Descriptive characteristics of the study population and exposure variables
Over half of the children (55.2 %) were from families with high level of parental education while only 2.4 % were from families with low level of parental education (Table 1). This was the only systematic difference between the analytic sample compared to the original LISA Leipzig population where the above-mentioned numbers were 48 % and 5 %, respectively.
The highest prevalence of doctor diagnosed asthma (4.5 %) was observed at 7 and at 11 years (Table 2). The highest prevalence of AR (12.2 %) was observed at 11 years. 47.4 % children at 15 years were sensitized to aeroallergens. The peak of sensitization to food allergens (16.5 %) was reached at 10 years.
Descriptions of the exposure variable categories for all three buffer sizes are provided in Table E2. Mean and standard deviations for NO2 and summer ozone levels were 33.5±4.5 µg/m3 and 84.7±3.9 µg/m3, respectively.