Those of you reading this blog are aware of the updated website for the Alabama Allergy and Asthma Center (AAAC). One of the updates to the site is a posting of the most current pollen count from the National Allergy Bureau (NAB) certified collection station located on the Birmingham-Southern College campus. This posting provides information regarding the levels of tree, weed, and grass pollens in the Birmingham area as reported to the National Allergy Bureau. So what does it mean when the pollen count is high, or moderate, or low?
How are Pollen and Mold Spores Counted?
Pollen and mold spore counts are reported to the NAB as numbers of pollen grains or spores per cubic meter of air. The data sent to NAB contain the numbers of pollen grains or mold spores present in the air on that day for the specific plants and fungi listed on the NAB allergen report from the BSC/AAAC station. A sample allergen report submitted to NAB for March 20, 2015 is shown at the end of this blog. These data are then used to determine the levels of pollen and mold spores using the NAB scale that is shown below.
What do the Pollen Levels Mean?
The concentrations of pollen or mold spores are translated into levels based upon statistics from all certified counting stations across the nation. These levels are based on the following:
– Low levels are concentrations that are less than the median or 50th percentile (i.e. half of the counts were below the median)
– Moderate levels are concentrations that fall between the 50th and 75th percentile
– High levels fall between the 75th and 99th percentile
– Very high levels are above the 99th percentile (99% of the counts are below this level)
(Above information taken from American Academy of Allergy Asthma & Immunology (AAAAI) website—“Reading the Charts”)
The levels shown in the table are based on measurements of numbers of pollen grains and mold spores in the air and not on the health effects these
allergens have on people.
Thus a high level of tree pollen does not mean that there is necessarily a high level of significant health effects. It does mean that the count that day of tree pollen is considerably higher than the majority of days and that if you are sensitive to tree pollen(s), then you should avoid outside activities and be sure to use appropriate medications as prescribed by your allergist to reduce the likelihood of developing allergy symptoms.
The greater the number of pollen grains in the air, which triggers your allergy, the more precautions you should take. Keep up with the pollen levels and help reduce you incidence of allergic rhinitis/conjunctivitis.
H. Wayne Shew, Ph.D.
NAB certified counter
BSC/AAAC Collection Station—Birmingham, Alabama
To find out what the pollen levels are in your area, visit our Pollen Counter on our homepage.