concentrations already higher than 2023

Birch pollen has already been present in the air for several weeks but its concentrations have been particularly high in recent days. While the 2024 season is not over, they already far exceed the values ​​recorded in 2023, notes the Rnsa (National Aerobiological Monitoring Network) in its weekly bulletin.

Rising temperatures – with records broken in the Rhône – and the maintenance of sunny weather are conducive to the dispersion of these particularly allergenic pollens. In the department, the allergic risk is therefore classified at the “high” level.

Plane tree pollens also remain present with a moderate level allergic risk. The micro-needles contained in plane tree husks, coming from the degradation of the female flower heads from the previous year, are very irritating and can cause coughing.

Although oak and grass pollens are increasing in intensity, the allergic risk is still classified as low in the Rhône. However, certain grasses are also flowering several weeks earlier than in a typical year, underlines the Rnsa. This is particularly the case for the meadow foxtail, the timothy, the meadow grass and the timothy. This precocity of flowering is attributable to the great mildness and abundant precipitation of recent weeks and months which favor the growth of these herbaceous plants.