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STUDIES IN CHILDREN EXPOSED TO LOW LEVELS OF LEAD
Citation:
Needleman, H. STUDIES IN CHILDREN EXPOSED TO LOW LEVELS OF LEAD. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/1-81/066.
Description:
Two separate studies were conducted with the overall objective of examining the impact of lead at low dose on the neuropsychological function of children. In the first study, a sample of children identified as having elevated lead levels in the dentine of shed deciduous teeth (N = 19) were compared to children with low dentine lead (N = 22) on electroencephalograms and a panel of 8 auditory and speech processing tasks. Quantitative electroencephalograms were obtained from 20 sites under 4 conditions in these subjects. The spectrum from 0.5 - 32 Hz was examined; four bands were studied (alpha, beta delta, and theta) under four conditions. Of the 320 comparisons, 10 differed at P - 0.025 or less (Wilcoxin-Mann, Whitney two sample test). These 10 features, nine behavioral measures previously obtained, and maternal I.Q. were then submitted to multivariate analysis. A stepwise linear discriminate function analysis showed that adding the EEG to behavioral analysis in the model increased to discriminating power from P = 0.015 to P = 0.001. The most useful diagnostic features were EEG slowing (delta) over the parietal cortex and decreased full scale I.Q.