Interactions between lead and essential elements: a review.

Recent clinical evidence indicates that in humans subchronic exposure to Pb during development can result in decreased developmental scores and behavioral alterations in the absence of overt neurotoxicity. The mechanism(s) by which Pb induces such alterations is unknown. Conceivably, the central nervous system (CNS) may be especially sensitive to Pb. On the other hand, deleterious effects of Pb may not be mediated directly by Pb itself. For example, perturbation of CNS function may be a manifestation of essential/trace mineral deficiencies resulting from Pb-induced impairment of mineral availability and/or increased sensitivity of the CNS to Pb intoxication in the absence of adequate levels of essential minerals. Focusing on the role of essential/trace mineral alterations is reasonable since the behavioral sequelae of neonatal Pb exposure often mimic those accompanying specific trace mineral deficiencies during this period of development. The current status of knowledge of the interactions of lead and essential elements is reviewed.