title: Longitudinal changes in bone lead levels: the VA Normative Aging Study.
abstract: OBJECTIVE
  Bone lead is a cumulative measure of lead exposure that can also be remobilized. We examined repeated measures of bone lead over 11 years to characterize long-term changes and identify predictors of tibia and patella lead stores in an elderly male population.
  
  
  METHODS
  Lead was measured every 3 to 5 years by k-x-ray fluorescence and mixed-effect models with random effects were used to evaluate change over time.
  
  
  RESULTS
  A total of 554 participants provided up to four bone lead measurements. Final models predicted a -1.4% annual decline (95% CI: -2.2 to -0.7) for tibia lead and piecewise linear model for patella with an initial decline of 5.1% per year (95% CI: -6.2 to -3.9) during the first 4.6 years but no significant change thereafter (-0.4% [95% CI: -2.4 to 1.7]).
  
  
  CONCLUSIONS
  These results suggest that bone lead half-life may be longer than previously reported.
authors.affiliation: Cardiovascular Epidemiology Research Unit, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA. ewilker@bidmc.harvard.edu
authors.forename: Elissa
authors.initials: E
authors.lastname: Wilker
authors.forename: Susan
authors.initials: S
authors.lastname: Korrick
authors.forename: Linda H
authors.initials: LH
authors.lastname: Nie
authors.forename: David
authors.initials: D
authors.lastname: Sparrow
authors.forename: Pantel
authors.initials: P
authors.lastname: Vokonas
authors.forename: Brent
authors.initials: B
authors.lastname: Coull
authors.forename: Robert O
authors.initials: RO
authors.lastname: Wright
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.forename: Howard
authors.initials: H
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001842:Bone and Bones / Q000737:chemistry*; D006207:Half-Life; D006801:Humans; D007854:Lead / Q000032:analysis*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010329:Patella / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D013977:Tibia / Q000737:chemistry; D055815:Young Adult
chemical_list: D007854:Lead