This is mainly due to the association with "unfavourable indoor air".
For unfavourable indoor air in East Germany, the frequency of colds was increased, but of eczema and sensitisation decreased.
Furthermore, the frequencies of small living place, unfavourable indoor air and damp housing condition decreased over time, the latter also with a peak in the mid-nineties.
If an oven heated with fossil fuel or cooking with gas existed then "unfavourable indoor air" in the child's home was assumed.
Furthermore, most of the health indicators were significantly associated with one or more living conditions such as living as a single child, unfavourable indoor air, damp housing condition, maternal smoking during pregnancy or living near a busy road.
Unfavourable indoor air by heating with fossil fuels or cooking with gas which was more prevalent in less educated families in East Germany was observed as a protective factor against sensitisation with pollen and partly explained differences in pollen sensitisation between groups of different educational level.
With the exception of "unfavourable indoor air" in West Germany, all living conditions were significantly (p < 0.1) associated with parental educational level (table 4): Less educated parents more frequently had a single child, lived in a small or damp living place or near a busy road, or heated with coal or gas.
People with a low socioeconomic status were also more likely to be exposed to unfavourable neighbourhood conditions like air pollution [ 16, 19].
The effect of SES on respiratory symptoms and impaired lung function could partly be explained by known unfavourable living conditions, as could smoking and ambient air pollution, in those women with less school education.
The soils were compacted to 95% of their specific proctor density, resulting in bulk densities of 1.4 1.7 g cm−3, reflecting considerably unfavourable conditions for methane oxidation due to reduced air-filled porosity.
