Allergy sufferers, beware: rain can increase pollen load
Normally, it is expected that Pollen will be washed away by rain, which should alleviate problems caused by hay fever. New research findings in the journal "Environmental Science & Technology Letters" however, spring rains may cause more Allergy problems than it eliminates.
Measurements by researchers at the University of Iowa showed that the Pollen falls in the air due to rain, as expected. The all-clear for Allergy sufferers is not given, however, since fragments of Pollen in the air when it rains significantly. And significant amounts of 2.5 to 11 hours, remained there also after the rain, long – the stronger the precipitation, the longer. The highest number of pollen fragments, the scientists found during a storm.
They conclude from the results that people who are sensitive to Pollen should be careful, because you can not assume that the Pollen counts after a rainfall is low. The chemist Elizabeth Stone advises ":;People who are sensitive to Pollen should avoid it, in the rain, especially thunderstorms, and to go for a few hours then out into the open."
Already in the 1990s, it was discovered that Pollen, some of which – for example, birch pollen – too big to be Inhaled, at high humidity, the Burst tend to be, and in smaller pieces. This can happen with Pollen, which is the layer of clouds reach. As the fragments you get with the rain drops and winds back up to the surface.