There is no such sense of a pollen "rate," but there is of a pollen count. Which means the average pollen grains in a cubic meter!

?

The Pop Singer's Fear of the Pollen Count was created on 1999-08-09.

Pollen count is the measurement of the number of grains of pollen in a cubic meter of air. The higher the number, the more people will suffer if they are allergic to a particular pollen. Usually, the counts are announced for specific plants such as grass, ash or olive. These are tailored to what is usually a common plant in the area being measured.

?