The 2025 [1] pollen season has officially started in Belgium, marked by the first peak of alder and hazel pollen.
This seasonal shift poses a significant health risk for millions of allergy sufferers across Flanders and parts of the Netherlands. The timing and intensity of pollen release can lead to severe respiratory distress and other allergic reactions if not managed with proper medical precautions.
Sciensano, the national aerobiological network, is monitoring the levels across the region. The agency said that the initial surge is driven specifically by alder and hazel trees [2]. These species are typically the first to release grains into the air during the spring transition.
Weather patterns are playing a critical role in the current concentration of allergens. Dry and windy conditions are accelerating the release of pollen from trees and dispersing it more widely across the landscape [1]. Such weather often leads to higher concentrations of particles in the air, increasing the likelihood of symptom onset for sensitive individuals.
Sciensano said, "Wees alert op droge en winderige dagen" [1]. This warning emphasizes the need for caution during specific meteorological windows when the air quality may deteriorate for those with hay fever.
In other regions, such as Helmond in the Netherlands, similar trends have been observed. A measurement team at Elkerliek hospital said, "Het aantal pollen in de lucht groeit" [4]. This indicates that the surge is not isolated to Belgium but is a broader regional phenomenon affecting the Low Countries.
Health authorities continue to urge the public to stay informed about daily pollen counts. Sciensano said, "Wees extra alert" [3], suggesting that the current peak may be particularly potent. Residents are encouraged to limit outdoor activity during peak hours on windy days to minimize exposure.
“"Wees alert op droge en winderige dagen"”
The early arrival and intensity of the 2025 pollen season highlight the sensitivity of aerobiological cycles to specific weather triggers. When dry and windy conditions coincide with the blooming of alder and hazel, the resulting pollen spikes can overwhelm standard allergy management, potentially increasing the burden on primary healthcare services in Belgium and the Netherlands.
