Thursday, May 23, 2013

Aeroallergens are Nothing to Sneeze At: Birmingham’s Only Pollen Counting Station

By: Heath Haggard and Dr. Wayne Shew
Birmingham’s only National Allergy Bureau (NAB) pollen collection station is located on the campus of Birmingham-Southern College, where it is run by Dr. Wayne Shew and sponsored by Dr. Weily Soong and the Alabama Allergy and Asthma Center.  The partnership between Birmingham-Southern and Alabama Allergy and Asthma began in 2007 when Dr. Soong contacted Dr. Shew to talk about the absence of a pollen station in Birmingham and the need for establishing such a station that would be located within thirty miles of the clinic’s practice.  Dr. Shewfirst began collecting pollen samples using a Rotorod collector, which was soon replaced with the installation of a Burkard Volumetric Spore Trap.  The pollen collecting station was certified as an NAB site in the summer of 2010, and since that time the station has maintained a consistent reporting of pollen counts to the National Allergy Bureau.  The station aids the Alabama Allergy and Asthma Center by providing pollen and mold spore counts which benefit the clinic’s patients, and also provides data useful for clinical research and senior research opportunities to students at Birmingham-Southern College.

The pollen samples used at the station to generate counts are collected using a Burkard Volumetric Spore Trap located on the roof of the Humanities building on the campus.  The Burkard spore trap collects airborne particles on microscope slides coated with Dow Corning high vacuum grease.  Air is pulled through a 2 x 14 mm opening and impacts the microscope slide at a constant volume of 10 liters/minute.  The air is sampled for a 24 hour period, the slide is removed, and the sample is mounted for microscopic examination in glycerin jelly containing fuschin stain.  Fuschin stain is selectively absorbed by the pollen grains, which appear pink when viewed under a microscope at 400x.  The Longitudinal Transverse Method, which involves counting the number of specific pollen grains present in a horizontal pass across the slide either one or two times, is used to count and identify the pollen grains present on the slide.  The number of counted pollen grains can be converted to number of grains per cubic meter of air using the following formula:

Pollen Grains/m3 of air= number of grains counted

Vair sampled               .

Volume of air sampled in the formula described above is calculated using the following formula:


Vair (m3) = Field Diameter (µm)

drum rotation rate   .

Pollen counts generated at the Birmingham station can be accessed through the Alabama Allergy and Asthma Center’s website,, or through the American Academy of Asthma and Immunology’s National Allergy Bureau,
This was written by Heath Haggard of Alabama Allergy & Asthma Center and there subsidiary Clinical Research Center of Alabama in conjunction with Dr. Wayne Shew at Birmingham Southern College.


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