What Is A Pollen Count
If you have seasonal allergies, hay fever or rose
fever, you have probably been told by your allergist to keep an eye on your
pollen counts. You probably know what pollen is, but have you ever wondered who
counts the pollen, how it is counted and why it is counted? Why are pollen
counts important to people with allergies?
are the sperm cells of plants. They are usually coated with a hard surface. They
come in many shapes (although most are round) and sizes. Pollens are generally
yellow and waxy or white and light.
The waxy, yellow pollens are not usually the
culprits in seasonal or allergic rhinitis. These pollens are produced by plants
that depend on insects such as bees and wasps to provide pollination assistance.
The pollens are designed to stick to the insect legs and wings so they can be
transferred to the female plant (or portion of the plant). These pollens are not
generally included in the breakdown of pollen counts.
Pollens that are white and light are designed to
be blown by the air from one plant to the next. These pollens are the real
culprits. They are produced by trees in the spring, grasses in the summer, and
ragweeds in the fall. These are the misery causing pollens that are the reason
pollen is counted.
Pollen counts may be taken by weather observers, allergists or immunologists,
government agencies, or independent researchers and scientists. They are taken
using one of two methods, the Rotorod method or the Burkhard trap method.
In a Rotorod samples, two rods are coated with
silicon grease and are attached to a motor that spins them around in a fixed
circumference. Pollens in the air hit the rods and adhere to the silicon grease.
The pollen grains are then held in place until the test is complete. The rods do
not spin continually, but work on a cycle of 10% on then 90% off, and then 10%
on and so one. At the end of the test, the collector rods are removed and
stained to show pollens and are then inspected under a microscope. The number of
particles per cubic meter of air is calculated based on the volume of the air
sample. The pollens are also indentified by the type of plant at the same time.
In the Burkhard trap method, either a slide or
piece of tape is coated with a silicone adhesive material (like the Rotorod) and
then is slowly moved past air inlet. The substrate is then removed and stained
(like with the Rotorod method) and the pollens are identified and calculated
based on the volume of air and the length of exposure. In 1999, David Frenz
published a study in the Anal of Allergy Asthma and Immunology that showed that
there were only slight differences between the two methods. Either should be
considered accurate, even if the Rotorod is slightly better when the pollens are
greater than 10 microns and the Burkhard spore trap method is slightly better is
the pollens are less than 10 microns. Either way the pollen is counted, it will
provide reliable information.
So why do you need this information? Knowing the amount and types of
pollens in the air can help you avoid exposure and is an important of your
allergy control program. By checking pollen counts, you will know if it is a
good day for a picnic or maybe a better day for a movie or trip to the museum.
If you exercise, you might want to take pollen counts into consideration and
schedule your routine accordingly. Generally, pollen counts will be higher in
the morning and on windy days. Pollen counts are lowest just after a rainfall
and in the middle of the day.
If you cannot plan around high pollen counts, you can protect yourself when
outside. Wear a dust or pollen mask that will trap particles as small as 30
microns. This will grab most pollens. When you come inside, go directly to the
bathroom and shower, wash your hair and change clothes. The bathroom is probably
the room in your house with the most hard surfaces. Since pollens stick to our
skin, hair, and clothing removing your clothes will cause the pollens to fall
off. By letting them fall to a hard surface you make it easier to clean them up.
If you cannot wash your hair then brush it thoroughly in the bathroom to remove
the pollen. Take your pollen-filled clothes directly to the hamper. Some people
like to use the Allergen Wash to wash away pollens, but any good soap will do
You can find your pollen counts at websites such as
Pollen.Com or most any of the weather
websites like WeatherUnderground.Com.
Pollen counts are already starting to rise in the South. When pollen season gets
to your area, be informed and be prepared.