Dietary exposure of children in lead-laden environments

Children are the most susceptible population to lead exposure because of th ree interacting factors; they have more opportunity for contact with lead s ources due to their activities, lead absorption occurs more readily in a ch ild compared to an adult, and the child's development is more vulnerable to lead than adults. Low levels of lead in the blood have been shown to cause adverse health effects; the level of concern for children is currently 10 mug/dl. The contribution of dietary exposure of lead to increased blood lea d levels (PbB) is not well characterized. This study was conducted to measu re potential dietary lead intakes of children 2 to 3 years of age who live in homes contaminated with environmental lead. Objectives were to estimate lead intakes for children consuming food in contaminated environments, reco gnizing unstructured eating patterns and to investigate if correlations exi st between daily dietary exposure and measured PbB. Dietary exposure was ev aluated by collecting samples that were typical of the foods the young chil dren ate in their homes. A 24-h duplicate of all foods plus sentinel foods, i.e., individual items used to represent foods contaminated during handlin g, were collected from 48 children. Ten homes were revisited to obtain info rmation on the variation in daily dietary intakes. Drinking water was evalu ated both as part of the segregated beverage sample composite and by itself . Additional information collected included lead concentrations from hand w ipes, floor wipes, and venous blood, and questionnaire responses from the c aregiver on activities potentially related to exposure. Activities and hygi ene practices of the children and contamination of foods in their environme nt influences total dietary intake. Estimated mean dietary intakes of lead (29.2 mug Pb/day) were more than three times the measured 24-h duplicate-di et levels (8.37 mug Pb/day), which were almost six times higher than curren t national estimates (1.40 mug Pb/day). Statistically significant correlati ons were observed between floor wipes and foods contacting contaminated sur faces, hand wipes and foods contacting contaminated hands and surfaces, and hand wipes and floor wipes. This study indicates that the dietary pathway of exposure to lead is impacted by eating activities of children living in lead-contaminated environments and that analysis of foods themselves is not enough to determine excess dietary exposures that are occurring.