Thursday, March 18, 2010

Pollen Counts and Forecasts Explained

Spring is inevitably on its way, which means allergy season isn’t far behind. Fortunately for seasonal allergy sufferers, the awesomeness of science helps to provide some relief.

n counts enable pollen forecasters to provide allergy sufferers an opportunity to mitigate their symptoms. A pollen count is a measurement of how much pollen is in the air. This count represents the concentration of all the pollen (or of one particular type, like ragweed) in the air in a certain area at a specific time. It is expressed in grains of pollen per cubic meter over a 24 hour period.

To do a pollen count, a pollen sample is taken using an air-sampling device. These s
amplers collect particles from the air onto a transparent, sticky surface. The sample is then examined under a microscope, where the pollen grains are counted and identified. Since pollen travels long distances through the air, this count is relevant to a large area, and a count from one sampling site is typically used as data for an entire city.

A pollen forecast is a prediction of what the pollen levels will be in the future, like a weather forecast. Pollen forecasting often has greater value for allergy suffers than a pollen count, because they can use this information to plan their day, including whether or not to take medication.

Pollen forecasting methods consider natural events, besides the recent pollen counts, that will affect future pollen levels. We consider historical pollen counts (which provide predominant pollen and seasonal trend information for a certain area) temperatures, precipitation, and weather forecasts.

Pollen forecasts are geographically specific down to the city. For the pollen forecast in your area, visit