title: [Blood lead levels and poor school performance among children in Mexico City].
abstract: OBJECTIVE
  To describe the relationship between blood lead levels (BLL) and poor school performance.
  
  
  METHODS
  A cross-sectional study was carried out in 1996 among 792 schoolchildren aged 7-14 years, who attended the outpatient units of five pediatric hospitals of Mexico City. BLL was measured together with lead exposure and academic performance.
  
  
  RESULTS
  Reported BLL and geometric means (GM) were 8.6 microg/dL and 7.7 microg/dL, respectively. The main source of exposure was the use of glazed pottery (difference of use =-1.182; p = 0.000). Among schoolchildren who failed any school year, GM of the BLL was 8.1 microg/dL, compared with children who did not fail (GM = 7.6 microg/dL; p = 0.240). The risk of failing a school year between the 1st and 3rd grade with a BLL greater than 10 microg/dL was 1.73 (p = 0.012, IC 95% 1.13-2.66) and from 1st to 4th grade was 1.62 (p = 0.021, IC 95% 1.07-2.46).
  
  
  CONCLUSIONS
  Blood lead levels, among other conditions, may contribute to the failure in school performance observed in the children participating in this study.
authors.affiliation: Secretaría de Salud del Estado de Sonora, México.
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Leal-Escalante
authors.forename: Mary Carmen
authors.initials: MC
authors.lastname: Baltazar-Reyes
authors.forename: Montserrat
authors.initials: M
authors.lastname: Lino-González
authors.forename: Eduardo
authors.initials: E
authors.lastname: Palazuelos-Rendón
authors.forename: Fernando
authors.initials: F
authors.lastname: Meneses-González
mesh_terms: D000124:Achievement; D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007854:Lead / Q000097:blood*; D008297:Male; D008800:Mexico; D014505:Urban Population
chemical_list: D007854:Lead