Age-specific risk factors for lead absorption in children.

The relationship of blood lead levels to environmental and individual characteristics is analyzed in a large sample of children residing near a lead smelting complex, with particular emphasis on the identification of age-related risk factors. Exceptional variation in both blood leads and its determinants within the study region facilitated the simultaneous detection of several significant risk factors for each year of age from 1 to 9 yr. The strongest predictor of blood lead at all ages was air lead, but the secondary risk factors were age dependent. Household dustiness was significantly related to blood lead in young children, especially those under 2 yr of age; soil lead may be an important source of ingested lead for children between 2 and 7 yr. Other significant effects included that of pica at about 2 yr of age, a slight effect of the occupational category of the fathers of 5- to 8-yr-old children, and a tendency for 8- and 9-yr-old boys to have higher blood leads than girls of the same age. Lead concentration in household paint was not a significant risk factor. These results suggest that a multifactorial approach to the prevention of excessive lead absorption by children is required.