German Environmental Surveys (GerESs) are large scale population studies which have been carried out on adults in 1985/86, 1990/92 and 1998 and on children aged 6-14 years in 1990/92. GerES IV is the first survey focussing exclusively on children [Becker, K., Schulz, C., Babisch, W., Dürkop, J., Roskamp, E., Seiwert, M., Szewzyk, R., Ullrich, D., Seifert, B., 2005. German Environmental Survey for Children (GerES IV) 2003-2006. Pullut. Atmos. 188, 475-479]. GerES IV included a representative sample of 1790 children aged 3-14 of the participants of the National Health Interview and Examination Survey on Children and Adolescents. The primary goal of GerES IV is not only to analyse and document the extent, distribution and determinants of German children's exposure to environmental pollutants but to discover links between environmental exposure and health. Results will help develop preventive measures and advance further research. They might provide the basis for environmental and public health policy decisions. Precondition to achieve this task is a description of the data on exposures and the data on health outcomes. This work is currently performed at the Federal Environment Agency. First results show a remarkable decrease of the blood lead level of German children aged 6-14 years from 32.3 microg/l in 1990/92 (GerES II) to 16.3 microg/l in GerES IV which is the lowest mean lead concentration determined in German studies so far. None of the children had a value exceeding 100 microg/l. In GerES IV, the following health-related issues will be primarily examined: the relationship between sensitisation against mould spores and the occurrence of mould in households, irritation of eyes and respiratory system caused by formaldehyde, other aldehydes, or total volatile organic compounds (TVOC); the impact of non-occupational noise on hearing loss, stress and sleep disturbances, and the connection between contact allergies, nickel and scents. 9.5% of the children showed a sensitisation to at least one of the moulds examined (Penicillium (notatum) chrysogenum, Aspergillus versicolor, Wallemia sebi, Eurotium spp., Alternaria alternata). The most frequent sensitisation was against Penicillium chrysogenum. GerES IV might broaden the knowledge in terms of environmental causes of health outcomes. Children of smoking mothers showed higher mean cotinine concentrations than children living with a smoking father, regardless whether they smoked daily or occasionally. Results from the GerES IV pilot study showed a relation between environmental tobacco smoke (ETS) exposure and an increased susceptibility to infections and inflammations of the middle ear.