When humidity is low (< 30%)
Germs and Viruses
Due to low humidity, germs & viruses disperse, and travel around freely. As a result, they thrive in low humidity, and diseases such as RTIs are more common when relative humidity is low.
Susceptibility to respiratory diseases
Low humidity and low temperatures result in more susceptibility to catching respiratory diseases, colds, and many other respiratory tract infections like sinusitis, otitis, bronchitis, and pneumonia. This is because low humidity will result in drying out the airways.
Dry Hair and Dry Skin
When the air has low humidity, skin, and hair do not retain or get enough moisture. As a result, the skin will flake resulting in skin irritation and itching and can worsen skin conditions like eczema and psoriasis. Whereas hair will become more dry, frizzy, dull, and will break more often.
Influenza
Low relative humidity results in chances of spreading influenza. Low humidity further reduces the ability of cilia (hair-like structures in the airway cells) in removing viruses such as Covid 19 and preventing damage done to the lungs due to such viruses.
Decreased performance
Even minor variations in relative humidity and temperature can create measurable changes in your abilities to concentrate or accomplish tasks, especially in places like schools and offices where concentration is extremely important.