Abstract |
Forty-nine children aged 6 to 12 years were evaluated for residual effects of lead exposure using psychometric, electrophysiological, and medical tests five years after initial assessment. The original range of blood lead (PbB) levels was 6-59 micrograms/dl; the current range was 6-30 micrograms/dl. A linear relationship between PbB and slow brain wave voltage during sensory conditioning was observed at initial evaluation (Otto, et al., 1981) and at two-year follow-up (Otto, et al. 1982). No significant relationship between PbB and slow wave voltage during passive conditioning was found at five-year follow-up, although a linear increase in slow wave negativity relative to current PbB level during active conditioning was suggested by exploratory analyses. Another exploratory analysis revealed a significant linear relationship between original PbB level and the latency of waves III and V of the brainstem auditory evoked potential. |