Variations of airborne summer pollen in southwestern Spain.

The fact that a considerable proportion of pollen allergy sufferers have an upsurge of symptoms in summer prompted us to study the airborne pollen types present in the air of Huelva (southwestern Spain) during the months of July, August and September. A Cour-type pollen sampler was installed in the center of the city. In these months of elevated climatological dryness (high temperatures and almost complete absence of rain), 26 different pollen types were detected (results from four years of observation: 1989-1992). Quantitatively outstanding were Amaranthaceae/Chenopodiaceae, Eucalyptus, Gramineae (Poaceae), Helianthus and Ligustrum (comprising 86.06% of the pollen measured). Of these types, only extracts of Gramineae and Amaranthaceae are included in the skin tests and immunotherapy practiced in the region. Given the allergic potential of the pollen of Ligustrum, Helianthus, Eucalyptus and Palmaceae, we performed aerobiological evaluations, which may be useful when diagnosing summer pollen allergies.