Dry, unrefreshing air is more than a nuisance – it can cause significant health problems.
Poor humidity levels in the air dehydrate the skin and mucous membranes, leading to feelings of dryness and discomfort. If you notice dry eyes and lips after waking up or a scratchy throat every morning, the air you’re breathing may be too dry.
What causes dry air?
Cold air retains less moisture than warm air. During the cold winter months, the absolute humidity outdoors doesn’t tend to change very much (the total amount of moisture in the outside air remains within normal range), but the relative humidity inside our homes will often drop significantly.
The warm air inside your home leaks out through the windows, doors, and other openings, carrying its moisture with it. While your heater works hard to increase the temperature, it doesn’t add any moisture back into your home.
The resulting dry air will then suck the moisture out of anywhere it can find it, including your skin, lips, eyes, and the mucous membranes inside your nose and bronchial tubes.
Risks of Dry Air
When your breathing tubes become dehydrated, they become more vulnerable to irritations. This can worsen symptoms of asthma, bronchitis, sinusitis, and other respiratory illnesses. Nose bleeds are also more common in low humidity environments.
Your eyes also can lose their moisture and become easily irritated.
As the air pulls moisture out of your skin, you may notice your skin feels tight, itchy, and flaky. Low temperatures and low humidity lead to a general decrease in skin barrier function and an increased susceptibility to irritants and allergens. Conditions such as eczema and atopic dermatitis can worsen. This is why it’s especially important to use moisturizing lotions during these months.
Dry air may also contribute to increasing the spread of colds and the flu, including SARS-CoV-2 (COVID-19). There are many explanations for this.
Our dry noses are less able to clear away invaders. Dehydration and cold temperatures weaken our immune system, and tissue repair mechanisms are slowed. Exhaled bioaerosols evaporate quickly in low humidity environments, meaning the dangerous droplets remain in the air for longer. SARS-CoV-2 also appears to be less stable at high temperatures and high humidity, so the winter climate may tend to keep it alive for longer.
However, this is just one-factor influencing spread. Other active measures are also important for preventing further infections.
Humidify Your Home
When the air feels too dry, it’s time to use a humidifier.
A humidifier restores an appropriate humidity level and can be used throughout the home. You may even consider using one in your bedroom overnight, so you wake up to more comfortable morning air and healthier skin.
If you’re not sure how much humidity is in your home, many devices are available to help you determine the relative humidity. The EPA recommends keeping your home and workspaces between 30-50% humidity.