Air pollution and allergy in Germany: Surprising results of data obtained after reunification

Abstract

The German reunification gave the unique opportunity to investigate the development of allergies in two population groups with similar genetic background but a different environment. Three surprising results were gained in epidemiological comparison studies done in Germany after 1989: 1. The prevalence of allergies was higher in West than in East Germany. This was especially true for diagnoses of hay fever and birch pollen sensitization. 2. Allergies in East Germany increased after the reunification in spite of decreasing traditional outdoor air pollution with sulfur dioxide and coarse particles. 3. The change to more favorable indoor conditions in East Germany did not lead to fewer allergies. Unexpectedly unfavorable indoor conditions like single room heating and crowding were associated with less hay fever and pollen sensitization and partly explained the observed trends in allergy development. The results gained in the East-West comparison studies were driving forces for a change in the paradigms of allergy research.