[Sensitization to pollens in a changing environment: Israel].

Israel was originally a country with desert climate and extensive agriculture. During the last 40 years, due to artificial irrigation, a rich vegetation and intensive agriculture have developed. Hayfever prevalence has risen between 1952 and 1986 from an average of 0.3% to 6.3% (with a range from 4% in the urban to 15% in the rural communities). Considering that significant (P less than 0.001) impact of pollen quantity upon hayfever incidence, an elementary pollen information system was organized (as described in the article) to help both allergists and allergic patients in their joint effort to avoid the harmful effect of a changing environment.