Updates from Environmental Experts

What is Pollen? It’s Time to Talk about the Birds & the Bees!

Dr Gabriela Adler Katz

Many of us will be at risk from allergic symptoms when the pollen count is high this fall. But what exactly is behind the common seasonal allergy symptoms of itchy, watery eyes and sneezing? What is pollen?

Pollen's Role in Creating Baby Plants

Pollen grains are scientifically known as ‘microgametophytes’ of seed plants and are responsible for producing male gametes - i.e. sperm cells. The granules find their way to the female parts (female ‘stigma’) of the same plants, eventually resulting in fertilization. 



In other words, pollination is the natural way for plants to create offspring for the next generation. The seeds contained in pollen grains contain the genetic code required to produce a new plant.

In this interesting article, the Guardian explores whether or not ‘botanical sexism’ could be partly to blame for the high pollen counts in some cities (!)

What Does Pollen Look Like?

weather and pollen

To the naked eye, pollen is a fine and powdery yellow substance. However, an individual grain can usually only be observed with a microscope because the size is so small - (it’s in the range of a single human hair strand). 

How Does Pollen Move? Is it Alive?

Pollen typically gets moved around by insects, wind, and water. 

For seasonal allergy, we particularly care about grains that move with the wind because they travel in large amounts in an untargeted way.

Plants can release billions of grains at once time - all nature’s method of ensuring they reach female plants.

 'Asthma Thunderstorms' & Seasonal Allergy


You might assume pollen levels will drop after it has rained, but this doesn’t always happen due to a process called ‘osmotic shock’.

One leading theory of Thunderstorm Asthma is that particular types of pollen grains can rupture and shed much finer, highly allergenic granules.

Key Takeaways

The weather really matters when it comes to predicting pollen allergy. In particular, dry and windy weather provide the ideal conditions for pollen to be carried as the grains are so small and light. 

This means the best we can all do is to closely monitor the live and forecast pollen conditions at the street-level, then take proactive action (i.e. allergy medicine as advised by treatment providers). 

Are Allergy Seasons Getting Harder to Predict?

There’s no single definition for when ‘pollen season’ starts or ends, because the pollen count where you are depends upon your exact location and the changing conditions there. 

However, climate change is making things even more complicated. We'll be discussing this in more detail in this upcoming webinar. Sign up for free below!

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