Pollen data have been collected from 66 stations, situated in 19 European countries thanks to the initiative of both the Working Group «European Aeroallergen Network» (of the Int. Assoc. of Aerobiology) and the Subcommittee «Aerobiology of inhalant allergens» of the European Academy of Allergology and Clinical Immunology. Volumetric data over periods of 3 to 5 years (up to 1988) were included, and 15 both aerobiologically and allergologically relevant taxa were selected. Geographically adjacent stations were grouped together into regions looking at the peak period of the airborne grass-pollen presence. The result is a collection of 21 regional European pollen calendars, some of which are covering several countries (e.g. «Western Europe»), others are applicable only to a part of one country (e.g. «Southern Italy»).
Comparing the calendars, general features are the South-to-North delay shift in the appearance of tree-pollen types in Spring, and the reverse shift for the weed-pollen types in late summer. The presence ofAmbrosia pollen in the air in several parts of Central Europe is clearly shown.