Allergenic tree pollen season start in Europe

The impact of pollen allergens on human health is primarily manifested by allergic diseases. Exposure to allergens from airborne pollen or their inhalation can trigger allergic responses of nose, eyes and bronchi (asthma). These allergic reactions can lead to sleep disturbance, decreased quality of life due to impaired mental health, productivity loss or decreased school performance of children, and high healthcare costs. The impact of climate change on pollen seasons, concentrations and allergenicity are expected to lead to increased exposure of the European population to pollen and aeroallergens in the future.

Caveats

The indicator is based on the season timing only and assumes the same amount pollen released into the air every year – enough to induce allergies – and the same vegetation distribution for all years. In reality, the clinically relevant pollen season depends not only on the phenological season but also on absolute pollen concentrations, which fluctuate for trees strongly across years. Predicting pollen concentrations is difficult, however, and currently not yet possible at European-wide level, while it is fair to assume that the onset of the pollen season – also an important health-related indicator – is mainly dependent on temperature regardless of whether pollen concentrations are high or low.