After a string of warmer than normal days, the tree pollen is going up fast. In fact we got word Monday from the Marshfield Clinic-Wausau Center that tree pollen was measured at a level of over 300, which puts it in the high category. So if you have red, itchy eyes, sneezing, headache, runny nose, and fatigue…this could be your culprit. We will be passing on the pollen information throughout the growing season here on WAOW-TV. We know many of you are impacted by seasonal allergies so we want to help you as much as we can. The Marshfield Clinic-Wausau Center released a very informative press release on how they measure aeroallergens. Please take a few minutes to read through it. You may find it useful. One key point I saw was that the measurement they report each morning is actually an average for the past 24 hours.
Aeroallergen counting involves the measurement of specific allergens or allergen classes in the atmosphere. This is typically performed using volumetric measuring devices. Each device has a range of particle sizes which it counts most efficiently. Counts are reported in particles per cubic meter of air. This value represents the average over the counting period. It does not represent an instantaneous value. Thus 20 hours of high pollen exposure followed by 1 inch of rain in the last 4 hours will still produce a high pollen count for the day. The next 24 hour period will likely be affected though.
Factors which affect the pollen counts include most notably the life cycle of the plant being studied and the weather. Plants progress through the normal pollen producing seasons as follows:
Trees: Late March to early June. The beginning of the tree season is significantly affected by the weather and quite variable.
Grass: June-July, peaks the third-fourth week of June.
Weeds: August-September, peaks near the end of August, gone with frost.
Warm, dry, windy conditions tend to favor higher pollen counts. This tends to be especially true early in the season when it also aids in plant maturation. Favorable weather by itself cannot cause high counts though. An example would be as the normal pollen producing period is winding down, few pollen are being released. In contrast, even significant rain can be overcome by high pollen producing periods.
Pollen counting has been performed by the Marshfield Clinic and the Wausau Medical Center for many years. Following the merger of the two clinics in 1997, it was decided that pollen counting for the system would take place exclusively in Wausau. This service has been supported and managed by the Allergist of the Marshfield Clinic System and performed directly by trained lab technicians. A Rotorod sampler is currently utilized and positioned on the roof of the Marshfield Clinic-Wausau Center. It is very effective for counting pollen. This device is not as efficient for mold spores less than 10 microns and thus mold counts are not performed. Mold spore counting requires a significant increase in technical equipment and labor resources and thus is not routinely performed by most pollen counting stations.
We would be happy to discuss the workings of the Rotorod sampler in more detail if desired. A site visit could also be arranged with our lead lab technician (Ray).
I hope you have found this information useful. I think this service does help educate the public and certainly helps our patients as well as ourselves, the treating physicians.
Please do not hesitate to contact me if there are any questions.
Mark Huftel, M.D.
Marshfield Clinic-Wausau Center, 847-3430
Pollen Count Ranges
Low Moderate High Very High
Trees < 15 15-90 91-1500 > 1500
Grasses < 5 5-20 21-200 > 200
Weeds < 10 10-50 51-500 > 500
This post was written by Tony Schumacher on April 29, 2013