As a ritual, each spring summer and fall, tiny particles known as pollen are released from trees, grasses and weeds. Pollen is transported by air currents
and enters human noses and throats, triggering an allergic reaction named allergic rhinitis, also known as Pollen Allergy. According to the National Institute of Allergies and Infectious Diseases, a branch of the National Institute of Health, approximately 35 million Americans complain from upper respiratory symptoms related to pollen.
Not everybody is allergic to pollen. Scientists believe that some people inherit a tendency to be allergic and respond with a specific immunological reaction. In an allergic reaction, the body's immune system generates a type of antibody called immunoglobulin IgE. The antibody developed is specific for each type of pollen. ie: ragweed, oak, sagebrush, etc. Each plant has a pollenation period that is more or less the same from year to year. The length of the pollenation period is dependent on the relative length of night and day, and the geographical location. More pollen grows in the northern latitudes of North America in this time period.
Pollen count is a measure of how much pollen is in the air in a certain area at a specific time. It is expressed in grains of pollen per square meter of air collected over 24 hours. Pollen counts tend to be highest early in the morning on warm, breezy days and lowest during chilly, wet periods. Weather conditions during pollenation can effect the amount of pollen produced and its distribution.
Thunderstorms can precipitate respiratory difficulties. Initially, windy conditions that usually precede storms stir dust, mold, pollen and this may activate allergies. Later on, heavy rains tend to break pollen into small particles, allowing the smaller pieces to be inhaled deeper into the lungs and causing more significant symptoms. source (Ref: Stump B. "Under the Weather? Men's Health 1999; 14(3) 124-4)
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