Allergen Levels

More than 67 million Americans suffer from some form of allergies, most commonly from pollen from trees, grass and weeds. Another common allergen is mold spores. The levels of these substances are measured as allergen levels and released to the public.

Collecting Readings

• The National Allergy Bureau does official allergy reporting by collecting readings from various counting stations. The workers at these stations are often volunteers. You can join as a counter through the National Allergy Bureau's website (see the Reference section for a link).

Reporting

• The allergen levels of an area are measured by amount per cubic meter reported by counting stations. These are averaged into counts that are divided among the types of allergens (grass, weed, trees and mold) and are reported to news stations, newspapers and other media outlets for use in weather reports.

Considerations

• Alergen levels are categorized on a scale ranging from absent to very high. Trees that produce large amounts of pollen include birch, alder, cedar, hazel, chestnut, willow, plane, olive and hornbeam. Grasses include rye grass and timothy, while weeds include ragweed, nettle, mugwort, fat hen and sorrel.