An average human sheds up to 1.5 grams of skin particles each day. In just one gram of dust, there can be upward of 1,000 mites.
Allergic Rhinitis: Mold Spores
As if pollens aren't enough, there are fungal spores, commonly known as mold spores, floating around in the air you breathe. Spores differ from pollen in how they reproduce, but they are spread the same way. As the season becomes warmer (summer to early fall), mold spores hit the air currents. Some mold spores prefer to ride the dry winds, while others need high humidity and condensation to get off the ground. Thankfully, only a few dozen out of the hundreds of molds trigger allergic reactions. Those that do, however, do it well, infiltrating the nose and lungs and triggering hay fever and asthma flare-ups.(Don't) Shake It Up
Mold spores love moisture and often grow on the ground or on decaying vegetation, so victims usually inhale them while "stirring things up" during activities such as mowing the lawn, raking leaves, and cleaning the basement. When you stir things up, molds become airborne. But molds (and pollens) can also enter your life through an open window, carried in with the breeze, which you then breathe.
Indoors, mold will set up housekeeping if you have the ideal environment for them to thrive and reproduce. Prime mold real estate includes dirty laundry hampers, old newspaper piles, carpeting, fireplace logs, houseplant soil, foam rubber mattresses and pillows, bathtubs, bathrooms, and dark, damp basements. Water leaks from pipes or windows speed the development of mold, especially if the water gets on carpeting. Humidifiers and vaporizers are also a major source of indoor mold. Need we mention that mold spores love traveling, too? Air-conditioning vents (home and car, alike) have the best seating.
If you are highly allergic to mold spores but not to pollens, moving to a drier, high-altitude area may help ease your allergies.