Effects of Low to Moderate Lead Exposure on Slow Cortical Potentials in Young Children: Two Year Follow-Up Study (Journal Version)

摘要

A follow-up study of slow cortical potentials in children with elevated blood lead (PbB) histories was conducted two years after initial evaluation. An age x PbB interaction was again observed wherein slow wave (SW) voltage varied as a linear function of PbB with the slope of the function dependent on age. The linear relationship of SW voltage and PbB was significant using either original PbB values, (14-55 microgram/dl), follow-up values (11-39 microgram/dl), or the mean of the two PbB values. No evidence of a threshold for this effort was observed. The similarity of results obtained at initial and follow-up assessments suggests that the observed alterations in CNS function are persistent, despite a significant decrease in mean PbB across time. The observed change in SW voltage at PbB levels previously considered to be harmless suggests the need to reconsider the currently accepted 30 microgram/dl threshold for undue lead absorption in children.