Do you ever wake up in the middle of the night with an attack of hay fever or pollen asthma? And do you ever wonder how this can happen? The explanation is that warm air, rising up from ground level on a summer’s day, takes pollen with it high into the earth’s atmosphere. When the air cools down after sunset, this pollen slowly descends again — an invisible “pollen shower.”
In the countryside, it falls quite quickly, reaching ground level between 8 and 10 p.m., but in the city, hot pavements and buildings keep upward air currents going, and pollen stays aloft for longer. Most pollen lands on the city between about midnight and 2 a.m. That’s why you wake up sneezing or wheezing — especially if you sleep with the windows open.
Understanding facts like these about pollen can help you to substantially reduce exposure. Pollen is by far the most difficult allergen to avoid, but don’t believe the defeatists who say, “You can’t do anything about pollen.”
Pollen Counts and Forecasts
Pollen counts are based on the amounts of pollen collected at specific sites earlier in the day, or on the previous day.
Forecasts for the coming day are really just informed guesswork, based on the present pollen count, the time of year, the temperature and rainfall over the last few days, and the weather forecast for the next day. At best, pollen forecasts are only as good as the weather forecast.
However, pollen forecasts can be useful in deciding when to start taking antihistamines for hay fever or when to increase your asthma-prevention drugs. The starting times of the different pollen seasons are now predicted quite accurately.
Avoiding Pollen Outdoors
One thing that can really help is to turn on the air conditioning in your car. In a non-air-conditioned car, closing the windows (and perhaps fitting a filter to the air intake) helps a lot.
A good exercise mask will help keep out pollen grains and fragments during peak pollen times. Wearing a scarf over the mouth and nose will also give some protection.
Another option to is smear a little Vaseline just inside each nostril and breathe through your nose only. Much of the pollen coming into your nose will stick to the Vaseline.
Timing Is Everything
Pollen release occurs at different times of day for different plants. Ragweed starts very early, releasing pollen between sunrise and 9 a.m., although damp conditions can delay release until as late as 2 p.m. Grasses release pollen from about 7:30 a.m. onward, but if the ground is damp, the release will be delayed until the moisture is evaporated. A few species of grass wait until the afternoon, so there will be some pollen entering the air all day. If you get up at 6 a.m. for a walk or run, you can be home safely by 7:30. Alternatively, go out in the early evening, after grasses have finished releasing pollen, and before the evening “pollen shower.” Birch is an afternoon pollen: Release peaks between noon and 6 p.m. Unfortunately, there is no specific information at present about pollen-release patterns in other plants.
In general, all types of plants favor warm, sunny days for releasing pollen, and they tend not to do it during rainy weather. Rain also washes residual pollen out of the air. On cloudy days there is a buildup of pollen in the flowers, so a massive release of pollen occurs on the next day of good weather.
Avoiding Pollen Indoors
Pollen grains have one huge point in their favor: Compared to other allergenic particles, they are big and heavy. This means that they settle more quickly from the air. In a room with 10-foot-high ceilings, all the pollen will settle within four minutes, as long as the air is completely still. In other words, if you close all the doors and windows, block off any drafts and sit fairly still, within four minutes you will be breathing pollen-free air.
This does not mean that all your symptoms will instantly vanish, because a “late-phase reaction” can go on for up to 24 hours. But you should feel better, and by not starting a new cycle of allergic reaction, you are improving your prospects for the next day. Escaping from pollen for a few hours every day should produce a general improvement in the long run, with your nose and airways becoming less inflamed.
Unfortunately, some plants, like ryegrass and ragweed, produce allergenic fragments much smaller than pollen grains. These tiny particles take up to 6 hours to settle.
Some plants even produce “volatiles” — airborne chemicals that provoke symptoms. Birch trees release volatiles from their buds in early spring, weeks before the pollen itself is released, and they affect a great many people, including some who are not allergic to birch pollen. Volatiles can only be removed by masks and air filters that contain an activated carbon filter.
To cut down on the amount of pollen you inhale at home:
- Dry all your laundry indoors during the pollen season, to stop it from collecting pollen.
- Pets bring in pollen on their fur, so keep them outdoors during the pollen season, and avoid stroking them. Brushing them thoroughly before they come in is another option, but obviously the allergic individual should not do this.
- Close the windows, especially at times when the offending pollen is being released, and during the evening or nighttime “pollen shower.”
- Change your clothes when you arrive home, since they will be coated with pollen, and wash or rinse your hair. Keep some clothes for indoor use only.
- Aim for still air (no drafts, no fans, and no vigorous movement) in the rooms where the allergic individual works, sits, or sleeps. Air currents stir up pollen from the floor and furnishings. (No drafts mean poor ventilation, of course, which is acceptable during the pollen season — but ventilate again afterward, to avoid encouraging molds and dust mites.)
- If tranquil air is an impossibility, consider getting a high-quality air filter, or air conditioning. Alternatively, wet-dust and vacuum every day using a vacuum cleaner that keeps allergen particles in — to reduce the amount of pollen residue. People who are very sensitive may need to do this as well as having an air filter.
- Cover your armchair and bed with a sheet by day. In the evening, fold the sheet up very gently and wash it. This removes the layer of pollen that accumulates during the day. If studying, cover your desk and books when you are not working.
Places to Go, Places to Avoid
- For the grass-sensitive, mown grass is usually fine (it won’t flower), although some people react to skin contact with grass. However, pollen that has settled on the grass may be stirred up while the grass is actually being mown. Unmown grass does not flower and will cause symptoms. Wheat, barley, oats, and corn, although they are grasses, rarely cause problems. Rye and sugarcane do release pollen, and may affect some people.
- The levels of most pollens do not differ much between town and country. In fact, the upper floors of a high-rise building (with the air conditioning off) may be one of the worst places, because of pollen rising on warm air currents.
- The seashore is often pollen-free thanks to onshore breezes. Mountain peaks and ridges are also good, but deep mountain valleys can be pollen traps.
- Places that often suffer from “inversions” (air trapped at ground level) can have very high levels of pollen.
See also: 6 Cities to Avoid This Allergy Season