Exposure to Arsenic and Lead and Neuropsychological Development in Mexican Children

This cross-sectional study examined the effects of chronic exposure to lead (Pb), arsenic (AS) and undernutrition on the neuropsychological development of children. Two populations chronically exposed to either high (41 children) or low (39 children) levels of As and Pb were analyzed using the Wechsler Intelligence Scale for Children, Revised Version, for México (WISC-RM). Geometric means of urinary arsenic (AsU) and lead in blood (PbB) were 62.9±0.03 (μgAs/g creatinine) and 8.9±0.03 (μg/dl) for the exposed group and 40.2±0.03 (μgAs/g creatinine) and 9.7±0.02 (μg/dl) for the reference group. The height for age index (HAI) was used as an indicator of chronic malnutrition and sociodemographic information was obtained with a questionnaire. Lead and arsenic were measured by atomic absorption spectrophotometry. Data on full, verbal, and performance intelligence quotients (IQ) scores, long-term memory, linguistic abstraction, attention span, and visuospatial organization were obtained through the WISC-RM. After controlling for significant potential confounders verbal IQ (P