Allergenic tree pollen

Exposure to allergens from airborne pollen or their inhalation can trigger allergic responses in the nose, eyes, and bronchi (asthma), in turn causing 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 is expected to increase exposure of the European population to pollen and aeroallergens in the future.

Calculations of the clinically-relevant pollen seasons are performed using an atmospheric composition model. This indicator monitors the season severity (daily pollen per m3) for birch and alder (1980–2022), and olive (1990–2022) calculated from the European Pollen Reanalysis v.1.0, which computes plant development during spring, pollen release, transport, and removal using temperature, land cover, and tree species, and combines them with pollen observations of the European Aeroallergen Network. The indicator also provides a metric of pollen season timing (start, end, and duration in days) and change in severity by comparing the decadal medians for 2013–22 with 1980–89 for birth and alder and 1990–99 for olive.

Caveats

The indicator makes assumptions about the vegetation distribution map remaining constant for all years and ignores annual fluctuations in tree pollen concentrations. However, predicting the absolute level of pollen season for each specific year is a difficult task, and no adequate European-wide solution exists for it this far. Data were lacking for earlier observations, so the analysis was limited to 1980-2022 for birch and alder and 1990-2022 for olive.