Dietary intake of lead and blood lead concentration in early infancy.

Under circumstances of low prenatal exposure to lead and low nondietary exposure to lead postnatally, four breast-fed infants and 25 formula-fed infants were studied to determine the relation between dietary intake of lead and blood lead concentration. From 8 through 111 days of age, the mean dietary intake of lead by the formula-fed infants was 17 micrograms/day (3 to 4 micrograms/kg/day), and intake of lead by the breast-fed infants was estimated to be only slightly greater. The mean blood lead concentration at the age of 112 days was 6.1 micrograms/dL. From 112 through 195 days of age, 17 infants continued in the study: ten received a mean dietary intake of lead of 16 micrograms/day, and seven received a mean intake of 61 micrograms/day. At 196 days of age, mean blood lead concentrations were significantly different (7.2 and 14.4 micrograms/dL, respectively).