Lead and cadmium concentration was determined in the hair of 327 school children living in a wastewater spreading field of Marrakesh (Morocco). The influence of age, sex, food habits and family occupation on the children's hair Pb and Cd concentration was also evaluated. Girls had more metal in their hair than boys (16.5+/-5.4 μg/g and 12.5+/-3.5 μg/g, respectively). However, for Cd the boys had more metal (2.9+/-0.6 and 2.2+/-0.4, respectively) but the difference was not statistically significant and metal levels decreased with age. Family occupation, direct contact with wastewater, customs and food habits were the most significant factors influencing the metal content of children's hair. The average Pb and Cd content were higher in the exposed children (14.8+/-4.5 μg/g and 2.5+/-0.5 μg/g, respectively) than in the non-exposed children (4.6+/-2.2 μg/g and 0.6+/-0.2, respectively), but the difference was not statistically significant. This study shows that in this area all the population (especially children) was extremely exposed to the danger caused by potentially toxic metals.