Lead Exposure, Attentional Outcomes, and Socioenvironmental Influences
Low-level lead exposure remains a public health concern in the United States, especially among children living in older, impoverished, urban neighborhoods. Associated neurocognitive effects have been reported in global cognitive functioning (Canfield et al., 2003) and in specific neuropsychological domains (e.g., Surkan et al., 2007). This project aimed to explore the relation between concurrent blood lead level (M = 5.41 ?g/dL) and attention in a sample of 176 children. The impact of specific socioenvironmental risk and resiliency variables as well as early (24-month) blood lead concentration on the concurrent lead-attention relationship at 60-66-months was explored. Attention outcomes were nine subscales from the Conners' Parent Rating Scale - Revised Long Form (CPRS-R:L; Conners, 1997) and three scores from subtests of the Test of Everyday Attention for Children (TEA-Ch; Manly, Robertson, Anderson, & Nimmo-Smith, 1999). Principal components analysis (PCA) of the outcome variables revealed three components, externalizing symptoms, selective attention/shifting, and internalizing symptoms. These three components were the dependent variables in regression models with blood lead and risk and resiliency variables as predictors. Although each of the three overall models was significant, concurrent blood lead only emerged as a significant predictor of selective attention/shifting, and then only when a lead x sex interaction term was included. Consistent with recent reports (e.g., Ris et al., 2004; Froehlich et al., 2007), the results suggest that with respect to attention outcomes, boys may be more vulnerable to the effects of lead. That blood lead concentration was not a significant predictor of externalizing symptoms is somewhat surprising given existing literature (e.g., Braun et al., 2006; Nigg et al., 2008), though differences in outcomes, ages, and sample characteristics may explain this discrepancy. Blood lead was not found to be a significant predictor of internalizing symptoms.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:lead neurotoxin development attention cognitive function
Date of Publication:01/01/2008