With all the different pollens in the world, why is ragweed pollen so important in testing filters?
Ragweed pollen is an airborne pollen, which means it primarily uses air currents as its method of distribution. Eighty percent of pollens are biotic which means they use other animals to move the pollen. Bees and bats and even birds are essential for the vast majority of plant life pollination. When testing an air filter, then, the focus is on airborne pollen.
Ragweed pollen is extremely light and extremely small. The average size of air borne pollen particulate is about 25 microns, while the average size of Ragweed pollen is 17 microns. When ragweed season comes, the pollen produced is practically everywhere. Ragweed pollen has been found over 15000 feet in altitude and four hundred miles out to sea. (1)
Allergic reactions to ragweed pollen are very common, affecting millions of people. This is not to say that ragweed is the only pollen that triggers allergic reactions, but ragweed is often responsible both as a primary source and also as a source of cross-reactivity.
Finally Ragweed pollen is commercially available as a standard for testing labs. Standards are essential in scientific testing, so that filter efficiency can be tested and those tests can be replicated.
Ragweed pollen’s use as a standard reflects its widespread presence, the difficulty its small size presents, and its culpability in the suffering of so many people.