Commentary: Most of the top 50 cities in the Allergy Capitals lists are in the Southeastern U.S. The likely explanation is the highest pollen counts occur in the Southeastern U.S., because of the longer and warmer climate + greater vegetation which cause more allergies and so more medication use. These are two of three criteria used to determine the rankings. The table above can not be found in this format anywhere else on the internet.
I disagree with the 3 measurements used to determine their rankings of Allergy Capitals:
Separately, Greenville ranks about 20th in the spring and about 42nd in the fall fairly consistently.The pollen counts are higher in the spring than in the fall, as it is for most of the SE US.
12/13/11 My other objection to the list is: how are the pollen and mold counts determined? My office has been responsible for the pollen counts in Greenville since 2000. We don't publish mold counts, because we use a Rotorod sampler, which does not count mold spores accurately. Almost every site listed in the National Allergy Bureau's website uses the same sampler (private communication). I also know the NAB does not monitor 100 other pollen and mold counting stations. So where does the certified data come from? I happen to have lived in Dayton, OH and I know the pollen counts weren't as high as Greenville's. Perhaps the climate and vegetation has changed.