BLOOD LEAD LEVEL AND NEUROBEHAVIORAL DEVELOPMENT AMONG CHILDREN LIVING IN MEXICO-CITY

This cross-sectional study examined the association between blood lead levels and neuropsychological and behavioral development of 139 child ren (7-9 y of age) who attended school in the southwestern part of Mex ico City. A trained psychologist administered an IQ test to 84% of the children, and teachers graded them for agility, socialization, expres sion, and knowledge. Parents also answered a questionnaire on demograp hic and socioeconomic variables. Anodic stripping voltametry was used to determine blood lead levels. Regression models were used to determi ne the best predictors of IQ and teachers' rating scores. The mean blo od lead level was 19.4 mug/dl (standard deviation [SD] = 7.6), with a geometric mean of 17.8 mug/dl (95% confidence interval [95% Cl] = 16.5 -19.1). Blood lead was the strongest predictor of full-scale IQ, and t here was a significant negative trend between blood lead, full-scale I Q, and teachers' rating scores. In this study, children with higher le vels of blood lead performed more poorly on psychometric tests and had poorrer educational attainment than their counterparts. These results suggest an association between neuropsychological and behavioral impa irment and lead exposure.