Foehn and other Ill Winds
Police car sirens whine through city streets. Officers are busy attending unusually high numbers of car accidents, rowdy crowd behavior, domestic violence and suicides. Hospitals overflow and the undertakers count the cash. Long-term residents know what is driving everybody crazy – the hot and dry wind that is blowing down the mountain range or out of arid regions. They call it the föhn in Central Europe, chinook and Santa Ana in North America, sharav in Israel, and a northerly, westerly or easterly in Australia. Every country has its own name for the ill winds.
What makes these winds so unbearable? Meteorologists and medical scientists of Alpine countries studied these winds for many years and confirmed a link between increases in accident, crime and suicide rates and the onset of the föhn. The chinook in the Rocky Mountains takes the blame for migraine and the sharav in Israel is said to cause weather sensitivity.
Effect on health and wellbeing
While there is enough statistical evidence to prove a relationship between the ill winds and wellbeing, scientists concentrate their research effort on specific elements of the winds. I believe, it is most likely a combination of all the following four factors:
- The winds are generally very dry. A mountain wind loses most of its moisture in the rain on its windward side, while the humidity in desert winds can be almost non-existent. The air dries the mucus membranes in the airways and sinuses. Then airborne germs, dust and pollen can easily get past the dry mucus and cause inflammation, irritation or an allergic reaction. The dry winds may also act as asthma trigger, and could cause migraine and sinus headaches.
- The temperature rises with the onset of the winds. In winter, springtime temperatures arrive within a few hours and in summer the mercury reaches heat wave levels. The short-term rises in temperature may cause springtime lethargy symptoms and heat-related body reactions, as discussed in chapter Heat.
- The winds are strong and often blow for weeks, sometimes months – enough to get on anyone’s nerves. Buffeting by winds causes rapid fluctuations in air pressure, thus triggering weather sensitivity.
- The friction between the land’s surface and the wind dislodges electrons from airborne particles, so that the mountain and desert winds contain a high proportion of positive ions. Respiratory problems, headache, depression and exhaustion are linked to positive ions.
Dry air and your health
In autumn and winter most weather fronts come from the ocean and a stiff, cold and humid breeze hits the shores. When it has to cross a mountain range, though, it loses much of its moisture and warms when it descends on the other side. People living on the lee side of the ranges often experience unseasonally mild temperatures and low humidity levels. The infamous Canterbury Nor’wester of the New Zealand South Island and the Chinook in the US Rocky Mountains are typical examples of ill winds that take the blame for many aches and pains and for feeling unwell. During the heating season, we are likely to further lower the humidity levels indoors.
Dry air can have a profound effect on someone’s health and wellbeing. Some of the negative effects are:
Infectious diseases and allergies
Like the old-fashioned sticky ribbon catches annoying insects, the mucous lining of nose, throat and airways catches invading bacteria, viruses and allergens. It is, therefore, the first line of defence against dangerous organisms. We sneeze or cough to get rid of them. However, dry mucus membranes allow airborne particles to easily get past this defence mechanism and may cause inflammation, irritation or an allergic reaction. In addition, bacteria and viruses find it easier to enter the bloodstream and trigger diseases.
Nosebleed (epistaxis) occurs frequently during winter in dry indoor air. The crusts of the dried mucus membrane can easily damage the tiny blood vessels when you can’t resist the urge to rub, blow, or pick your nose.
Headaches and migraine
There is enough statistical evidence to link ill winds to many negative health effects. For example, the chinook in the Rocky Mountains takes the blame for migraine and the sharav in Israel is said to cause weather sensitivity. Despite all the research, the mechanism that triggers the negative effects is still not well understood.
A better-known factor is the low humidity of these ill winds. With the entrance to your sinuses sometimes blocked by dry crusts or gooey mucus, excess mucus in the sinuses can’t drain and may trigger a sinusitis-related headache.
Dry skin and eyes
Dry skin and dry eyes are annoying conditions that occur more often during the heating season. Dry air may cause cracking, scaling or itching of the skin and could dry the moist outer layer of the eyes. Applying some moisturizer to the skin and medicated drops to the eyes, or increasing the humidity level, usually solves the problem.
The next time you get zapped by static electricity when exiting your car or touching a door handle, remember this explanation: the air is most likely very dry and doesn’t conduct well. Static electricity builds up in your body and discharges to a better conductor such as the door handle. The electric charge may act on your nervous system and could cause irritation.