Overview of the study design, participation and field work of the German Environmental Survey on Children 2003-2006 (GerES IV).

The German Federal Environment Agency carried out its fourth German Environmental Survey (GerES IV), which is the first survey on children only and the environment-related module of the German Health Interview and Examination Survey for Children and Adolescents (German acronym: KiGGS), conducted by the Robert Koch Institute (RKI). The German Environmental Surveys are nationwide population studies conducted to determine the exposure to environmental pollutants, to explore exposure pathways and to identify sub-groups with higher exposure. GerES IV was conducted on randomly selected 1790 children aged 3-14 years from the cross-sectional sample of KiGGS. The participants of GerES IV lived in 150 sampling locations all over Germany. Field work was carried out from May 2003 to May 2006. The response rate in GerES IV was 77.3%. Due to the fact that participation in GerES IV was limited to children that had previously participated in the KiGGS study, the total response rate in GerES IV resulted in 52.6%. Response rates did neither differ significantly between West and East Germany, nor between different community sizes, age groups and gender. The basic study programme included blood samples, morning urine, tap water and house dust as well as comprehensive questionnaire-based interviews. In addition, subgroups were studied with regard to "noise, hearing capacity and stress hormones", "chemical contamination of indoor air" and "biogenic indoor contamination". A key element of the field work in GerES IV was a home visit to carry out interviews, conduct measurements and collect samples. An exception was blood sampling which was carried out within KiGGS. The quality of field work, data collection, evaluation, and chemical, biological and physical analyses was successfully evaluated by internal and external quality assurance. This comprehensive overview aims at giving other research groups the opportunity to compare different study designs or to adapt their own design to get comparable results.