What Is a Pollen Count?

By Stanley Goff

Every spring, millions of people anxiously watch the news for something called the pollen count. These people experience respiratory problems from allergies to pollen, the ultra-fine powder of male gametes that plants release to reproduce. If the pollen count is high, these “hay fever” sufferers know they will have to carry along their allergy medications to get through the day.

Walter Jinotti

In the early 1980s, a biomedical engineer and inventor named Walter Jinotti developed a device for measuring the amount of pollen in the ambient air. Jinotti himself was motivated by his own struggle with pollen allergies, which he described as “little men running around in my head, hitting me with hammers.” By 1987, Jinotti has refined his device to the point that it could get a “pollen count,” his term, within 20 minutes. He began broadcasting these pollen counts on local radio stations, and quickly gained a wide audience.

Pollen Count Categories

Pollen counts are measured as grains of pollen per cubic meter of air. A pollen count of 0 to 30 grains per cubic meter is considered “low.” Counts between 31 and 60 are called “moderate.” Enumerations between 61 and 120 are called “high,” and above 120 is considered “extremely high.” Refinements in assessment have since given observers the ability to identify levels of individual species of pollen by grains per cubic meter, as well as the ability to identify airborne molds.

Pollen Count Measurement

The device for measuring the pollen count is called a Rotorod system. Air is allowed into a container, whereupon it is closed off and a rod rotates as it moves around the container for a set period of time. The rod is coated in silicone grease, to which the airborne particles adhere. The substance is then stained and observed under a microscope. Particles per microscopic field are extrapolated, using a tested formula, to determine an approximate grains per cubic meter.

Using the Pollen Count

Pollen counts cannot predict pollen concentrations. Pollen counts are empirical observations of what has already taken place. Allergy sufferers need to take the pollen measurement into account, then study the weather forecast. The worst conditions for those with pollen allergies are warm, dry and windy. Pollen, like any dust, is lighter when dry and more likely to be airborne. Damp or rainy days are good news for those with hay fever, at least with regard to their allergies.

© Demand Media 2011