AEROBIOLOGICAL DYNAMICS OF THE CUPRESSACEAE POLLEN IN SPAIN, 1992-98

Abstract

SUMMARY: In Spain, the Cupressaceae family comprises two native genera: Juniperus(six species) and Tetraclinis (one species). It also includes several exotic genera grown asornamental or forest trees, such as Cupressus (numerous species, but C. sempervirens andC. arizonica are the most abundant), Chamaecyparis and Platycladus (Thuja) as the mostcommon genus. The pollen type Cupressaceae includes the families Taxaceae andTaxodiaceae, and their pollens show cross-reactivity. In recent decades, allergy to thesepollens has been clearly recognized. This study analyses the pollen records for the period1992–98 at 15 sites in the Spanish Aerobiology Network (Red Espanola de Aerobiologia,REA). There is no part of Spain free of Cupressaceae pollen and its abundance depends onthe number of ornamental plants in the surroundings of the trap and not on geographicalparameters. In urban areas, huge variation in the quantities of pollen from year to year isnot only due to weather but also to gardening manipulations of the ornamental species.The pollen is present all year round, pollination beginning in September and ending inAugust, and the maximum concentrations occurring usually in February, but sometimes inMarch, January, December, or April. In most locations, the pollen concentrations werehighest in the periods 1996–97 and 1997–98. In this paper, the use of pollen categoriesinstead of pollen concentrations is recommended. This is to simplify the presentation ofthe information, specially when defined specifically for the pollen type and taking intoconsideration the allergy sensitization level. The concept of main pollen season (MPS)does not seem relevant for the characterization of the Cupressaceae aerobiological dynamics.KEY WORDS: Aerobiology, allergy, Cupressaceae, Cupressus, Juniperus, pollen categories,pollen levels, Spain.