If you suffer with seasonal allergies you might think a spring rain is a good way to wash away that pesky pollen, but a new study reveals that’s not necessarily the case at all. University of Iowa researchers have found that tree pollen fragments remain in the air for two-and-a-half to as many as 11 hours after heavy rains, and that those granules can make their way deep into the lungs, potentially exacerbating allergies. Study author Elizabeth Stone says, “People who are sensitive to pollen in season should avoid going outdoors during rain events, especially thunderstorms, and for several hours afterward.” The issue is that pollen grains can be carried up into the cloud base by storm updrafts where the high humidity ruptures them, and then their fragments fall back down to Earth with the falling rain and the storm’s downdraft.
-EurekAlert