A linear structural equation modeling procedure was used to explore the mechanisms and pathways for lead intake among urban children and the relative contribution of various lead sources to lead-contaminated house dust. Dust lead levels were significantly associated with children's blood lead levels, both indirectly and directly via hand lead. Both soil and paint lead contributed to dust lead levels, but paint contributed significantly more lead to house dust than soil (P < 0.001). Black race and income level both directly affected children's blood lead levels. Finally, time spent outdoors was associated with children putting soil or dirt in their mouths which was, in turn, associated with children's blood lead levels. These data indicate that mouthing behaviors are an important mechanism of exposure among urban children with low-level elevations in blood lead and that lead-based paint is a more important contributor of lead to house dust than is lead-contaminated soil.