High Exposure in Warm Weather
When temperatures reach approximately 12 to 15 degrees Celsius, birch releases its highly allergenic pollen. "If the coming days and weeks are sunny and warm, high birch pollen exposure is expected across Switzerland," says Roxane Guillod, Head of Professional Services at aha! Swiss Allergy Centre.
Indications of Higher Exposure This Year
Additionally, exposure might be especially high this year. In many places, particularly bloom-rich birches are currently observable. Dr. Benoît Crouzy, responsible for SwissPollen at MeteoSwiss, notes: "In recent years, development varied by region. A clear biennial rhythm has not been distinctly confirmed recently. Exposure was particularly high in the western Central Plateau last year." Although the start of blooming on the northern side of the Alps is within the long-term average this year, "over several decades, a trend towards earlier and sometimes more intense pollen seasons has been seen in Switzerland," says Crouzy. A factsheet from SCNAT confirms this trend: pollen seasons tend to start earlier, and tree pollen exposure has increased over the past 30 years. Ash pollen is also already in the air. How intense the pollen season actually becomes heavily depends on further weather developments.
Birch Pollen Particularly Burdensome
Birch pollen is among the strongest triggers of hay fever. "Just around 70 birch pollen grains per cubic meter of air can cause allergic symptoms such as itchy eyes, sneezing, or a runny nose," says Roxane Guillod. As birch pollen is very small, it can penetrate deep into the respiratory system and is transported long distances by the wind. "Therefore, symptoms can occur in regions where no birches are currently blooming," explains Guillod.
What Affected Individuals Can Do Now
Around 20 percent of the Swiss population is affected by pollen allergies, making hay fever one of the most common allergic conditions in the country. Allergy sufferers should closely monitor current pollen levels: on the website pollenundallergie.ch and in the free 'Pollen-News' app, it is possible to see in real-time how severe the exposure is in each region.
Those who already know they react to pollen should start the recommended treatment early. In cases of persistent or severe symptoms, a medical examination is advisable. For questions about symptoms or next steps in everyday life, the free aha! infoline is available at: 031 359 90 50 or aha.ch/infoline.