Urban/rural differences in the prevalences of airway diseases, allergies, and sensitizations in 6-year-old children from East and West Germany

Urban/rural differences in prevalences of airway diseases, allergies, and s ensitizations were studied in 19,090 6-year-old children from East and West Germany. The impact of SO2 and particulate matter on these differences wer e analyzed. The prevalences of sensitizations, positive specific IgE antibo dies against pollen, house dust mites or cat dander, were investigated in 3 699 children. The urban/rural differences in concentrations of SO2 and susp ended particles were larger in East than in West Germany. A logistic regres sion model was used to adjust for the possible confounding effects of socio demographic factors and indoor air quality. In East and in West Germany the odds ratios describing urban/rural differences were significantly greater than one in most of the 13 analyzed airway diseases, -symptoms, and allergi es. These odds raties for infectious airway diseases and symptoms were grea ter in East than in West Germany and were reduced in East Germany when incl uding the pollution values into the model (for frequent cough from 2.13 [CI 95 1.76 - 2.58] to 1.78 [CI95 1.42 - 2.20]). In West Germany only, the prev alences of sensitizations were slightly higher in urban than in rural areas and the prevalence of sensitizations against cat dander was significantly higher. An enhancement of the urban/rural effect in sensitized children was observed for bronchi tis in East Germany. The higher prevalences of allerg ies and sensitizations (West) in the urban compared to the rural areas cann ot be explained by differences in air pollution with SO2 and suspended part icles or by an enhancement of the effect in sensitized children.