Our studies will be carried out in one of the four sub-economic areas, that were previously used in the baseline assessment in and near Marrakesh, Morocco (exact site still needs to be determined according to extend of lead contamination on the level of human population). Body lead burden and iron status will be determined, and associations between these examined using a cross-sectional design. For this purpose, blood and urine samples will be collected from two groups (preschool and school-aged children), residing in an area of high lead exposure.