title: Relationship between bone lead and other indices of lead exposure in smelter workers.
abstract: The relationship between blood lead (B-Pb) indices and bone lead was determined in 81 smelter workers. Lead exposure had changed dramatically since the smelter opened 27 years ago; therefore, workers were stratified by years employed. Seventy workers, hired prior to 1979 (Group 1), had a mean (range) age of 46 years (35-64), mean years of employment 23 (16-27), mean years of education 8 (0-13), mean B-Pb 26 micrograms dl-1 (13-43), mean time-weighted average (TWA) B-Pb 44 micrograms dl-1 (23-57) and mean integrated blood lead index (IBL), 983 micrograms Pb year dl-1 (537-1437). Eleven workers, hired after 1978 (Group 2), had a mean age of 34 years (24-55), mean years of employment 11 (5-14), mean years of education 11 (8-12), mean B-Pb 26 micrograms dl-1 (8-13), mean TWA 33 micrograms dl-1 (17-44) and mean IBL 378 micrograms year dl-1 (81-555). Bone lead measured in the mid-tibia used K-X-ray fluorescence. Mean bone lead in Group 1 and Group 2 was 45 (-7-90) and 11 (-12-33) micrograms Pb (g bone mineral)-1, respectively. Linear regression analysis demonstrated a significant relationship between bone lead and B-Pb indices. B-Pb accounted for 10.8%, years employed 12.7%, TWA 31.4% and IBL 36% of the bone lead variance. Using a previously established relationship, the mean bone lead predicted a mean B-Pb content of approximately 8 micrograms dl-1 in Group 1 as compared to 2 micrograms dl-1 in Group 2. The mean B-Pb was 26 micrograms dl-1 in both groups despite differences in contribution from bone stores. Differential contribution of ambient air lead to B-Pb in the two groups of current workers with similar job titles may reflect use of personal protective equipment.
authors.affiliation: Center for Occupational and Environmental Neurology, Baltimore, MD, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Bleecker
authors.forename: F E
authors.initials: FE
authors.lastname: McNeill
authors.forename: K N
authors.initials: KN
authors.lastname: Lindgren
authors.forename: V L
authors.initials: VL
authors.lastname: Masten
authors.forename: D P
authors.initials: DP
authors.lastname: Ford
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis*; D001842:Bone and Bones / Q000737:chemistry*; D006801:Humans; D007854:Lead / Q000032:analysis*; D008669:Metallurgy; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects; D011524:Protoporphyrins / Q000032:analysis; D013977:Tibia / Q000737:chemistry
chemical_list: D015415:Biomarkers; D011524:Protoporphyrins; C017803:zinc protoporphyrin; D007854:Lead