Pollen season 2023: Severe early start with tolerable continuation

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- Medicine & Science

This year, the pollen count started about a month earlier than the long-term average; and with some force. Fortunately, birch and ash will not continue this trend. Allergy sufferers can expect a rather mild season, although the intensity of the impact cannot yet be predicted. The reason for this "up and down" is climate change, which confuses plants and has an impact on people with pollen allergies as well as asthma. Because: Global warming brings with it changes in weather conditions such as milder winters and more extreme weather events. Experts explained the background and consequences of this at today’s press conference held by the Austrian Pollen Warning Service at MedUni Vienna and the IGAV (Interest Group for Allergen Prevention) information platform and presented the new "Asthma Weather" and "Thunderstorm Warning" services in the pollen app.

Increasingly, pollen allergy sufferers are being troubled by global warming. "Last winter was one of the mildest winters in recent decades," says Harald Seidl from GeoSphere Austria (formerly ZAMG). "In the low regions, this winter was recorded as the sixth warmest in the 256-year history of measurements." That had an impact on plant flowering. The warm weather was ideal for plants to release their pollen to the wind particularly early. "In January, around a month earlier than the long-term average, hazel and alder trees began to flower in the east," explains Uwe E. Berger, Head of the Austrian Pollen Warning Service at MedUni Vienna. This has caught many allergy sufferers off guard. "However, it was not only the early appearance of the first symptoms that was remarkable, but also their intensity. Allergy sufferers reacted more strongly than average to small amounts of pollen in the air," says Berger.

Birch and ash, on the other hand, have taken longer this year. The cool and changeable weather of the last few weeks has confused the plants and delayed the start of the season. Birches need a constant temperature above 10 degrees to flower. Berger: "This condition has now been reached, which means that the popular avenue tree - like the ash - is ready to flower throughout Austria. However, it cannot be predicted at the present time whether the severity of symptoms will also be lower despite the lower pollen load."

Stress for nature and humans
What is certain, however, is that numerous allergens "are being produced more when plants suffer from stress," emphasises Barbara Bohle, head of the Institute for Pathophysiology and Allergy Research at the Medical University of Vienna. -For example, this is the case with heat, drought, food competition as well as increased exposure to environmental pollutants such as ozone, sulphur and nitrogen oxides." Several studies have shown that stressed birch trees produce higher amounts of their main allergen Bet v 1 and that birch pollen from trees exposed to higher concentrations of nitrogen oxides and ozone trigger more severe allergic reactions in allergy sufferers. "In addition, air pollutants have a direct harmful effect on the airways of allergy sufferers and thus contribute to the intensification of allergic symptoms," adds Barbara Bohle.

Climatic changes not only have an impact on plants, but also directly on humans; especially on those with persistent or recurring illnesses. "The weather itself does not make people ill, but it can influence the course and intensity of illnesses," explains biologist Holger Westermann, editor-in-chief of menschenswetter.de and menschenswetter.at, a service platform for people who are weather-sensitive. "The more dramatic the physiological stress for the organism, the greater this effect - i.e. if the weather change is abrupt and far-reaching or when a manifest pre-existing illness is particularly sensitising."

Thunderstorms can trigger asthma attacks
For people with pollen allergies and asthma, the influence of the weather is an issue in many aspects. Very high temperatures, in particular, can become a problem for them. In times of persistent heat - especially in big cities - the air we breathe is polluted by ozone and fine dust, which can trigger asthma attacks. If there is also a lack of cooling off at night, the quality of sleep deteriorates, the organism cannot recover sufficiently and becomes more vulnerable to pollen. Finally, when a - supposedly relieving - summer thunderstorm hits, pollen swells, bursts and releases large amounts of allergens which, in turn, pose a high risk for asthma attacks. "Knowing about risk factors and avoiding them as well as adhering to allergy and asthma treatment is therefore crucial to prevent thunderstorm-induced asthma," appeals lung specialist Felix Wantke, head of the Floridsdorf Allergy Centre in Vienna (FAZ).

Weather extremes are increasing
Everything that is bad for a pollen allergy sufferer, who sometimes also suffers from asthma, comes together during a thunderstorm: a rapid drop in temperature, high humidity, a sudden increase in pollen concentration and ozone pollution. Thunderstorm asthma is still a rare occurrence. Due to climate change, future events will probably become more frequent and unpredictable.1 The reason: "The warmer the air, the more moisture it can absorb and transport to high altitudes. The interaction of cloud droplets with different aggregate states, such as sleet or hail, creates atmospheric electricity which is discharged in the form of lightning. The simple formula: The greater the heat, the more violent the thunderstorms can become," explains weather expert Seidl.

New in the Pollen-App: -Asthma weather- & -Thunderstorm warning-
Based on the knowledge that thunderstorms can trigger and drastically aggravate asthmatic symptoms, the pollen app of the Austrian Pollen Warning Service has been further developed and supplemented with new services on the occasion of its 10th anniversary. "With the ’Asthma Weather’, which was developed in cooperation with www.menschenswetter.at, users can obtain information on five levels as to whether the weather conditions of the day can lead to increased or decreased asthma symptoms," describes Markus Berger, medical staff member of the Austrian Pollen Warning Service. "The ’thunderstorm warning’ indicates when thunderstorms are to be expected and whether the ozone levels will rise in the area. In addition, there is a recommendation to stay indoors and to get medication in time."

The app is available for free download for iOS and Android at www.pollenwarndienst.at and the app stores and also works beyond Austria’s borders.

Link tips:
www.pollenwarndienst.at - Individual pollen exposure, download pollen app, online self-test etc.
www.pollenallergie.at -Service for physicians
www.allergenvermeidung.org - Information platform for allergy sufferers