POLLEN-RELATED ALLERGY IN EUROPE

The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropal ynologic and allergologic studies have progressed to meet this need, a nd extensive international networks now provide regular pollen and hay -fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently , pollen calendars differ from one area to another; however, on the wh ole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Eu rope, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Medite rranean areas favor the production of pollen types that are rarely fou nd in central and northern areas of the continent (e.g., the genera Pa rietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultura l factors (e.g., importation of plants for urban parklands) and greate r international travel (e.g,, the expansion of the ragweed genus Ambro sia in France, northern Italy, Austria, and Hungary). Studies on aller gen-carrying paucimicronic or submicronic airborne particles, which pe netrate deep into the lung, are having a relevant impact on our unders tanding of pollinosis and its distribution throughout Europe.