Blood pressure of 8-14 year old children in relation to traffic noise at home--results of the German Environmental Survey for Children (GerES IV).

Objectives: The German Environment Agency carried out its fourth German Environmental Survey (GerES IV) from 2003 to 2006, which was especially for children. 1048 children, 8-14 years of age, were randomly selected from all over Germany. The sample is representative of children in this age group living in Germany with respect to gender, community size, and region.

Methods: Blood pressure was measured under standardized conditions at clinical study centers. During home visits the children and their parents were asked about leisure activities, housing conditions and environmental factors, including traffic exposure of their homes. Orientating short-term noise measurements were carried out in front of the children's (bed-) room to validate the subjective ratings of the traffic volume (categories: no street, low, moderately, high/extremely high).

Results: With respect to the subjective rating of "type of street" (traffic volume) the lowest blood pressure readings were found in children whose room was facing a street with 'low traffic'. The highest readings were found in the group where the children's rooms were facing a street with a 'high or extremely high traffic' volume. The difference between the two groups was 1.8mm Hg (95% CI: 0.1 to 3.5, p=0.036) for systolic and 1.0mm Hg (95% CI: -0.4 to 2.4, p=0.148) for diastolic blood pressure. With respect to the short-term noise measurements, significant blood pressure increases of 1.0mm Hg (95% CI: 0.3 to 1.6, p=0.004) and 0.6mm Hg (95% CI: 0.1 to 1.2, p=0.025), respectively, were found per 10 dB(A) increment of the noise level.

Conclusions: The results show that road traffic noise at home is a stressor that could affect children's blood pressure.