Lead in the Environment : Experimental Studies of Lead Toxicity in Animals and Their Relevance to Marginal Lead Toxicity in Children

抄録

There are five objectives inherent in this review. First: To summarize selected aspects of the differential effect of environmental lead upon children, versus adult humans with emphasis upon the increased sensitivity of the developing brain to lead toxicity. We have reviewed experimental studies which indicate that at relatively low concentrations, lead is toxic and may be lethal to gametocytes, preimplantation embryos and is teratogenic in fetuses. Second: To provide teratologists and interested others, with diverse medical and biological backgrounds with a fundamental concept of the postnatal maturation of the cortical cells of the human brain with emphasis on animal species differentials which must be considered when trying to extrapolate such data to humans. Third: To review experimental animal studies which indicate that exposure of newborn and sucking animals to lead, hypoxia, mercury, phenobarbital, alcohol and severe inanition inhibits postnatal maturation of neurocortical cells, induces neurochemical changes which are reflected as behavioral aberrations and learning defects. Fourth: The experimental studies previously mentioned support recent clinical studies which indicate that in young children, low levels of lead exposure, do result in behavioral aberrations and learning disorders which are commonly referred to as minimal brain dysfunction. Fifth: Lead in the atmosphere is not a local problem but represents a universal problem of the biosphere which we occupy. Sustained efforts of all nations of the world to reduce the levels of human exposure to lead are essential to the health of all people and particularly children.