Forecast of Pollination Dates and Relation to Onset of Allergic Pathology

Forecasting pollination would help allergists to establish an appropriate prevention for allergic patients. Previous studies have related meteorological variables to airborne pollen counts; patients suffer allergy episodes before the peak of pollen is reached. A 10-year study was done in Saint-Etienne (France) by a multi-disciplinary team (medical doctors, meteorologists, plant biologists). The frequency distribution of patients with pollinosis was obtained from mid-January to August every year. The meteorological station recorded the temperatures daily; pollen counts were obtained with a pollen trap. The maturation stages of trees (ash, birch) and graminaceae (dactyl and meadow grass) were followed by weekly sampling and provided the exact date of pollination. Mathematical models were built to predict the developmental stages of plant growth and the values were compared with the exact dates obtained every year. The frequency distribution of allergic patients was either mono or biphasic according to the evolution of daily temperatures. The maximum peak of patients always preceded the peak of graminaceae over the 10-year period. Different models were found to adequately predict the pollination dates: a Q ₁₀-based algorithm best described the pollination date of trees; a weighted Q ₁₀ algorithm best reflected the pollination of graminaceae.