not to make great efforts between 10 am and 4 pm, consume plenty of water, avoid very crowded and closed environments and, if necessary, use saline solution for the eyes and nostrils.
Below 12%- Emergency state: all recommendations of the above states must be maintained, in addition to avoiding physical exertion as much as possible throughout the day. It is recommended that you try to humidify closed places with specific appliances or even wet towels.
By Me. Rodolfo Alves Pena
Source: Brazil School - https://brasilescola.uol.com.br/geografia/umidade-atmosferica-umidade-relativa-ar.htm