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Association Between Aminolevulinate Dehydrase Genotypes and Blood Lead Levels in Children from a Lead-Contaminated Area in Antofagasta, Chile

  • F. Pérez-Bravo
  • M. Ruz
  • M. J. Morán-Jiménez
  • M. Olivares
  • A. Rebolledo
  • J. Codoceo
  • V. Sepúlveda
  • A. Jenkin
  • J. L. Santos
  • A. Fontanellas
Article

Abstract

Childhood environmental lead exposure in the city of Antofagasta, Chile, was generated by the accumulation of recently removed lead stores derived from mining activities for a long period of time. Susceptibility to harmful lead effects may be associated with polymorphisms of delta-aminolevulinic acid dehydratase (ALAD) because of the differential binding of lead to the codified proteins. We assessed the associations and possible interactions among the following variables: blood lead levels, ALAD genotypes, and distance to the source of lead contamination in Chilean children exposed to lead contamination in Antofagasta, Chile. Ninety-three children were recruited from schools located near a lead- contaminated area. Lead blood levels were measured by atomic absorption spectrophotometry. ALAD genotypes were determined by polymerase chain reaction and restriction fragment-length polymorphism analysis. The frequency of the ALAD-2 allele was estimated at 0.054. Children with the ALAD-2 genotype had higher blood lead levels than noncarriers (p = 0.06). As expected, blood lead levels were inversely correlated with the distance from lead stores. Interestingly, ALAD-2 carriers were more frequent within the area defined by a distance of 200 m from lead deposits (27%) than in areas >200 m (5%) away. Children living within a maximum distance of 200 m from the lead stores showed higher blood lead levels in ALAD-2 carriers (geometric mean = 16.4 μg/dl, range 6 to 27) than in noncarriers (geometric mean = 12.1 μg/dl, range 0 to 26) without achieving statistical significance (p = 0.13). A trend for higher blood lead levels in ALAD-2 carriers compared with ALAD-1 homozygous children has been observed. Because ALAD-2 frequency was higher in subjects living within 200 m from the lead deposits, we hypothesized that a long-term selective pressure against the presence of the ALAD-1 allele is the cause of the overrepresentation of the ALAD-2 allele in children living in proximity to the recently removed lead stores.

Keywords

Lead Exposure Blood Lead Level Differential Binding Environmental Lead Lead Contamination 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag New York Inc. 2004

Authors and Affiliations

  • F. Pérez-Bravo
    • 1
  • M. Ruz
    • 2
  • M. J. Morán-Jiménez
    • 3
  • M. Olivares
    • 1
  • A. Rebolledo
    • 2
  • J. Codoceo
    • 1
  • V. Sepúlveda
    • 4
  • A. Jenkin
    • 4
  • J. L. Santos
    • 1
  • A. Fontanellas
    • 3
  1. 1.Unidad de Nutrición Pública, Programa de Epidemiologia Genética, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, PO Box 138-11, SantiagoChile
  2. 2.Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, PO Box 13891, Correo 21, SantiagoChile
  3. 3.Centro de Investigación, Hospital Universitario 12 de Octubre, Avda. De Córdova s/n, 28041, MadridSpain
  4. 4.Departamento de Salud, Casilla 170, Campus Coloso, AntofagastaChile

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