University of Innsbruck

FAQ - Interesting facts about pollen in Tyrol

Why do we have hay fever at all? When is the exposure particularly high? And where exactly does the Tyrol Pollen Warning Service collect its samples?

We have summarised the answers to these and other questions here: 

Bless you! If your eyes and palate itch and your nose runs during the warmer months of the year, this may be due to "hay fever". A pollen allergy is a reaction of the immune system to pollen in the air. Pollen corresponds to the yellow dust produced by grasses, cereal, trees or herbs. To reproduce, these plants rely on the wind to spread the pollen. When the pollen hits the mucous membranes of the nose or eyes, the body's defence system reacts with a local inflammatory reaction, even if the pollen itself is not harmful. Depending on the severity, a pollen allergy can interfere with everyday life and cause long-term consequences such as asthma. For more information and treatment options, we recommend that you see an allergy clinic or specialist.

Between 40 and 49 different types of pollen land in our seven pollen traps every year. The following types are particularly relevant for allergy sufferers and are taken into account in the pollen report and in our annual report: 

Alder pollen (Alnus): moderate to high allergenicity and frequent cross-reactions with pollen from hazel and birch.

Hazel pollen (Corylus): moderate allergenicity and frequent cross-reactions to hazelnut (food allergy) and pollen from birch, alder and hornbeam.

Hornbeam pollen (Carpinus): low allergenicity and possible cross-reactions with pollen from birch, alder and hazel, especially in gardens and parks.

  • Hop-hornbeam pollen (Ostrya): cross-reaction in birch pollen allergy sufferers, especially in gardens and parks.
  • Ash pollen (Fraxinus): Cross-reaction with pollen from plants related to olive trees.
  • Birch pollen (Betula): high allergenicity.
  • Grass pollen (Poaceae): high allergenicity.
  • Plantain pollen (Plantago): moderate allergenicity, which may occur in people allergic to grass pollen.
  • Mugwort pollen (Artemisia): high allergenicity.
  • Ragweed pollen (Ambrosia): invasive plant with high allergenicity, not yet highly relevant in Tyrol.

In 2021 we were able to measure the first alder and hazel pollen at the beginning of February. Ash and birch usually start to blossom at the beginning of March, and hornbeam and hop-hornbeam pollen join them at the end of March. Exposure to grass pollen is usually to be expected from mid-April. Mugwort and ragweed usually cause discomfort in August and September.

Yes, as shown, for example, by our analysis of a long data series covering the period 1980 to 2001, which showed that the peak of the flowering season is clearly moving forward by several days. We expect this trend to continue; the progressive warming of the climate will also have an influence on the vegetation periods of plants in Tyrol.

Ragweed (Ambrosia artemisiifolia) is a neophyte, i.e. an immigrant or introduced plant species. Its pollen is a heavy burden for allergy sufferers. Analyses have shown that ragweed has been growing in the Alpine region for about 50 to 100 years. The allergy risk of ragweed is considered to be particularly high and unfortunately this risk is even higher in combination with air pollution. This means that nitrogen oxides from car exhaust intensify the aggressive character of ragweed pollen. Between Rietz and Haiming ragweed is already growing extensively and we assume that its area of spread will continue to increase in the next few years. The main flowering time of ragweed is in August, which means that the allergy season for sufferers extends into late summer.