The paper presents the results of geochemical investigations carried out in the city of Prague. Czech Republic, between the years 1994-1997, by the Czech Geological Institute, National Institute of Public Health and Hygiene Stations of Prague. Exposure assessment for children as the most sensitive population, based on soil ingestion pathway, indicates that lead is the major pollutant of concern, especially in the central regions of the city. Direct exposure assessment was done by analyzing blood and urine samples collected from children aged 3-6 years. Blood lead levels were the only biomarker significantly higher as compared to the control group (32.1 +/- 17.4 microg/l, 25.1 +/- 15.4 microg/l). This pilot study supports the establishment of a new sub-system within the already existing System of Monitoring the Environmental Impact on Population Health of the Czech Republic.