Abstract The present study was done between 1989 and 1991 and performed on 263 children 7 to 9 years of age who lived in Mexico City. The goal was to determine the association between risk factors entering the body through the respiratory or digestive path and lead concentration in deciduous teeth. Exposure to risk factors was surveyed through a questionnaire: lead was determined by atomic absorption spectrophotometry with a graphite oven and reported in μg Pb/g tooth. Statistical significance was found for the habit of sucking toys OR 4.98 (IC 95% 1.23–28.67), the use of glazed earthenware utensils for the preparation and serving of food and drinks OR 2.47 (IC 0.80–8.47), and the ingestion of tinned food, particularly juices OR 3.31 (IC 1.03–12.50). No positive results were found for risk factors involving the respiratory path. A possible explanation for these results is a different risk level for each of the two paths of access.