Chapter 12 - Neurotoxicity of Lead in Human Populations

Abstract

This chapter presents the scientific and medical evidence documenting environmental lead (Pb) as a particularly potent neurotoxin for injuring the developing brain in very young children and the fetal brain during elevated Pb exposures of the mother. It mentions that Pb produces neurotoxic harm across a wide range of Pb exposures, the nature of the harm ranging from fatal outcomes at the highest exposures to demonstrable reduction in normal neurocognitive and neurobehavioral function in very young children at very low exposures. The chapter uses and merges two conceptual approaches: criticality and weight-of-evidence. The criticality concept is useful in elucidating lead's dose–toxic response relationships for an array of organ and tissue-specific toxicological data on effects which are simultaneously highly significant and occur at or among the lowest doses. Weight-of-evidence quantifies multiple lines of evidence for lead toxicity. The chapter makes distinction between Pb toxicity observed in young children qualitatively and quantitatively, and explains what comprises the typical case for older children and adults.