title: Occurrence of elevated protoporphyrin levels in relation to lead burden in infants.
abstract: Simultaneous blood lead (PbB), erythrocyte protoporphyrin (EP), and hematocrit measurements were made semiannually in 232 normal infants from 6 to 24 months of age. The PbB averaged 7 (SD = 5) and ranged from 0 to 64 micrograms/dl. The incidence of elevated EP, a marker for deranged heme synthesis, was unrelated to PbB at levels below 15 micrograms/dl but was fourfold greater among the infants with PbB above 15 micrograms/dl. This relationship persisted even after eliminating the 31 (4%) anemic (hematocrit less than 33%) samples. The confounding effects of iron deficiency are discussed.
mesh_terms: D002675:Child, Preschool; D004912:Erythrocytes / Q000032:analysis; D006400:Hematocrit; D006418:Heme / Q000096:biosynthesis; D006801:Humans; D007223:Infant; D007855:Lead Poisoning / Q000097:blood*; D011166:Porphyrins / Q000097:blood*; D011524:Protoporphyrins / Q000097:blood*
chemical_list: D011166:Porphyrins; D011524:Protoporphyrins; D006418:Heme