Low Blood Lead Levels and educational achievement in 7-8 year old children in the Community of Madrid (Spain)

Resum

Background: Lead affects the behavioral and cognitive functions of children. The current lead safety level for avoiding these adverse effects is still controversial. Methods of study: A cross-sectional study included 511 children from 23 primary schools within the Comunidad de Madrid (the Madrid Region –including the city of Madrid and the large urban-industrial conurbation of satellite towns surrounding it), Spain. The children’s blood lead levels were determined by atomic absorption spectrophotometry. In addition, the teachers completed an eight-item questionnaire about the children’s behavior and academic achievement. Parents filled in a self-completion survey about the sociodemographic variables of the children and the family. Results: The mean Blood Lead Level (BLL) of the children was 4.1 µg/dL SD 1.6 µg/dL (log transformed 3.8 μg/dL SD 0.2 μg/dL). Multivariate analysis controlling for relevant sociodemographic cofactors (among others, sex, age and educational level of the parents) showed a negative association, but this was not statistically significant. Conclusions: Despite the low blood lead levels found in the children of the Comunidad de Madrid (Spain) and the design limitations of the study, the results obtained suggest the existence of a harmful, but not statistically significant, effect of blood lead on the behavior and academic achievement of children