title: Arsenic exposure and cognitive performance in Mexican schoolchildren.
abstract: BACKGROUND
  Previous studies have suggested an effect of high arsenic concentration on cognitive and neurobehavioral function in humans.
  
  
  OBJECTIVE
  Our goal was to identify demographic and nutritional factors that are associated with As exposure and the influence of this exposure on cognitive function in school-age children.
  
  
  METHODS
  We recruited 602 children 6-8 years of age living within 3.5 km of a metallurgic smelter complex in the city of Torreón, Mexico, to participate in a cross-sectional evaluation. Of these, 591 had complete anthropometry, iron, and zinc status by biochemical measurements in serum, blood lead concentration (PbB), and arsenic in urine (UAs), and 557 completed several cognitive performance tests.
  
  
  RESULTS
  The mean for UAs was 58.1 +/- 33.2 microg/L; 52% of the children had UAs concentrations > 50 microg/L, and 50.7% of children had PbB > or = 10 microg/dL. UAs concentration was associated with low socioeconomic status. Nutritional status indicators were not related to UAs concentrations. Linear and logistic regressions adjusted for hemoglobin concentration, PbB, and sociodemographic confounders showed a significant inverse association between UAs and Visual-Spatial Abilities with Figure Design, the Peabody Picture Vocabulary Test, the WISC-RM Digit Span subscale, Visual Search, and Letter Sequencing Tests (p < 0.05). Boys excreted significantly more UAs (p < 0.05) and were affected on different cognitive areas than girls.
  
  
  CONCLUSIONS
  Children living in an area contaminated with both As and lead showed that As contamination can affect children's cognitive development, independent of any effect of lead.
authors.affiliation: School of Natural Sciences, Universidad Autónoma de Querétaro, Division of Nutritional Sciences, Querétaro, Mexico. jlrosado@avantel.net
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Rosado
authors.forename: Dolores
authors.initials: D
authors.lastname: Ronquillo
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kordas
authors.forename: Olga
authors.initials: O
authors.lastname: Rojas
authors.forename: Javier
authors.initials: J
authors.lastname: Alatorre
authors.forename: Patricia
authors.initials: P
authors.lastname: Lopez
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Garcia-Vargas
authors.forename: María
authors.initials: M
authors.lastname: Del Carmen Caamaño
authors.forename: Mariano E
authors.initials: ME
authors.lastname: Cebrián
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Stoltzfus
mesh_terms: D001151:Arsenic / Q000633:toxicity* / Q000652:urine; D001288:Attention / Q000187:drug effects; D002648:Child; D003071:Cognition / Q000187:drug effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D004785:Environmental Pollutants / Q000633:toxicity* / Q000652:urine; D005260:Female; D006801:Humans; D007360:Intelligence / Q000187:drug effects; D007361:Intelligence Tests; D007854:Lead / Q000097:blood / Q000633:toxicity; D007858:Learning / Q000187:drug effects; D008297:Male; D008669:Metallurgy; D008800:Mexico