title: Blood lead concentration and delayed puberty in girls.
abstract: BACKGROUND
  Environmental lead exposure has been linked to alterations in growth and endocrine function. It is not known whether such exposure affects pubertal development.
  
  
  METHODS
  We analyzed the relations between blood lead concentration and pubertal development among girls (defined as females 8 to 18 years of age) who were enrolled in a cross-sectional study (the third National Health and Nutrition Examination Survey) in which race was self-reported or proxy-reported: 600 were non-Hispanic white, 805 were non-Hispanic African-American, and 781 were Mexican-American girls. Puberty was measured on the basis of the age at menarche and Tanner stage for pubic-hair and breast development.
  
  
  RESULTS
  Geometric mean lead concentrations were less than 3 microg per deciliter (0.144 micromol per liter) in all three groups. As compared with concentrations of 1 microg per deciliter (0.048 micromol per liter), lead concentrations of 3 microg per deciliter were associated with decreased height (P<0.001), after adjustment for age, race, and other factors, but not with body-mass index or weight. Blood lead concentrations of 3 microg per deciliter were associated with significant delays in breast and pubic-hair development in African-American and Mexican-American girls. The delays were most marked among African-American girls; in this group, the delays in reaching Tanner stages 2, 3, 4, and 5 associated with a lead concentration of 3 microg per deciliter as compared with 1 microg per deciliter were 3.8, 5.3, 5.8, and 2.1 months, respectively, for breast development and 4.0, 5.5, 6.0, and 2.2 months, respectively, for pubic-hair development; the associated delay in age at menarche was 3.6 months. In white girls, there were nonsignificant delays in all pubertal measures in association with a lead concentration of 3 microg per deciliter.
  
  
  CONCLUSIONS
  These data suggest that environmental exposure to lead may delay growth and pubertal development in girls, although confirmation is warranted in prospective studies.
authors.affiliation: National Center for Environmental Assessment, Office of Research and Development, Environmental Protection Agency, Washington, DC 20460, USA. selevan.sherry@epa.gov
authors.forename: Sherry G
authors.initials: SG
authors.lastname: Selevan
authors.forename: Deborah C
authors.initials: DC
authors.lastname: Rice
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hogan
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Euling
authors.forename: Andrea
authors.initials: A
authors.lastname: Pfahles-Hutchens
authors.forename: James
authors.initials: J
authors.lastname: Bethel
mesh_terms: D000293:Adolescent; D044383:Black People; D002648:Child; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D007854:Lead / Q000009:adverse effects / Q000097:blood*; D007855:Lead Poisoning / Q000150:complications; D016015:Logistic Models; D008572:Menarche / Q000187:drug effects / Q000208:ethnology; D017058:Mexican Americans; D009749:Nutrition Surveys; D011627:Puberty / Q000187:drug effects* / Q000208:ethnology; D014481:United States; D044465:White People; D001741:Black or African American
chemical_list: D007854:Lead