| Arsenic Exposure and Cognitive Performance in Mexican Schoolchildren Jorge L. Rosado,1 Dolores Ronquillo,1 Katarzyna Kordas,2 Olga Rojas,3 Javier Alatorre,3 Patricia Lopez,4 Gonzalo Garcia-Vargas,5 María del Carmen Caamaño,1 Mariano E. Cebrián,6 and Rebecca J. Stoltzfus2 1School of Natural Sciences, Universidad Autónoma de Querétaro, Division of Nutritional Sciences, Querétaro, Mexico; 2Division of Nutritional Science, Cornell University, Ithaca, New York, USA; 3Department of Psychology, Universidad Nacional Autónoma de México, Mexico City, Mexico; 4Instituto Nacional de Ciencias Médicas y Nutrición, Mexico City, Mexico; 5Medical School, Universidad Juárez del Estado de Durango, Gomez Palacio, Mexico; 6Centro de Investigación y Estudios Avanzados, National Polytechnic Institute, Mexico City, Mexico 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 µg/L ; 52% of the children had UAs concentrations > 50 µg/L, and 50.7% of children had PbB ≥ 10 µg/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. Key words: arsenic, children, chronic exposition, cognitive performance, Mexico. Environ Health Perspect 115: 1371–1375 (2007) . doi:10.1289/ehp.9961 available via http://dx.doi.org/ [Online 22 May 2007]
Address correspondence to J.L. Rosado Apartado Postal No 31, Desarrollo San Pablo, Querétaro Qro. México. Telephone: (51) +442 1921200 Ext. 5351. Fax: (51) +442 234 2958. E-mail: jlrosado@avantel.net We thank A. Cebrian, G. Concha, B. Gamez, J. Gaviño, M. Gutiérrez, G. León, A. Luna, F. Marentes, R.I. Morales, C. Sosa, G. Torres, and R. Sánchez for help in data collection, and E. Vera for chemical analyses. This research was partially supported by funding from the Spencer Foundation, Chicago, IL, USA. The authors declare they have no competing financial interests. Received 6 December 2006 ; accepted 21 May 2007.
The full version of this article is available for free in HTML or PDF formats. |
